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Diffstat (limited to 'contrib/libpcap/pcap-rpcap.c')
| -rw-r--r-- | contrib/libpcap/pcap-rpcap.c | 3631 |
1 files changed, 3631 insertions, 0 deletions
diff --git a/contrib/libpcap/pcap-rpcap.c b/contrib/libpcap/pcap-rpcap.c new file mode 100644 index 000000000000..408d453f707a --- /dev/null +++ b/contrib/libpcap/pcap-rpcap.c @@ -0,0 +1,3631 @@ +/* + * Copyright (c) 2002 - 2005 NetGroup, Politecnico di Torino (Italy) + * Copyright (c) 2005 - 2008 CACE Technologies, Davis (California) + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the Politecnico di Torino, CACE Technologies + * nor the names of its contributors may be used to endorse or promote + * products derived from this software without specific prior written + * permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + */ + +#include <config.h> + +#include "ftmacros.h" +#include "diag-control.h" + +#include <string.h> /* for strlen(), ... */ +#include <stdlib.h> /* for malloc(), free(), ... */ +#include <stdarg.h> /* for functions with variable number of arguments */ +#include <errno.h> /* for the errno variable */ +#include <limits.h> /* for INT_MAX */ +#include "sockutils.h" +#include "pcap-int.h" +#include "pcap-util.h" +#include "rpcap-protocol.h" +#include "pcap-rpcap.h" + +#ifdef _WIN32 +#include "charconv.h" /* for utf_8_to_acp_truncated() */ +#endif + +#ifdef HAVE_OPENSSL +#include "sslutils.h" +#endif + +/* + * This file contains the pcap module for capturing from a remote machine's + * interfaces using the RPCAP protocol. + * + * WARNING: All the RPCAP functions that are allowed to return a buffer + * containing the error description can return max PCAP_ERRBUF_SIZE characters. + * However there is no guarantees that the string will be zero-terminated. + * Best practice is to define the errbuf variable as a char of size + * 'PCAP_ERRBUF_SIZE+1' and to insert manually a NULL character at the end + * of the buffer. This will guarantee that no buffer overflows occur even + * if we use the printf() to show the error on the screen. + * + * XXX - actually, null-terminating the error string is part of the + * contract for the pcap API; if there's any place in the pcap code + * that doesn't guarantee null-termination, even at the expense of + * cutting the message short, that's a bug and needs to be fixed. + */ + +#define PCAP_STATS_STANDARD 0 /* Used by pcap_stats_rpcap to see if we want standard or extended statistics */ +#ifdef _WIN32 +#define PCAP_STATS_EX 1 /* Used by pcap_stats_rpcap to see if we want standard or extended statistics */ +#endif + +/* + * \brief Keeps a list of all the opened connections in the active mode. + * + * This structure defines a linked list of items that are needed to keep the info required to + * manage the active mode. + * In other words, when a new connection in active mode starts, this structure is updated so that + * it reflects the list of active mode connections currently opened. + * This structure is required by findalldevs() and open_remote() to see if they have to open a new + * control connection toward the host, or they already have a control connection in place. + */ +struct activehosts +{ + struct sockaddr_storage host; + PCAP_SOCKET sockctrl; + SSL *ssl; + uint8 protocol_version; + int byte_swapped; + struct activehosts *next; +}; + +/* Keeps a list of all the opened connections in the active mode. */ +static struct activehosts *activeHosts; + +/* + * Keeps the main socket identifier when we want to accept a new remote + * connection (active mode only). + * See the documentation of pcap_remoteact_accept() and + * pcap_remoteact_cleanup() for more details. + */ +static PCAP_SOCKET sockmain; +static SSL *ssl_main; + +/* + * Private data for capturing remotely using the rpcap protocol. + */ +struct pcap_rpcap { + /* + * This is '1' if we're the network client; it is needed by several + * functions (such as pcap_setfilter()) to know whether they have + * to use the socket or have to open the local adapter. + */ + int rmt_clientside; + + PCAP_SOCKET rmt_sockctrl; /* socket ID of the socket used for the control connection */ + PCAP_SOCKET rmt_sockdata; /* socket ID of the socket used for the data connection */ + SSL *ctrl_ssl, *data_ssl; /* optional transport of rmt_sockctrl and rmt_sockdata via TLS */ + int rmt_flags; /* we have to save flags, since they are passed by the pcap_open_live(), but they are used by the pcap_startcapture() */ + int rmt_capstarted; /* 'true' if the capture is already started (needed to know if we have to call the pcap_startcapture() */ + char *currentfilter; /* Pointer to a buffer (allocated at run-time) that stores the current filter. Needed when flag PCAP_OPENFLAG_NOCAPTURE_RPCAP is turned on. */ + + uint8 protocol_version; /* negotiated protocol version */ + uint8 uses_ssl; /* User asked for rpcaps scheme */ + int byte_swapped; /* Server byte order is swapped from ours */ + + unsigned int TotNetDrops; /* keeps the number of packets that have been dropped by the network */ + + /* + * This keeps the number of packets that have been received by the + * application. + * + * Packets dropped by the kernel buffer are not counted in this + * variable. It is always equal to (TotAccepted - TotDrops), + * except for the case of remote capture, in which we have also + * packets in flight, i.e. that have been transmitted by the remote + * host, but that have not been received (yet) from the client. + * In this case, (TotAccepted - TotDrops - TotNetDrops) gives a + * wrong result, since this number does not corresponds always to + * the number of packet received by the application. For this reason, + * in the remote capture we need another variable that takes into + * account of the number of packets actually received by the + * application. + */ + unsigned int TotCapt; + + struct pcap_stat stat; + /* XXX */ + struct pcap *next; /* list of open pcaps that need stuff cleared on close */ +}; + +/**************************************************** + * * + * Locally defined functions * + * * + ****************************************************/ +static struct pcap_stat *rpcap_stats_rpcap(pcap_t *p, struct pcap_stat *ps, int mode); +static int pcap_pack_bpffilter(pcap_t *fp, char *sendbuf, int *sendbufidx, struct bpf_program *prog); +static int pcap_createfilter_norpcappkt(pcap_t *fp, struct bpf_program *prog); +static int pcap_updatefilter_remote(pcap_t *fp, struct bpf_program *prog); +static void pcap_save_current_filter_rpcap(pcap_t *fp, const char *filter); +static int pcap_setfilter_rpcap(pcap_t *fp, struct bpf_program *prog); +static int pcap_setsampling_remote(pcap_t *fp); +static int pcap_startcapture_remote(pcap_t *fp); +static int rpcap_recv_msg_header(PCAP_SOCKET sock, SSL *, struct rpcap_header *header, char *errbuf); +static int rpcap_check_msg_ver(PCAP_SOCKET sock, SSL *, uint8 expected_ver, struct rpcap_header *header, char *errbuf); +static int rpcap_check_msg_type(PCAP_SOCKET sock, SSL *, uint8 request_type, struct rpcap_header *header, uint16 *errcode, char *errbuf); +static int rpcap_process_msg_header(PCAP_SOCKET sock, SSL *, uint8 ver, uint8 request_type, struct rpcap_header *header, char *errbuf); +static int rpcap_recv(PCAP_SOCKET sock, SSL *, void *buffer, size_t toread, uint32 *plen, char *errbuf); +static void rpcap_msg_err(PCAP_SOCKET sockctrl, SSL *, uint32 plen, char *remote_errbuf); +static int rpcap_discard(PCAP_SOCKET sock, SSL *, uint32 len, char *errbuf); +static int rpcap_read_packet_msg(struct pcap_rpcap const *, pcap_t *p, size_t size); + +/**************************************************** + * * + * Function bodies * + * * + ****************************************************/ + +/* + * This function translates (i.e. de-serializes) a 'rpcap_sockaddr' + * structure from the network byte order to a 'sockaddr_in" or + * 'sockaddr_in6' structure in the host byte order. + * + * It accepts an 'rpcap_sockaddr' structure as it is received from the + * network, and checks the address family field against various values + * to see whether it looks like an IPv4 address, an IPv6 address, or + * neither of those. It checks for multiple values in order to try + * to handle older rpcap daemons that sent the native OS's 'sockaddr_in' + * or 'sockaddr_in6' structures over the wire with some members + * byte-swapped, and to handle the fact that AF_INET6 has different + * values on different OSes. + * + * For IPv4 addresses, it converts the address family to host byte + * order from network byte order and puts it into the structure, + * sets the length if a sockaddr structure has a length, converts the + * port number to host byte order from network byte order and puts + * it into the structure, copies over the IPv4 address, and zeroes + * out the zero padding. + * + * For IPv6 addresses, it converts the address family to host byte + * order from network byte order and puts it into the structure, + * sets the length if a sockaddr structure has a length, converts the + * port number and flow information to host byte order from network + * byte order and puts them into the structure, copies over the IPv6 + * address, and converts the scope ID to host byte order from network + * byte order and puts it into the structure. + * + * The function will allocate the 'sockaddrout' variable according to the + * address family in use. In case the address does not belong to the + * AF_INET nor AF_INET6 families, 'sockaddrout' is not allocated and a + * NULL pointer is returned. This usually happens because that address + * does not exist on the other host, or is of an address family other + * than AF_INET or AF_INET6, so the RPCAP daemon sent a 'sockaddr_storage' + * structure containing all 'zero' values. + * + * Older RPCAPDs sent the addresses over the wire in the OS's native + * structure format. For most OSes, this looks like the over-the-wire + * format, but might have a different value for AF_INET6 than the value + * on the machine receiving the reply. For OSes with the newer BSD-style + * sockaddr structures, this has, instead of a 2-byte address family, + * a 1-byte structure length followed by a 1-byte address family. The + * RPCAPD code would put the address family in network byte order before + * sending it; that would set it to 0 on a little-endian machine, as + * htons() of any value between 1 and 255 would result in a value > 255, + * with its lower 8 bits zero, so putting that back into a 1-byte field + * would set it to 0. + * + * Therefore, for older RPCAPDs running on an OS with newer BSD-style + * sockaddr structures, the family field, if treated as a big-endian + * (network byte order) 16-bit field, would be: + * + * (length << 8) | family if sent by a big-endian machine + * (length << 8) if sent by a little-endian machine + * + * For current RPCAPDs, and for older RPCAPDs running on an OS with + * older BSD-style sockaddr structures, the family field, if treated + * as a big-endian 16-bit field, would just contain the family. + * + * \param sockaddrin: a 'rpcap_sockaddr' pointer to the variable that has + * to be de-serialized. + * + * \param sockaddrout: a 'sockaddr_storage' pointer to the variable that will contain + * the de-serialized data. The structure returned can be either a 'sockaddr_in' or 'sockaddr_in6'. + * This variable will be allocated automatically inside this function. + * + * \param errbuf: a pointer to a user-allocated buffer (of size PCAP_ERRBUF_SIZE) + * that will contain the error message (in case there is one). + * + * \return '0' if everything is fine, '-1' if some errors occurred. Basically, the error + * can be only the fact that the malloc() failed to allocate memory. + * The error message is returned in the 'errbuf' variable, while the deserialized address + * is returned into the 'sockaddrout' variable. + * + * \warning This function supports only AF_INET and AF_INET6 address families. + * + * \warning The sockaddrout (if not NULL) must be deallocated by the user. + */ + +/* + * Possible IPv4 family values other than the designated over-the-wire value, + * which is 2 (because everybody, except for Haiku uses 2 for AF_INET, + * and Haiku has probably never run the old rpcapd code that put address + * structures directly on the wire, rather than the new rpcapd code + * that serializes addresses, using 2 for AF_INET). + */ +#define SOCKADDR_IN_LEN 16 /* length of struct sockaddr_in */ +#define SOCKADDR_IN6_LEN 28 /* length of struct sockaddr_in6 */ +#define NEW_BSD_AF_INET_BE ((SOCKADDR_IN_LEN << 8) | 2) +#define NEW_BSD_AF_INET_LE (SOCKADDR_IN_LEN << 8) + +/* + * Possible IPv6 family values other than the designated over-the-wire value, + * which is 23 (because that's what Windows uses, and most RPCAP servers + * out there are probably running Windows, as WinPcap includes the server + * but few if any UN*Xes build and ship it). + * + * The new BSD sockaddr structure format was in place before 4.4-Lite, so + * all the free-software BSDs use it. + */ +#define NEW_BSD_AF_INET6_BSD_BE ((SOCKADDR_IN6_LEN << 8) | 24) /* NetBSD, OpenBSD, BSD/OS */ +#define NEW_BSD_AF_INET6_FREEBSD_BE ((SOCKADDR_IN6_LEN << 8) | 28) /* FreeBSD, DragonFly BSD */ +#define NEW_BSD_AF_INET6_DARWIN_BE ((SOCKADDR_IN6_LEN << 8) | 30) /* macOS, iOS, anything else Darwin-based */ +#define NEW_BSD_AF_INET6_LE (SOCKADDR_IN6_LEN << 8) +#define LINUX_AF_INET6 10 +#define HPUX_AF_INET6 22 +#define AIX_AF_INET6 24 +#define SOLARIS_AF_INET6 26 + +static int +rpcap_deseraddr(struct rpcap_sockaddr *sockaddrin, struct sockaddr **sockaddrout, char *errbuf) +{ + /* Warning: we support only AF_INET and AF_INET6 */ + switch (ntohs(sockaddrin->family)) + { + case RPCAP_AF_INET: + case NEW_BSD_AF_INET_BE: + case NEW_BSD_AF_INET_LE: + { + struct rpcap_sockaddr_in *sockaddrin_ipv4; + struct sockaddr_in *sockaddrout_ipv4; + + (*sockaddrout) = (struct sockaddr *) malloc(sizeof(struct sockaddr_in)); + if ((*sockaddrout) == NULL) + { + pcapint_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, + errno, "malloc() failed"); + return -1; + } + sockaddrin_ipv4 = (struct rpcap_sockaddr_in *) sockaddrin; + sockaddrout_ipv4 = (struct sockaddr_in *) (*sockaddrout); + sockaddrout_ipv4->sin_family = AF_INET; + sockaddrout_ipv4->sin_port = ntohs(sockaddrin_ipv4->port); + memcpy(&sockaddrout_ipv4->sin_addr, &sockaddrin_ipv4->addr, sizeof(sockaddrout_ipv4->sin_addr)); + memset(sockaddrout_ipv4->sin_zero, 0, sizeof(sockaddrout_ipv4->sin_zero)); + break; + } + +#ifdef AF_INET6 + case RPCAP_AF_INET6: + case NEW_BSD_AF_INET6_BSD_BE: + case NEW_BSD_AF_INET6_FREEBSD_BE: + case NEW_BSD_AF_INET6_DARWIN_BE: + case NEW_BSD_AF_INET6_LE: + case LINUX_AF_INET6: + case HPUX_AF_INET6: + case AIX_AF_INET6: + case SOLARIS_AF_INET6: + { + struct rpcap_sockaddr_in6 *sockaddrin_ipv6; + struct sockaddr_in6 *sockaddrout_ipv6; + + (*sockaddrout) = (struct sockaddr *) malloc(sizeof(struct sockaddr_in6)); + if ((*sockaddrout) == NULL) + { + pcapint_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, + errno, "malloc() failed"); + return -1; + } + sockaddrin_ipv6 = (struct rpcap_sockaddr_in6 *) sockaddrin; + sockaddrout_ipv6 = (struct sockaddr_in6 *) (*sockaddrout); + sockaddrout_ipv6->sin6_family = AF_INET6; + sockaddrout_ipv6->sin6_port = ntohs(sockaddrin_ipv6->port); + sockaddrout_ipv6->sin6_flowinfo = ntohl(sockaddrin_ipv6->flowinfo); + memcpy(&sockaddrout_ipv6->sin6_addr, &sockaddrin_ipv6->addr, sizeof(sockaddrout_ipv6->sin6_addr)); + sockaddrout_ipv6->sin6_scope_id = ntohl(sockaddrin_ipv6->scope_id); + break; + } +#endif + + default: + /* + * It is neither AF_INET nor AF_INET6 (or, if the OS doesn't + * support AF_INET6, it's not AF_INET). + */ + *sockaddrout = NULL; + break; + } + return 0; +} + +/* + * This function reads a packet from the network socket. It does not + * deliver the packet to a pcap_dispatch()/pcap_loop() callback (hence + * the "nocb" string into its name). + * + * This function is called by pcap_read_rpcap(). + * + * WARNING: By choice, this function does not make use of semaphores. A smarter + * implementation should put a semaphore into the data thread, and a signal will + * be raised as soon as there is data into the socket buffer. + * However this is complicated and it does not bring any advantages when reading + * from the network, in which network delays can be much more important than + * these optimizations. Therefore, we chose the following approach: + * - the 'timeout' chosen by the user is split in two (half on the server side, + * with the usual meaning, and half on the client side) + * - this function checks for packets; if there are no packets, it waits for + * timeout/2 and then it checks again. If packets are still missing, it returns, + * otherwise it reads packets. + */ +static int pcap_read_nocb_remote(pcap_t *p, struct pcap_pkthdr *pkt_header, u_char **pkt_data) +{ + struct pcap_rpcap *pr = p->priv; /* structure used when doing a remote live capture */ + struct rpcap_header *header; /* general header according to the RPCAP format */ + struct rpcap_pkthdr *net_pkt_header; /* header of the packet, from the message */ + u_char *net_pkt_data; /* packet data from the message */ + uint32 plen; + int retval = 0; /* generic return value */ + int msglen; + + /* Structures needed for the select() call */ + struct timeval tv; /* maximum time the select() can block waiting for data */ + fd_set rfds; /* set of socket descriptors we have to check */ + + /* + * Define the packet buffer timeout, to be used in the select() + * 'timeout', in pcap_t, is in milliseconds; we have to convert it into sec and microsec + */ + tv.tv_sec = p->opt.timeout / 1000; + tv.tv_usec = (suseconds_t)((p->opt.timeout - tv.tv_sec * 1000) * 1000); + +#ifdef HAVE_OPENSSL + /* Check if we still have bytes available in the last decoded TLS record. + * If that's the case, we know SSL_read will not block. */ + retval = pr->data_ssl && SSL_pending(pr->data_ssl) > 0; +#endif + if (! retval) + { + /* Watch out sockdata to see if it has input */ + FD_ZERO(&rfds); + + /* + * 'fp->rmt_sockdata' has always to be set before calling the select(), + * since it is cleared by the select() + */ + FD_SET(pr->rmt_sockdata, &rfds); + +#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION + retval = 1; +#else + retval = select((int) pr->rmt_sockdata + 1, &rfds, NULL, NULL, &tv); +#endif + + if (retval == -1) + { +#ifndef _WIN32 + if (errno == EINTR) + { + /* Interrupted. */ + return 0; + } +#endif + sock_geterrmsg(p->errbuf, PCAP_ERRBUF_SIZE, + "select() failed"); + return -1; + } + } + + /* There is no data waiting, so return '0' */ + if (retval == 0) + return 0; + + /* + * We have to define 'header' as a pointer to a larger buffer, + * because in case of UDP we have to read all the message within a single call + */ + header = (struct rpcap_header *) p->buffer; + net_pkt_header = (struct rpcap_pkthdr *) ((char *)p->buffer + sizeof(struct rpcap_header)); + net_pkt_data = (u_char *)p->buffer + sizeof(struct rpcap_header) + sizeof(struct rpcap_pkthdr); + + if (pr->rmt_flags & PCAP_OPENFLAG_DATATX_UDP) + { + /* Read the entire message from the network */ + msglen = sock_recv_dgram(pr->rmt_sockdata, pr->data_ssl, p->buffer, + p->bufsize, p->errbuf, PCAP_ERRBUF_SIZE); + if (msglen == -1) + { + /* Network error. */ + return -1; + } + if (msglen == -3) + { + /* Interrupted receive. */ + return 0; + } + if ((size_t)msglen < sizeof(struct rpcap_header)) + { + /* + * Message is shorter than an rpcap header. + */ + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "UDP packet message is shorter than an rpcap header"); + return -1; + } + plen = ntohl(header->plen); + if ((size_t)msglen < sizeof(struct rpcap_header) + plen) + { + /* + * Message is shorter than the header claims it + * is. + */ + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "UDP packet message is shorter than its rpcap header claims"); + return -1; + } + } + else + { + int status; + + if ((size_t)p->cc < sizeof(struct rpcap_header)) + { + /* + * We haven't read any of the packet header yet. + * The size we should get is the size of the + * packet header. + */ + status = rpcap_read_packet_msg(pr, p, sizeof(struct rpcap_header)); + if (status == -1) + { + /* Network error. */ + return -1; + } + if (status == -3) + { + /* Interrupted receive. */ + return 0; + } + } + + /* + * We have the header, so we know how long the + * message payload is. The size we should get + * is the size of the packet header plus the + * size of the payload. + */ + plen = ntohl(header->plen); + if (plen > p->bufsize - sizeof(struct rpcap_header)) + { + /* + * This is bigger than the largest + * record we'd expect. (We do it by + * subtracting in order to avoid an + * overflow.) + */ + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "Server sent us a message larger than the largest expected packet message"); + return -1; + } + status = rpcap_read_packet_msg(pr, p, sizeof(struct rpcap_header) + plen); + if (status == -1) + { + /* Network error. */ + return -1; + } + if (status == -3) + { + /* Interrupted receive. */ + return 0; + } + + /* + * We have the entire message; reset the buffer pointer + * and count, as the next read should start a new + * message. + */ + p->bp = p->buffer; + p->cc = 0; + } + + /* + * We have the entire message. + */ + header->plen = plen; + + /* + * Did the server specify the version we negotiated? + */ + if (rpcap_check_msg_ver(pr->rmt_sockdata, pr->data_ssl, pr->protocol_version, + header, p->errbuf) == -1) + { + return 0; /* Return 'no packets received' */ + } + + /* + * Is this a RPCAP_MSG_PACKET message? + */ + if (header->type != RPCAP_MSG_PACKET) + { + return 0; /* Return 'no packets received' */ + } + + if (ntohl(net_pkt_header->caplen) > plen) + { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "Packet's captured data goes past the end of the received packet message."); + return -1; + } + + /* Fill in packet header */ + pkt_header->caplen = ntohl(net_pkt_header->caplen); + pkt_header->len = ntohl(net_pkt_header->len); + pkt_header->ts.tv_sec = ntohl(net_pkt_header->timestamp_sec); + pkt_header->ts.tv_usec = ntohl(net_pkt_header->timestamp_usec); + + /* Supply a pointer to the beginning of the packet data */ + *pkt_data = net_pkt_data; + + /* + * I don't update the counter of the packets dropped by the network since we're using TCP, + * therefore no packets are dropped. Just update the number of packets received correctly + */ + pr->TotCapt++; + + if (pr->rmt_flags & PCAP_OPENFLAG_DATATX_UDP) + { + unsigned int npkt; + + /* We're using UDP, so we need to update the counter of the packets dropped by the network */ + npkt = ntohl(net_pkt_header->npkt); + + if (pr->TotCapt != npkt) + { + pr->TotNetDrops += (npkt - pr->TotCapt); + pr->TotCapt = npkt; + } + } + + /* Packet read successfully */ + return 1; +} + +/* + * This function reads a packet from the network socket. + * + * This function relies on the pcap_read_nocb_remote to deliver packets. The + * difference, here, is that as soon as a packet is read, it is delivered + * to the application by means of a callback function. + */ +static int pcap_read_rpcap(pcap_t *p, int cnt, pcap_handler callback, u_char *user) +{ + struct pcap_rpcap *pr = p->priv; /* structure used when doing a remote live capture */ + struct pcap_pkthdr pkt_header; + u_char *pkt_data; + int n = 0; + int ret; + + /* + * If this is client-side, and we haven't already started + * the capture, start it now. + */ + if (pr->rmt_clientside) + { + /* We are on an remote capture */ + if (!pr->rmt_capstarted) + { + /* + * The capture isn't started yet, so try to + * start it. + */ + if (pcap_startcapture_remote(p)) + return -1; + } + } + + /* + * This can conceivably process more than INT_MAX packets, + * which would overflow the packet count, causing it either + * to look like a negative number, and thus cause us to + * return a value that looks like an error, or overflow + * back into positive territory, and thus cause us to + * return a too-low count. + * + * Therefore, if the packet count is unlimited, we clip + * it at INT_MAX; this routine is not expected to + * process packets indefinitely, so that's not an issue. + */ + if (PACKET_COUNT_IS_UNLIMITED(cnt)) + cnt = INT_MAX; + + while (n < cnt || PACKET_COUNT_IS_UNLIMITED(cnt)) + { + /* + * Has "pcap_breakloop()" been called? + */ + if (p->break_loop) { + /* + * Yes - clear the flag that indicates that it + * has, and return PCAP_ERROR_BREAK to indicate + * that we were told to break out of the loop. + */ + p->break_loop = 0; + return (PCAP_ERROR_BREAK); + } + + /* + * Read some packets. + */ + ret = pcap_read_nocb_remote(p, &pkt_header, &pkt_data); + if (ret == 1) + { + /* + * We got a packet. + * + * Do whatever post-processing is necessary, hand + * it to the callback, and count it so we can + * return the count. + */ + pcapint_post_process(p->linktype, pr->byte_swapped, + &pkt_header, pkt_data); + (*callback)(user, &pkt_header, pkt_data); + n++; + } + else if (ret == -1) + { + /* Error. */ + return ret; + } + else + { + /* + * No packet; this could mean that we timed + * out, or that we got interrupted, or that + * we got a bad packet. + * + * Were we told to break out of the loop? + */ + if (p->break_loop) { + /* + * Yes. + */ + p->break_loop = 0; + return (PCAP_ERROR_BREAK); + } + /* No - return the number of packets we've processed. */ + return n; + } + } + return n; +} + +/* + * This function sends a CLOSE command to the capture server if we're in + * passive mode and an ENDCAP command to the capture server if we're in + * active mode. + * + * It is called when the user calls pcap_close(). It sends a command + * to our peer that says 'ok, let's stop capturing'. + * + * WARNING: Since we're closing the connection, we do not check for errors. + */ +static void pcap_cleanup_rpcap(pcap_t *fp) +{ + struct pcap_rpcap *pr = fp->priv; /* structure used when doing a remote live capture */ + struct rpcap_header header; /* header of the RPCAP packet */ + struct activehosts *temp; /* temp var needed to scan the host list chain, to detect if we're in active mode */ + int active = 0; /* active mode or not? */ + + /* detect if we're in active mode */ + temp = activeHosts; + while (temp) + { + if (temp->sockctrl == pr->rmt_sockctrl) + { + active = 1; + break; + } + temp = temp->next; + } + + if (!active) + { + rpcap_createhdr(&header, pr->protocol_version, + RPCAP_MSG_CLOSE, 0, 0); + + /* + * Send the close request; don't report any errors, as + * we're closing this pcap_t, and have no place to report + * the error. No reply is sent to this message. + */ + (void)sock_send(pr->rmt_sockctrl, pr->ctrl_ssl, (char *)&header, + sizeof(struct rpcap_header), NULL, 0); + } + else + { + rpcap_createhdr(&header, pr->protocol_version, + RPCAP_MSG_ENDCAP_REQ, 0, 0); + + /* + * Send the end capture request; don't report any errors, + * as we're closing this pcap_t, and have no place to + * report the error. + */ + if (sock_send(pr->rmt_sockctrl, pr->ctrl_ssl, (char *)&header, + sizeof(struct rpcap_header), NULL, 0) == 0) + { + /* + * Wait for the answer; don't report any errors, + * as we're closing this pcap_t, and have no + * place to report the error. + */ + if (rpcap_process_msg_header(pr->rmt_sockctrl, pr->ctrl_ssl, + pr->protocol_version, RPCAP_MSG_ENDCAP_REQ, + &header, NULL) == 0) + { + (void)rpcap_discard(pr->rmt_sockctrl, pr->ctrl_ssl, + header.plen, NULL); + } + } + } + + if (pr->rmt_sockdata) + { +#ifdef HAVE_OPENSSL + if (pr->data_ssl) + { + // Finish using the SSL handle for the data socket. + // This must be done *before* the socket is closed. + ssl_finish(pr->data_ssl); + pr->data_ssl = NULL; + } +#endif + sock_close(pr->rmt_sockdata, NULL, 0); + pr->rmt_sockdata = 0; + } + + if ((!active) && (pr->rmt_sockctrl)) + { +#ifdef HAVE_OPENSSL + if (pr->ctrl_ssl) + { + // Finish using the SSL handle for the control socket. + // This must be done *before* the socket is closed. + ssl_finish(pr->ctrl_ssl); + pr->ctrl_ssl = NULL; + } +#endif + sock_close(pr->rmt_sockctrl, NULL, 0); + } + + pr->rmt_sockctrl = 0; + pr->ctrl_ssl = NULL; + + if (pr->currentfilter) + { + free(pr->currentfilter); + pr->currentfilter = NULL; + } + + pcapint_cleanup_live_common(fp); + + /* To avoid inconsistencies in the number of sock_init() */ + sock_cleanup(); +} + +/* + * This function retrieves network statistics from our peer; + * it provides only the standard statistics. + */ +static int pcap_stats_rpcap(pcap_t *p, struct pcap_stat *ps) +{ + struct pcap_stat *retval; + + retval = rpcap_stats_rpcap(p, ps, PCAP_STATS_STANDARD); + + if (retval) + return 0; + else + return -1; +} + +#ifdef _WIN32 +/* + * This function retrieves network statistics from our peer; + * it provides the additional statistics supported by pcap_stats_ex(). + */ +static struct pcap_stat *pcap_stats_ex_rpcap(pcap_t *p, int *pcap_stat_size) +{ + *pcap_stat_size = sizeof (p->stat); + + /* PCAP_STATS_EX (third param) means 'extended pcap_stats()' */ + return (rpcap_stats_rpcap(p, &(p->stat), PCAP_STATS_EX)); +} +#endif + +/* + * This function retrieves network statistics from our peer. It + * is used by the two previous functions. + * + * It can be called in two modes: + * - PCAP_STATS_STANDARD: if we want just standard statistics (i.e., + * for pcap_stats()) + * - PCAP_STATS_EX: if we want extended statistics (i.e., for + * pcap_stats_ex()) + * + * This 'mode' parameter is needed because in pcap_stats() the variable that + * keeps the statistics is allocated by the user. On Windows, this structure + * has been extended in order to keep new stats. However, if the user has a + * smaller structure and it passes it to pcap_stats(), this function will + * try to fill in more data than the size of the structure, so that memory + * after the structure will be overwritten. + * + * So, we need to know it we have to copy just the standard fields, or the + * extended fields as well. + * + * In case we want to copy the extended fields as well, the problem of + * memory overflow no longer exists because the structure that's filled + * in is part of the pcap_t, so that it can be guaranteed to be large + * enough for the additional statistics. + * + * \param p: the pcap_t structure related to the current instance. + * + * \param ps: a pointer to a 'pcap_stat' structure, needed for compatibility + * with pcap_stat(), where the structure is allocated by the user. In case + * of pcap_stats_ex(), this structure and the function return value point + * to the same variable. + * + * \param mode: one of PCAP_STATS_STANDARD or PCAP_STATS_EX. + * + * \return The structure that keeps the statistics, or NULL in case of error. + * The error string is placed in the pcap_t structure. + */ +static struct pcap_stat *rpcap_stats_rpcap(pcap_t *p, struct pcap_stat *ps, int mode) +{ + struct pcap_rpcap *pr = p->priv; /* structure used when doing a remote live capture */ + struct rpcap_header header; /* header of the RPCAP packet */ + struct rpcap_stats netstats; /* statistics sent on the network */ + uint32 plen; /* data remaining in the message */ + +#ifdef _WIN32 + if (mode != PCAP_STATS_STANDARD && mode != PCAP_STATS_EX) +#else + if (mode != PCAP_STATS_STANDARD) +#endif + { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "Invalid stats mode %d", mode); + return NULL; + } + + /* + * If the capture has not yet started, we cannot request statistics + * for the capture from our peer, so we return 0 for all statistics, + * as nothing's been seen yet. + */ + if (!pr->rmt_capstarted) + { + ps->ps_drop = 0; + ps->ps_ifdrop = 0; + ps->ps_recv = 0; +#ifdef _WIN32 + if (mode == PCAP_STATS_EX) + { + ps->ps_capt = 0; + ps->ps_sent = 0; + ps->ps_netdrop = 0; + } +#endif /* _WIN32 */ + + return ps; + } + + rpcap_createhdr(&header, pr->protocol_version, + RPCAP_MSG_STATS_REQ, 0, 0); + + /* Send the PCAP_STATS command */ + if (sock_send(pr->rmt_sockctrl, pr->ctrl_ssl, (char *)&header, + sizeof(struct rpcap_header), p->errbuf, PCAP_ERRBUF_SIZE) < 0) + return NULL; /* Unrecoverable network error */ + + /* Receive and process the reply message header. */ + if (rpcap_process_msg_header(pr->rmt_sockctrl, pr->ctrl_ssl, pr->protocol_version, + RPCAP_MSG_STATS_REQ, &header, p->errbuf) == -1) + return NULL; /* Error */ + + plen = header.plen; + + /* Read the reply body */ + if (rpcap_recv(pr->rmt_sockctrl, pr->ctrl_ssl, (char *)&netstats, + sizeof(struct rpcap_stats), &plen, p->errbuf) == -1) + goto error; + + ps->ps_drop = ntohl(netstats.krnldrop); + ps->ps_ifdrop = ntohl(netstats.ifdrop); + ps->ps_recv = ntohl(netstats.ifrecv); +#ifdef _WIN32 + if (mode == PCAP_STATS_EX) + { + ps->ps_capt = pr->TotCapt; + ps->ps_netdrop = pr->TotNetDrops; + ps->ps_sent = ntohl(netstats.svrcapt); + } +#endif /* _WIN32 */ + + /* Discard the rest of the message. */ + if (rpcap_discard(pr->rmt_sockctrl, pr->ctrl_ssl, plen, p->errbuf) == -1) + goto error_nodiscard; + + return ps; + +error: + /* + * Discard the rest of the message. + * We already reported an error; if this gets an error, just + * drive on. + */ + (void)rpcap_discard(pr->rmt_sockctrl, pr->ctrl_ssl, plen, NULL); + +error_nodiscard: + return NULL; +} + +/* + * This function returns the entry in the list of active hosts for this + * active connection (active mode only), or NULL if there is no + * active connection or an error occurred. It is just for internal + * use. + * + * \param host: a string that keeps the host name of the host for which we + * want to get the socket ID for that active connection. + * + * \param error: a pointer to an int that is set to 1 if an error occurred + * and 0 otherwise. + * + * \param errbuf: a pointer to a user-allocated buffer (of size + * PCAP_ERRBUF_SIZE) that will contain the error message (in case + * there is one). + * + * \return the entry for this host in the list of active connections + * if found, NULL if it's not found or there's an error. + */ +static struct activehosts * +rpcap_remoteact_getsock(const char *host, int *error, char *errbuf) +{ + struct activehosts *temp; /* temp var needed to scan the host list chain */ + struct addrinfo hints, *addrinfo, *ai_next; /* temp var needed to translate between hostname to its address */ + + /* retrieve the network address corresponding to 'host' */ + addrinfo = NULL; + memset(&hints, 0, sizeof(struct addrinfo)); + hints.ai_family = PF_UNSPEC; + hints.ai_socktype = SOCK_STREAM; + + addrinfo = sock_initaddress(host, NULL, &hints, errbuf, + PCAP_ERRBUF_SIZE); + if (addrinfo == NULL) + { + *error = 1; + return NULL; + } + + temp = activeHosts; + + while (temp) + { + ai_next = addrinfo; + while (ai_next) + { + if (sock_cmpaddr(&temp->host, (struct sockaddr_storage *) ai_next->ai_addr) == 0) + { + *error = 0; + freeaddrinfo(addrinfo); + return temp; + } + + ai_next = ai_next->ai_next; + } + temp = temp->next; + } + + if (addrinfo) + freeaddrinfo(addrinfo); + + /* + * The host for which you want to get the socket ID does not have an + * active connection. + */ + *error = 0; + return NULL; +} + +/* + * This function starts a remote capture. + * + * This function is required since the RPCAP protocol decouples the 'open' + * from the 'start capture' functions. + * This function takes all the parameters needed (which have been stored + * into the pcap_t structure) and sends them to the server. + * + * \param fp: the pcap_t descriptor of the device currently open. + * + * \return '0' if everything is fine, '-1' otherwise. The error message + * (if one) is returned into the 'errbuf' field of the pcap_t structure. + */ +static int pcap_startcapture_remote(pcap_t *fp) +{ + struct pcap_rpcap *pr = fp->priv; /* structure used when doing a remote live capture */ + char sendbuf[RPCAP_NETBUF_SIZE]; /* temporary buffer in which data to be sent is buffered */ + int sendbufidx = 0; /* index which keeps the number of bytes currently buffered */ + uint16 portdata = 0; /* temp variable needed to keep the network port for the data connection */ + uint32 plen; + int active = 0; /* '1' if we're in active mode */ + struct activehosts *temp; /* temp var needed to scan the host list chain, to detect if we're in active mode */ + char host[INET6_ADDRSTRLEN + 1]; /* numeric name of the other host */ + + /* socket-related variables*/ + struct addrinfo hints; /* temp, needed to open a socket connection */ + struct addrinfo *addrinfo; /* temp, needed to open a socket connection */ + PCAP_SOCKET sockdata = 0; /* socket descriptor of the data connection */ + struct sockaddr_storage saddr; /* temp, needed to retrieve the network data port chosen on the local machine */ + socklen_t saddrlen; /* temp, needed to retrieve the network data port chosen on the local machine */ + int ai_family; /* temp, keeps the address family used by the control connection */ + struct sockaddr_in *sin4; + struct sockaddr_in6 *sin6; + + /* RPCAP-related variables*/ + struct rpcap_header header; /* header of the RPCAP packet */ + struct rpcap_startcapreq *startcapreq; /* start capture request message */ + struct rpcap_startcapreply startcapreply; /* start capture reply message */ + + /* Variables related to the buffer setting */ + int res; + socklen_t itemp; + int sockbufsize = 0; + uint32 server_sockbufsize; + + // Take the opportunity to clear pr->data_ssl before any goto error, + // as it seems p->priv is not zeroed after its malloced. + // XXX - it now should be, as it's allocated by pcap_alloc_pcap_t(), + // which does a calloc(). + pr->data_ssl = NULL; + + /* + * Let's check if sampling has been required. + * If so, let's set it first + */ + if (pcap_setsampling_remote(fp) != 0) + return -1; + + /* detect if we're in active mode */ + temp = activeHosts; + while (temp) + { + if (temp->sockctrl == pr->rmt_sockctrl) + { + active = 1; + break; + } + temp = temp->next; + } + + addrinfo = NULL; + + /* + * Gets the complete sockaddr structure used in the ctrl connection + * This is needed to get the address family of the control socket + * Tip: I cannot save the ai_family of the ctrl sock in the pcap_t struct, + * since the ctrl socket can already be open in case of active mode; + * so I would have to call getpeername() anyway + */ + saddrlen = sizeof(struct sockaddr_storage); + if (getpeername(pr->rmt_sockctrl, (struct sockaddr *) &saddr, &saddrlen) == -1) + { + sock_geterrmsg(fp->errbuf, PCAP_ERRBUF_SIZE, + "getsockname() failed"); + goto error_nodiscard; + } + ai_family = ((struct sockaddr_storage *) &saddr)->ss_family; + + /* Get the numeric address of the remote host we are connected to */ + if (getnameinfo((struct sockaddr *) &saddr, saddrlen, host, + sizeof(host), NULL, 0, NI_NUMERICHOST)) + { + sock_geterrmsg(fp->errbuf, PCAP_ERRBUF_SIZE, + "getnameinfo() failed"); + goto error_nodiscard; + } + + /* + * Data connection is opened by the server toward the client if: + * - we're using TCP, and the user wants us to be in active mode + * - we're using UDP + */ + if ((active) || (pr->rmt_flags & PCAP_OPENFLAG_DATATX_UDP)) + { + /* + * We have to create a new socket to receive packets + * We have to do that immediately, since we have to tell the other + * end which network port we picked up + */ + memset(&hints, 0, sizeof(struct addrinfo)); + /* TEMP addrinfo is NULL in case of active */ + hints.ai_family = ai_family; /* Use the same address family of the control socket */ + hints.ai_socktype = (pr->rmt_flags & PCAP_OPENFLAG_DATATX_UDP) ? SOCK_DGRAM : SOCK_STREAM; + hints.ai_flags = AI_PASSIVE; /* Data connection is opened by the server toward the client */ + + /* Let's the server pick up a free network port for us */ + addrinfo = sock_initaddress(NULL, NULL, &hints, fp->errbuf, + PCAP_ERRBUF_SIZE); + if (addrinfo == NULL) + goto error_nodiscard; + + if ((sockdata = sock_open(NULL, addrinfo, SOCKOPEN_SERVER, + 1 /* max 1 connection in queue */, fp->errbuf, PCAP_ERRBUF_SIZE)) == INVALID_SOCKET) + goto error_nodiscard; + + /* addrinfo is no longer used */ + freeaddrinfo(addrinfo); + addrinfo = NULL; + + /* get the complete sockaddr structure used in the data connection */ + saddrlen = sizeof(struct sockaddr_storage); + if (getsockname(sockdata, (struct sockaddr *) &saddr, &saddrlen) == -1) + { + sock_geterrmsg(fp->errbuf, PCAP_ERRBUF_SIZE, + "getsockname() failed"); + goto error_nodiscard; + } + + switch (saddr.ss_family) { + + case AF_INET: + sin4 = (struct sockaddr_in *)&saddr; + portdata = sin4->sin_port; + break; + + case AF_INET6: + sin6 = (struct sockaddr_in6 *)&saddr; + portdata = sin6->sin6_port; + break; + + default: + snprintf(fp->errbuf, PCAP_ERRBUF_SIZE, + "Local address has unknown address family %u", + saddr.ss_family); + goto error_nodiscard; + } + } + + /* + * Now it's time to start playing with the RPCAP protocol + * RPCAP start capture command: create the request message + */ + if (sock_bufferize(NULL, sizeof(struct rpcap_header), NULL, + &sendbufidx, RPCAP_NETBUF_SIZE, SOCKBUF_CHECKONLY, fp->errbuf, PCAP_ERRBUF_SIZE)) + goto error_nodiscard; + + rpcap_createhdr((struct rpcap_header *) sendbuf, + pr->protocol_version, RPCAP_MSG_STARTCAP_REQ, 0, + sizeof(struct rpcap_startcapreq) + sizeof(struct rpcap_filter) + fp->fcode.bf_len * sizeof(struct rpcap_filterbpf_insn)); + + /* Fill the structure needed to open an adapter remotely */ + startcapreq = (struct rpcap_startcapreq *) &sendbuf[sendbufidx]; + + if (sock_bufferize(NULL, sizeof(struct rpcap_startcapreq), NULL, + &sendbufidx, RPCAP_NETBUF_SIZE, SOCKBUF_CHECKONLY, fp->errbuf, PCAP_ERRBUF_SIZE)) + goto error_nodiscard; + + memset(startcapreq, 0, sizeof(struct rpcap_startcapreq)); + + /* By default, apply half the timeout on one side, half of the other */ + fp->opt.timeout = fp->opt.timeout / 2; + startcapreq->read_timeout = htonl(fp->opt.timeout); + + /* portdata on the openreq is meaningful only if we're in active mode */ + if ((active) || (pr->rmt_flags & PCAP_OPENFLAG_DATATX_UDP)) + { + startcapreq->portdata = portdata; + } + + startcapreq->snaplen = htonl(fp->snapshot); + startcapreq->flags = 0; + + if (pr->rmt_flags & PCAP_OPENFLAG_PROMISCUOUS) + startcapreq->flags |= RPCAP_STARTCAPREQ_FLAG_PROMISC; + if (pr->rmt_flags & PCAP_OPENFLAG_DATATX_UDP) + startcapreq->flags |= RPCAP_STARTCAPREQ_FLAG_DGRAM; + if (active) + startcapreq->flags |= RPCAP_STARTCAPREQ_FLAG_SERVEROPEN; + + startcapreq->flags = htons(startcapreq->flags); + + /* Pack the capture filter */ + if (pcap_pack_bpffilter(fp, &sendbuf[sendbufidx], &sendbufidx, &fp->fcode)) + goto error_nodiscard; + + if (sock_send(pr->rmt_sockctrl, pr->ctrl_ssl, sendbuf, sendbufidx, fp->errbuf, + PCAP_ERRBUF_SIZE) < 0) + goto error_nodiscard; + + /* Receive and process the reply message header. */ + if (rpcap_process_msg_header(pr->rmt_sockctrl, pr->ctrl_ssl, pr->protocol_version, + RPCAP_MSG_STARTCAP_REQ, &header, fp->errbuf) == -1) + goto error_nodiscard; + + plen = header.plen; + + if (rpcap_recv(pr->rmt_sockctrl, pr->ctrl_ssl, (char *)&startcapreply, + sizeof(struct rpcap_startcapreply), &plen, fp->errbuf) == -1) + goto error; + + /* + * In case of UDP data stream, the connection is always opened by the daemon + * So, this case is already covered by the code above. + * Now, we have still to handle TCP connections, because: + * - if we're in active mode, we have to wait for a remote connection + * - if we're in passive more, we have to start a connection + * + * We have to do he job in two steps because in case we're opening a TCP connection, we have + * to tell the port we're using to the remote side; in case we're accepting a TCP + * connection, we have to wait this info from the remote side. + */ + if (!(pr->rmt_flags & PCAP_OPENFLAG_DATATX_UDP)) + { + if (!active) + { + char portstring[PCAP_BUF_SIZE]; + + memset(&hints, 0, sizeof(struct addrinfo)); + hints.ai_family = ai_family; /* Use the same address family of the control socket */ + hints.ai_socktype = (pr->rmt_flags & PCAP_OPENFLAG_DATATX_UDP) ? SOCK_DGRAM : SOCK_STREAM; + snprintf(portstring, PCAP_BUF_SIZE, "%d", ntohs(startcapreply.portdata)); + + /* Let's the server pick up a free network port for us */ + addrinfo = sock_initaddress(host, portstring, &hints, + fp->errbuf, PCAP_ERRBUF_SIZE); + if (addrinfo == NULL) + goto error; + + if ((sockdata = sock_open(host, addrinfo, SOCKOPEN_CLIENT, 0, fp->errbuf, PCAP_ERRBUF_SIZE)) == INVALID_SOCKET) + goto error; + + /* addrinfo is no longer used */ + freeaddrinfo(addrinfo); + addrinfo = NULL; + } + else + { + PCAP_SOCKET socktemp; /* We need another socket, since we're going to accept() a connection */ + + /* Connection creation */ + saddrlen = sizeof(struct sockaddr_storage); + + socktemp = accept(sockdata, (struct sockaddr *) &saddr, &saddrlen); + + if (socktemp == INVALID_SOCKET) + { + sock_geterrmsg(fp->errbuf, PCAP_ERRBUF_SIZE, + "accept() failed"); + goto error; + } + + /* Now that I accepted the connection, the server socket is no longer needed */ + sock_close(sockdata, fp->errbuf, PCAP_ERRBUF_SIZE); + sockdata = socktemp; + } + } + + /* Let's save the socket of the data connection */ + pr->rmt_sockdata = sockdata; + +#ifdef HAVE_OPENSSL + if (pr->uses_ssl) + { + pr->data_ssl = ssl_promotion(0, sockdata, fp->errbuf, PCAP_ERRBUF_SIZE); + if (! pr->data_ssl) goto error; + } +#endif + + /* + * Set the size of the socket buffer for the data socket. + * It has the same size as the local capture buffer used + * on the other side of the connection. + */ + server_sockbufsize = ntohl(startcapreply.bufsize); + + /* Let's get the actual size of the socket buffer */ + itemp = sizeof(sockbufsize); + + res = getsockopt(sockdata, SOL_SOCKET, SO_RCVBUF, (char *)&sockbufsize, &itemp); + if (res == -1) + { + sock_geterrmsg(fp->errbuf, PCAP_ERRBUF_SIZE, + "pcap_startcapture_remote(): getsockopt() failed"); + goto error; + } + + /* + * Warning: on some kernels (e.g. Linux), the size of the user + * buffer does not take into account the pcap_header and such, + * and it is set equal to the snaplen. + * + * In my view, this is wrong (the meaning of the bufsize became + * a bit strange). So, here bufsize is the whole size of the + * user buffer. In case the bufsize returned is too small, + * let's adjust it accordingly. + */ + if (server_sockbufsize <= (u_int) fp->snapshot) + server_sockbufsize += sizeof(struct pcap_pkthdr); + + /* if the current socket buffer is smaller than the desired one */ + if ((u_int) sockbufsize < server_sockbufsize) + { + /* + * Loop until the buffer size is OK or the original + * socket buffer size is larger than this one. + */ + for (;;) + { + res = setsockopt(sockdata, SOL_SOCKET, SO_RCVBUF, + (char *)&(server_sockbufsize), + sizeof(server_sockbufsize)); + + if (res == 0) + break; + + /* + * If something goes wrong, halve the buffer size + * (checking that it does not become smaller than + * the current one). + */ + server_sockbufsize /= 2; + + if ((u_int) sockbufsize >= server_sockbufsize) + { + server_sockbufsize = sockbufsize; + break; + } + } + } + + /* + * Let's allocate the packet; this is required in order to put + * the packet somewhere when extracting data from the socket. + * Since buffering has already been done in the socket buffer, + * here we need just a buffer whose size is equal to the + * largest possible packet message for the snapshot size, + * namely the length of the message header plus the length + * of the packet header plus the snapshot length. + */ + fp->bufsize = sizeof(struct rpcap_header) + sizeof(struct rpcap_pkthdr) + fp->snapshot; + + fp->buffer = (u_char *)malloc(fp->bufsize); + if (fp->buffer == NULL) + { + pcapint_fmt_errmsg_for_errno(fp->errbuf, PCAP_ERRBUF_SIZE, + errno, "malloc"); + goto error; + } + + /* + * The buffer is currently empty. + */ + fp->bp = fp->buffer; + fp->cc = 0; + + /* Discard the rest of the message. */ + if (rpcap_discard(pr->rmt_sockctrl, pr->ctrl_ssl, plen, fp->errbuf) == -1) + goto error_nodiscard; + + /* + * In case the user does not want to capture RPCAP packets, let's update the filter + * We have to update it here (instead of sending it into the 'StartCapture' message + * because when we generate the 'start capture' we do not know (yet) all the ports + * we're currently using. + */ + if (pr->rmt_flags & PCAP_OPENFLAG_NOCAPTURE_RPCAP) + { + struct bpf_program fcode; + + if (pcap_createfilter_norpcappkt(fp, &fcode) == -1) + goto error; + + /* We cannot use 'pcap_setfilter_rpcap' because formally the capture has not been started yet */ + /* (the 'pr->rmt_capstarted' variable will be updated some lines below) */ + if (pcap_updatefilter_remote(fp, &fcode) == -1) + goto error; + + pcap_freecode(&fcode); + } + + pr->rmt_capstarted = 1; + return 0; + +error: + /* + * When the connection has been established, we have to close it. So, at the + * beginning of this function, if an error occur we return immediately with + * a return NULL; when the connection is established, we have to come here + * ('goto error;') in order to close everything properly. + */ + + /* + * Discard the rest of the message. + * We already reported an error; if this gets an error, just + * drive on. + */ + (void)rpcap_discard(pr->rmt_sockctrl, pr->ctrl_ssl, plen, NULL); + +error_nodiscard: +#ifdef HAVE_OPENSSL + if (pr->data_ssl) + { + // Finish using the SSL handle for the data socket. + // This must be done *before* the socket is closed. + ssl_finish(pr->data_ssl); + pr->data_ssl = NULL; + } +#endif + + /* we can be here because sockdata said 'error' */ + if ((sockdata != 0) && (sockdata != INVALID_SOCKET)) + sock_close(sockdata, NULL, 0); + + if (!active) + { +#ifdef HAVE_OPENSSL + if (pr->ctrl_ssl) + { + // Finish using the SSL handle for the control socket. + // This must be done *before* the socket is closed. + ssl_finish(pr->ctrl_ssl); + pr->ctrl_ssl = NULL; + } +#endif + sock_close(pr->rmt_sockctrl, NULL, 0); + } + + if (addrinfo != NULL) + freeaddrinfo(addrinfo); + + /* + * We do not have to call pcap_close() here, because this function is always called + * by the user in case something bad happens + */ +#if 0 + if (fp) + { + pcap_close(fp); + fp= NULL; + } +#endif + + return -1; +} + +/* + * This function takes a bpf program and sends it to the other host. + * + * This function can be called in two cases: + * - pcap_startcapture_remote() is called (we have to send the filter + * along with the 'start capture' command) + * - we want to update the filter during a capture (i.e. pcap_setfilter() + * after the capture has been started) + * + * This function serializes the filter into the sending buffer ('sendbuf', + * passed as a parameter) and return back. It does not send anything on + * the network. + * + * \param fp: the pcap_t descriptor of the device currently opened. + * + * \param sendbuf: the buffer on which the serialized data has to copied. + * + * \param sendbufidx: it is used to return the amount of bytes copied into the buffer. + * + * \param prog: the bpf program we have to copy. + * + * \return '0' if everything is fine, '-1' otherwise. The error message (if one) + * is returned into the 'errbuf' field of the pcap_t structure. + */ +static int pcap_pack_bpffilter(pcap_t *fp, char *sendbuf, int *sendbufidx, struct bpf_program *prog) +{ + struct rpcap_filter *filter; + struct rpcap_filterbpf_insn *insn; + struct bpf_insn *bf_insn; + struct bpf_program fake_prog; /* To be used just in case the user forgot to set a filter */ + unsigned int i; + + if (prog->bf_len == 0) /* No filters have been specified; so, let's apply a "fake" filter */ + { + if (pcap_compile(fp, &fake_prog, NULL /* buffer */, 1, 0) == -1) + return -1; + + prog = &fake_prog; + } + + filter = (struct rpcap_filter *) sendbuf; + + if (sock_bufferize(NULL, sizeof(struct rpcap_filter), NULL, sendbufidx, + RPCAP_NETBUF_SIZE, SOCKBUF_CHECKONLY, fp->errbuf, PCAP_ERRBUF_SIZE)) + return -1; + + filter->filtertype = htons(RPCAP_UPDATEFILTER_BPF); + filter->nitems = htonl((int32)prog->bf_len); + + if (sock_bufferize(NULL, prog->bf_len * sizeof(struct rpcap_filterbpf_insn), + NULL, sendbufidx, RPCAP_NETBUF_SIZE, SOCKBUF_CHECKONLY, fp->errbuf, PCAP_ERRBUF_SIZE)) + return -1; + + insn = (struct rpcap_filterbpf_insn *) (filter + 1); + bf_insn = prog->bf_insns; + + for (i = 0; i < prog->bf_len; i++) + { + insn->code = htons(bf_insn->code); + insn->jf = bf_insn->jf; + insn->jt = bf_insn->jt; + insn->k = htonl(bf_insn->k); + + insn++; + bf_insn++; + } + + return 0; +} + +/* + * This function updates a filter on a remote host. + * + * It is called when the user wants to update a filter. + * In case we're capturing from the network, it sends the filter to our + * peer. + * This function is *not* called automatically when the user calls + * pcap_setfilter(). + * There will be two cases: + * - the capture has been started: in this case, pcap_setfilter_rpcap() + * calls pcap_updatefilter_remote() + * - the capture has not started yet: in this case, pcap_setfilter_rpcap() + * stores the filter into the pcap_t structure, and then the filter is + * sent with pcap_startcap(). + * + * WARNING This function *does not* clear the packet currently into the + * buffers. Therefore, the user has to expect to receive some packets + * that are related to the previous filter. If you want to discard all + * the packets before applying a new filter, you have to close the + * current capture session and start a new one. + * + * XXX - we really should have pcap_setfilter() always discard packets + * received with the old filter, and have a separate pcap_setfilter_noflush() + * function that doesn't discard any packets. + */ +static int pcap_updatefilter_remote(pcap_t *fp, struct bpf_program *prog) +{ + struct pcap_rpcap *pr = fp->priv; /* structure used when doing a remote live capture */ + char sendbuf[RPCAP_NETBUF_SIZE]; /* temporary buffer in which data to be sent is buffered */ + int sendbufidx = 0; /* index which keeps the number of bytes currently buffered */ + struct rpcap_header header; /* To keep the reply message */ + + if (sock_bufferize(NULL, sizeof(struct rpcap_header), NULL, &sendbufidx, + RPCAP_NETBUF_SIZE, SOCKBUF_CHECKONLY, fp->errbuf, PCAP_ERRBUF_SIZE)) + return -1; + + rpcap_createhdr((struct rpcap_header *) sendbuf, + pr->protocol_version, RPCAP_MSG_UPDATEFILTER_REQ, 0, + sizeof(struct rpcap_filter) + prog->bf_len * sizeof(struct rpcap_filterbpf_insn)); + + if (pcap_pack_bpffilter(fp, &sendbuf[sendbufidx], &sendbufidx, prog)) + return -1; + + if (sock_send(pr->rmt_sockctrl, pr->ctrl_ssl, sendbuf, sendbufidx, fp->errbuf, + PCAP_ERRBUF_SIZE) < 0) + return -1; + + /* Receive and process the reply message header. */ + if (rpcap_process_msg_header(pr->rmt_sockctrl, pr->ctrl_ssl, pr->protocol_version, + RPCAP_MSG_UPDATEFILTER_REQ, &header, fp->errbuf) == -1) + return -1; + + /* + * It shouldn't have any contents; discard it if it does. + */ + if (rpcap_discard(pr->rmt_sockctrl, pr->ctrl_ssl, header.plen, fp->errbuf) == -1) + return -1; + + return 0; +} + +static void +pcap_save_current_filter_rpcap(pcap_t *fp, const char *filter) +{ + struct pcap_rpcap *pr = fp->priv; /* structure used when doing a remote live capture */ + + /* + * Check if: + * - We are on an remote capture + * - we do not want to capture RPCAP traffic + * + * If so, we have to save the current filter, because we have to + * add some piece of stuff later + */ + if (pr->rmt_clientside && + (pr->rmt_flags & PCAP_OPENFLAG_NOCAPTURE_RPCAP)) + { + if (pr->currentfilter) + free(pr->currentfilter); + + if (filter == NULL) + filter = ""; + + pr->currentfilter = strdup(filter); + } +} + +/* + * This function sends a filter to a remote host. + * + * This function is called when the user wants to set a filter. + * It sends the filter to our peer. + * This function is called automatically when the user calls pcap_setfilter(). + * + * Parameters and return values are exactly the same of pcap_setfilter(). + */ +static int pcap_setfilter_rpcap(pcap_t *fp, struct bpf_program *prog) +{ + struct pcap_rpcap *pr = fp->priv; /* structure used when doing a remote live capture */ + + if (!pr->rmt_capstarted) + { + /* copy filter into the pcap_t structure */ + if (pcapint_install_bpf_program(fp, prog) == -1) + return -1; + return 0; + } + + /* we have to update a filter during run-time */ + if (pcap_updatefilter_remote(fp, prog)) + return -1; + + return 0; +} + +/* + * This function updates the current filter in order not to capture rpcap + * packets. + * + * This function is called *only* when the user wants exclude RPCAP packets + * related to the current session from the captured packets. + * + * \return '0' if everything is fine, '-1' otherwise. The error message (if one) + * is returned into the 'errbuf' field of the pcap_t structure. + */ +static int pcap_createfilter_norpcappkt(pcap_t *fp, struct bpf_program *prog) +{ + struct pcap_rpcap *pr = fp->priv; /* structure used when doing a remote live capture */ + int RetVal = 0; + + /* We do not want to capture our RPCAP traffic. So, let's update the filter */ + if (pr->rmt_flags & PCAP_OPENFLAG_NOCAPTURE_RPCAP) + { + struct sockaddr_storage saddr; /* temp, needed to retrieve the network data port chosen on the local machine */ + socklen_t saddrlen; /* temp, needed to retrieve the network data port chosen on the local machine */ + char myaddress[128]; + char myctrlport[128]; + char mydataport[128]; + char peeraddress[128]; + char peerctrlport[128]; + char *newfilter; + + /* Get the name/port of our peer */ + saddrlen = sizeof(struct sockaddr_storage); + if (getpeername(pr->rmt_sockctrl, (struct sockaddr *) &saddr, &saddrlen) == -1) + { + sock_geterrmsg(fp->errbuf, PCAP_ERRBUF_SIZE, + "getpeername() failed"); + return -1; + } + + if (getnameinfo((struct sockaddr *) &saddr, saddrlen, peeraddress, + sizeof(peeraddress), peerctrlport, sizeof(peerctrlport), NI_NUMERICHOST | NI_NUMERICSERV)) + { + sock_geterrmsg(fp->errbuf, PCAP_ERRBUF_SIZE, + "getnameinfo() failed"); + return -1; + } + + /* We cannot check the data port, because this is available only in case of TCP sockets */ + /* Get the name/port of the current host */ + if (getsockname(pr->rmt_sockctrl, (struct sockaddr *) &saddr, &saddrlen) == -1) + { + sock_geterrmsg(fp->errbuf, PCAP_ERRBUF_SIZE, + "getsockname() failed"); + return -1; + } + + /* Get the local port the system picked up */ + if (getnameinfo((struct sockaddr *) &saddr, saddrlen, myaddress, + sizeof(myaddress), myctrlport, sizeof(myctrlport), NI_NUMERICHOST | NI_NUMERICSERV)) + { + sock_geterrmsg(fp->errbuf, PCAP_ERRBUF_SIZE, + "getnameinfo() failed"); + return -1; + } + + /* Let's now check the data port */ + if (getsockname(pr->rmt_sockdata, (struct sockaddr *) &saddr, &saddrlen) == -1) + { + sock_geterrmsg(fp->errbuf, PCAP_ERRBUF_SIZE, + "getsockname() failed"); + return -1; + } + + /* Get the local port the system picked up */ + if (getnameinfo((struct sockaddr *) &saddr, saddrlen, NULL, 0, mydataport, sizeof(mydataport), NI_NUMERICSERV)) + { + sock_geterrmsg(fp->errbuf, PCAP_ERRBUF_SIZE, + "getnameinfo() failed"); + return -1; + } + + if (pr->currentfilter && pr->currentfilter[0] != '\0') + { + /* + * We have a current filter; add items to it to + * filter out this rpcap session. + */ + if (pcapint_asprintf(&newfilter, + "(%s) and not (host %s and host %s and port %s and port %s) and not (host %s and host %s and port %s)", + pr->currentfilter, myaddress, peeraddress, + myctrlport, peerctrlport, myaddress, peeraddress, + mydataport) == -1) + { + /* Failed. */ + snprintf(fp->errbuf, PCAP_ERRBUF_SIZE, + "Can't allocate memory for new filter"); + return -1; + } + } + else + { + /* + * We have no current filter; construct a filter to + * filter out this rpcap session. + */ + if (pcapint_asprintf(&newfilter, + "not (host %s and host %s and port %s and port %s) and not (host %s and host %s and port %s)", + myaddress, peeraddress, myctrlport, peerctrlport, + myaddress, peeraddress, mydataport) == -1) + { + /* Failed. */ + snprintf(fp->errbuf, PCAP_ERRBUF_SIZE, + "Can't allocate memory for new filter"); + return -1; + } + } + + /* + * This is only an hack to prevent the save_current_filter + * routine, which will be called when we call pcap_compile(), + * from saving the modified filter. + */ + pr->rmt_clientside = 0; + + if (pcap_compile(fp, prog, newfilter, 1, 0) == -1) + RetVal = -1; + + /* Undo the hack. */ + pr->rmt_clientside = 1; + + free(newfilter); + } + + return RetVal; +} + +/* + * This function sets sampling parameters in the remote host. + * + * It is called when the user wants to set activate sampling on the + * remote host. + * + * Sampling parameters are defined into the 'pcap_t' structure. + * + * \param p: the pcap_t descriptor of the device currently opened. + * + * \return '0' if everything is OK, '-1' is something goes wrong. The + * error message is returned in the 'errbuf' member of the pcap_t structure. + */ +static int pcap_setsampling_remote(pcap_t *fp) +{ + struct pcap_rpcap *pr = fp->priv; /* structure used when doing a remote live capture */ + char sendbuf[RPCAP_NETBUF_SIZE];/* temporary buffer in which data to be sent is buffered */ + int sendbufidx = 0; /* index which keeps the number of bytes currently buffered */ + struct rpcap_header header; /* To keep the reply message */ + struct rpcap_sampling *sampling_pars; /* Structure that is needed to send sampling parameters to the remote host */ + + /* If no sampling is requested, return 'ok' */ + if (fp->rmt_samp.method == PCAP_SAMP_NOSAMP) + return 0; + + /* + * Check for sampling parameters that don't fit in a message. + * We'll let the server complain about invalid parameters + * that do fit into the message. + */ + if (fp->rmt_samp.method < 0 || fp->rmt_samp.method > 255) { + snprintf(fp->errbuf, PCAP_ERRBUF_SIZE, + "Invalid sampling method %d", fp->rmt_samp.method); + return -1; + } + if (fp->rmt_samp.value < 0 || fp->rmt_samp.value > 65535) { + snprintf(fp->errbuf, PCAP_ERRBUF_SIZE, + "Invalid sampling value %d", fp->rmt_samp.value); + return -1; + } + + if (sock_bufferize(NULL, sizeof(struct rpcap_header), NULL, + &sendbufidx, RPCAP_NETBUF_SIZE, SOCKBUF_CHECKONLY, fp->errbuf, PCAP_ERRBUF_SIZE)) + return -1; + + rpcap_createhdr((struct rpcap_header *) sendbuf, + pr->protocol_version, RPCAP_MSG_SETSAMPLING_REQ, 0, + sizeof(struct rpcap_sampling)); + + /* Fill the structure needed to open an adapter remotely */ + sampling_pars = (struct rpcap_sampling *) &sendbuf[sendbufidx]; + + if (sock_bufferize(NULL, sizeof(struct rpcap_sampling), NULL, + &sendbufidx, RPCAP_NETBUF_SIZE, SOCKBUF_CHECKONLY, fp->errbuf, PCAP_ERRBUF_SIZE)) + return -1; + + memset(sampling_pars, 0, sizeof(struct rpcap_sampling)); + + sampling_pars->method = (uint8)fp->rmt_samp.method; + sampling_pars->value = (uint16)htonl(fp->rmt_samp.value); + + if (sock_send(pr->rmt_sockctrl, pr->ctrl_ssl, sendbuf, sendbufidx, fp->errbuf, + PCAP_ERRBUF_SIZE) < 0) + return -1; + + /* Receive and process the reply message header. */ + if (rpcap_process_msg_header(pr->rmt_sockctrl, pr->ctrl_ssl, pr->protocol_version, + RPCAP_MSG_SETSAMPLING_REQ, &header, fp->errbuf) == -1) + return -1; + + /* + * It shouldn't have any contents; discard it if it does. + */ + if (rpcap_discard(pr->rmt_sockctrl, pr->ctrl_ssl, header.plen, fp->errbuf) == -1) + return -1; + + return 0; +} + +/********************************************************* + * * + * Miscellaneous functions * + * * + *********************************************************/ + +/* + * This function performs authentication and protocol version + * negotiation. It is required in order to open the connection + * with the other end party. + * + * It sends authentication parameters on the control socket and + * reads the reply. If the reply is a success indication, it + * checks whether the reply includes minimum and maximum supported + * versions from the server; if not, it assumes both are 0, as + * that means it's an older server that doesn't return supported + * version numbers in authentication replies, so it only supports + * version 0. It then tries to determine the maximum version + * supported both by us and by the server. If it can find such a + * version, it sets us up to use that version; otherwise, it fails, + * indicating that there is no version supported by us and by the + * server. + * + * \param sock: the socket we are currently using. + * + * \param ver: pointer to variable to which to set the protocol version + * number we selected. + * + * \param byte_swapped: pointer to variable to which to set 1 if the + * byte order the server says it has is byte-swapped from ours, 0 + * otherwise (whether it's the same as ours or is unknown). + * + * \param auth: authentication parameters that have to be sent. + * + * \param errbuf: a pointer to a user-allocated buffer (of size + * PCAP_ERRBUF_SIZE) that will contain the error message (in case there + * is one). It could be a network problem or the fact that the authorization + * failed. + * + * \return '0' if everything is fine, '-1' for an error. For errors, + * an error message string is returned in the 'errbuf' variable. + */ +static int rpcap_doauth(PCAP_SOCKET sockctrl, SSL *ssl, uint8 *ver, + int *byte_swapped, struct pcap_rmtauth *auth, char *errbuf) +{ + char sendbuf[RPCAP_NETBUF_SIZE]; /* temporary buffer in which data that has to be sent is buffered */ + int sendbufidx = 0; /* index which keeps the number of bytes currently buffered */ + uint16 length; /* length of the payload of this message */ + struct rpcap_auth *rpauth; + uint16 auth_type; + struct rpcap_header header; + size_t str_length; + uint32 plen; + struct rpcap_authreply authreply; /* authentication reply message */ + uint8 ourvers; + int has_byte_order; /* The server sent its version of the byte-order magic number */ + u_int their_byte_order_magic; /* Here's what it is */ + + if (auth) + { + switch (auth->type) + { + case RPCAP_RMTAUTH_NULL: + length = sizeof(struct rpcap_auth); + break; + + case RPCAP_RMTAUTH_PWD: + length = sizeof(struct rpcap_auth); + if (auth->username) + { + str_length = strlen(auth->username); + if (str_length > 65535) + { + snprintf(errbuf, PCAP_ERRBUF_SIZE, "User name is too long (> 65535 bytes)"); + return -1; + } + length += (uint16)str_length; + } + if (auth->password) + { + str_length = strlen(auth->password); + if (str_length > 65535) + { + snprintf(errbuf, PCAP_ERRBUF_SIZE, "Password is too long (> 65535 bytes)"); + return -1; + } + length += (uint16)str_length; + } + break; + + default: + snprintf(errbuf, PCAP_ERRBUF_SIZE, "Authentication type not recognized."); + return -1; + } + + auth_type = (uint16)auth->type; + } + else + { + auth_type = RPCAP_RMTAUTH_NULL; + length = sizeof(struct rpcap_auth); + } + + if (sock_bufferize(NULL, sizeof(struct rpcap_header), NULL, + &sendbufidx, RPCAP_NETBUF_SIZE, SOCKBUF_CHECKONLY, errbuf, PCAP_ERRBUF_SIZE)) + return -1; + + rpcap_createhdr((struct rpcap_header *) sendbuf, 0, + RPCAP_MSG_AUTH_REQ, 0, length); + + rpauth = (struct rpcap_auth *) &sendbuf[sendbufidx]; + + if (sock_bufferize(NULL, sizeof(struct rpcap_auth), NULL, + &sendbufidx, RPCAP_NETBUF_SIZE, SOCKBUF_CHECKONLY, errbuf, PCAP_ERRBUF_SIZE)) + return -1; + + memset(rpauth, 0, sizeof(struct rpcap_auth)); + + rpauth->type = htons(auth_type); + + if (auth_type == RPCAP_RMTAUTH_PWD) + { + if (auth->username) + rpauth->slen1 = (uint16)strlen(auth->username); + else + rpauth->slen1 = 0; + + if (sock_bufferize(auth->username, rpauth->slen1, sendbuf, + &sendbufidx, RPCAP_NETBUF_SIZE, SOCKBUF_BUFFERIZE, errbuf, PCAP_ERRBUF_SIZE)) + return -1; + + if (auth->password) + rpauth->slen2 = (uint16)strlen(auth->password); + else + rpauth->slen2 = 0; + + if (sock_bufferize(auth->password, rpauth->slen2, sendbuf, + &sendbufidx, RPCAP_NETBUF_SIZE, SOCKBUF_BUFFERIZE, errbuf, PCAP_ERRBUF_SIZE)) + return -1; + + rpauth->slen1 = htons(rpauth->slen1); + rpauth->slen2 = htons(rpauth->slen2); + } + + if (sock_send(sockctrl, ssl, sendbuf, sendbufidx, errbuf, + PCAP_ERRBUF_SIZE) < 0) + return -1; + + /* Receive and process the reply message header */ + if (rpcap_process_msg_header(sockctrl, ssl, 0, RPCAP_MSG_AUTH_REQ, + &header, errbuf) == -1) + return -1; + + /* + * OK, it's an authentication reply, so we're logged in. + * + * Did it send any additional information? + */ + plen = header.plen; + if (plen != 0) + { + size_t reply_len; + + /* Yes - is it big enough to include version information? */ + if (plen < sizeof(struct rpcap_authreply_old)) + { + /* No - discard it and fail. */ + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "Authentication reply from server is too short"); + (void)rpcap_discard(sockctrl, ssl, plen, NULL); + return -1; + } + + /* Yes - does it include server byte order information? */ + if (plen == sizeof(struct rpcap_authreply_old)) + { + /* No - just read the version information */ + has_byte_order = 0; + reply_len = sizeof(struct rpcap_authreply_old); + } + else if (plen >= sizeof(struct rpcap_authreply_old)) + { + /* Yes - read it all. */ + has_byte_order = 1; + reply_len = sizeof(struct rpcap_authreply); + } + else + { + /* + * Too long for old reply, too short for new reply. + * Discard it and fail. + */ + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "Authentication reply from server is too short"); + (void)rpcap_discard(sockctrl, ssl, plen, NULL); + return -1; + } + + /* Read the reply body */ + if (rpcap_recv(sockctrl, ssl, (char *)&authreply, + reply_len, &plen, errbuf) == -1) + { + (void)rpcap_discard(sockctrl, ssl, plen, NULL); + return -1; + } + + /* Discard the rest of the message, if there is any. */ + if (rpcap_discard(sockctrl, ssl, plen, errbuf) == -1) + return -1; + + /* + * Check the minimum and maximum versions for sanity; + * the minimum must be <= the maximum. + */ + if (authreply.minvers > authreply.maxvers) + { + /* + * Bogus - give up on this server. + */ + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "The server's minimum supported protocol version is greater than its maximum supported protocol version"); + return -1; + } + + if (has_byte_order) + { + their_byte_order_magic = authreply.byte_order_magic; + } + else + { + /* + * The server didn't tell us what its byte + * order is; assume it's ours. + */ + their_byte_order_magic = RPCAP_BYTE_ORDER_MAGIC; + } + } + else + { + /* No - it supports only version 0. */ + authreply.minvers = 0; + authreply.maxvers = 0; + + /* + * And it didn't tell us what its byte order is; assume + * it's ours. + */ + has_byte_order = 0; + their_byte_order_magic = RPCAP_BYTE_ORDER_MAGIC; + } + + /* + * OK, let's start with the maximum version the server supports. + */ + ourvers = authreply.maxvers; + +#if RPCAP_MIN_VERSION != 0 + /* + * If that's less than the minimum version we support, we + * can't communicate. + */ + if (ourvers < RPCAP_MIN_VERSION) + goto novers; +#endif + + /* + * If that's greater than the maximum version we support, + * choose the maximum version we support. + */ + if (ourvers > RPCAP_MAX_VERSION) + { + ourvers = RPCAP_MAX_VERSION; + + /* + * If that's less than the minimum version they + * support, we can't communicate. + */ + if (ourvers < authreply.minvers) + goto novers; + } + + /* + * Is the server byte order the opposite of ours? + */ + if (their_byte_order_magic == RPCAP_BYTE_ORDER_MAGIC) + { + /* No, it's the same. */ + *byte_swapped = 0; + } + else if (their_byte_order_magic == RPCAP_BYTE_ORDER_MAGIC_SWAPPED) + { + /* Yes, it's the opposite of ours. */ + *byte_swapped = 1; + } + else + { + /* They sent us something bogus. */ + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "The server did not send us a valid byte order value"); + return -1; + } + + *ver = ourvers; + return 0; + +novers: + /* + * There is no version we both support; that is a fatal error. + */ + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "The server doesn't support any protocol version that we support"); + return -1; +} + +/* We don't currently support non-blocking mode. */ +static int +pcap_getnonblock_rpcap(pcap_t *p) +{ + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "Non-blocking mode isn't supported for capturing remotely with rpcap"); + return (-1); +} + +static int +pcap_setnonblock_rpcap(pcap_t *p, int nonblock _U_) +{ + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "Non-blocking mode isn't supported for capturing remotely with rpcap"); + return (-1); +} + +static int +rpcap_setup_session(const char *source, struct pcap_rmtauth *auth, + int *activep, PCAP_SOCKET *sockctrlp, uint8 *uses_sslp, SSL **sslp, + int rmt_flags, uint8 *protocol_versionp, int *byte_swappedp, + char *host, char *port, char *iface, char *errbuf) +{ + int type; + struct activehosts *activeconn; /* active connection, if there is one */ + int error; /* 1 if rpcap_remoteact_getsock got an error */ + + /* + * Determine the type of the source (NULL, file, local, remote). + * You must have a valid source string even if we're in active mode, + * because otherwise the call to the following function will fail. + */ + if (pcapint_parsesrcstr_ex(source, &type, host, port, iface, uses_sslp, + errbuf) == -1) + return -1; + + /* + * It must be remote. + */ + if (type != PCAP_SRC_IFREMOTE) + { + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "Non-remote interface passed to remote capture routine"); + return -1; + } + + /* + * We don't yet support DTLS, so if the user asks for a TLS + * connection and asks for data packets to be sent over UDP, + * we have to give up. + */ + if (*uses_sslp && (rmt_flags & PCAP_OPENFLAG_DATATX_UDP)) + { + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "TLS not supported with UDP forward of remote packets"); + return -1; + } + + /* Warning: this call can be the first one called by the user. */ + /* For this reason, we have to initialize the Winsock support. */ + if (sock_init(errbuf, PCAP_ERRBUF_SIZE) == -1) + return -1; + + /* Check for active mode */ + activeconn = rpcap_remoteact_getsock(host, &error, errbuf); + if (activeconn != NULL) + { + *activep = 1; + *sockctrlp = activeconn->sockctrl; + *sslp = activeconn->ssl; + *protocol_versionp = activeconn->protocol_version; + *byte_swappedp = activeconn->byte_swapped; + } + else + { + *activep = 0; + struct addrinfo hints; /* temp variable needed to resolve hostnames into to socket representation */ + struct addrinfo *addrinfo; /* temp variable needed to resolve hostnames into to socket representation */ + + if (error) + { + /* + * Call failed. + */ + return -1; + } + + /* + * We're not in active mode; let's try to open a new + * control connection. + */ + memset(&hints, 0, sizeof(struct addrinfo)); + hints.ai_family = PF_UNSPEC; + hints.ai_socktype = SOCK_STREAM; + + if (port[0] == 0) + { + /* the user chose not to specify the port */ + addrinfo = sock_initaddress(host, RPCAP_DEFAULT_NETPORT, + &hints, errbuf, PCAP_ERRBUF_SIZE); + } + else + { + addrinfo = sock_initaddress(host, port, &hints, + errbuf, PCAP_ERRBUF_SIZE); + } + if (addrinfo == NULL) + return -1; + + if ((*sockctrlp = sock_open(host, addrinfo, SOCKOPEN_CLIENT, 0, + errbuf, PCAP_ERRBUF_SIZE)) == INVALID_SOCKET) + { + freeaddrinfo(addrinfo); + return -1; + } + + /* addrinfo is no longer used */ + freeaddrinfo(addrinfo); + addrinfo = NULL; + + if (*uses_sslp) + { +#ifdef HAVE_OPENSSL + *sslp = ssl_promotion(0, *sockctrlp, errbuf, + PCAP_ERRBUF_SIZE); + if (!*sslp) + { + sock_close(*sockctrlp, NULL, 0); + return -1; + } +#else + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "No TLS support"); + sock_close(*sockctrlp, NULL, 0); + return -1; +#endif + } + + if (rpcap_doauth(*sockctrlp, *sslp, protocol_versionp, + byte_swappedp, auth, errbuf) == -1) + { +#ifdef HAVE_OPENSSL + if (*sslp) + { + // Finish using the SSL handle for the socket. + // This must be done *before* the socket is + // closed. + ssl_finish(*sslp); + } +#endif + sock_close(*sockctrlp, NULL, 0); + return -1; + } + } + return 0; +} + +/* + * This function opens a remote adapter by opening an RPCAP connection and + * so on. + * + * It does the job of pcap_open_live() for a remote interface; it's called + * by pcap_open() for remote interfaces. + * + * We do not start the capture until pcap_startcapture_remote() is called. + * + * This is because, when doing a remote capture, we cannot start capturing + * data as soon as the 'open adapter' command is sent. Suppose the remote + * adapter is already overloaded; if we start a capture (which, by default, + * has a NULL filter) the new traffic can saturate the network. + * + * Instead, we want to "open" the adapter, then send a "start capture" + * command only when we're ready to start the capture. + * This function does this job: it sends an "open adapter" command + * (according to the RPCAP protocol), but it does not start the capture. + * + * Since the other libpcap functions do not share this way of life, we + * have to do some dirty things in order to make everything work. + * + * \param source: see pcap_open(). + * \param snaplen: see pcap_open(). + * \param flags: see pcap_open(). + * \param read_timeout: see pcap_open(). + * \param auth: see pcap_open(). + * \param errbuf: see pcap_open(). + * + * \return a pcap_t pointer in case of success, NULL otherwise. In case of + * success, the pcap_t pointer can be used as a parameter to the following + * calls (pcap_compile() and so on). In case of problems, errbuf contains + * a text explanation of error. + * + * WARNING: In case we call pcap_compile() and the capture has not yet + * been started, the filter will be saved into the pcap_t structure, + * and it will be sent to the other host later (when + * pcap_startcapture_remote() is called). + */ +pcap_t *pcap_open_rpcap(const char *source, int snaplen, int flags, int read_timeout, struct pcap_rmtauth *auth, char *errbuf) +{ + pcap_t *fp; + char *source_str; + struct pcap_rpcap *pr; /* structure used when doing a remote live capture */ + char host[PCAP_BUF_SIZE], ctrlport[PCAP_BUF_SIZE], iface[PCAP_BUF_SIZE]; + PCAP_SOCKET sockctrl; + SSL *ssl = NULL; + uint8 protocol_version; /* negotiated protocol version */ + int byte_swapped; /* server is known to be byte-swapped */ + int active; + uint32 plen; + char sendbuf[RPCAP_NETBUF_SIZE]; /* temporary buffer in which data to be sent is buffered */ + int sendbufidx = 0; /* index which keeps the number of bytes currently buffered */ + + /* RPCAP-related variables */ + struct rpcap_header header; /* header of the RPCAP packet */ + struct rpcap_openreply openreply; /* open reply message */ + + fp = PCAP_CREATE_COMMON(errbuf, struct pcap_rpcap); + if (fp == NULL) + { + return NULL; + } + source_str = strdup(source); + if (source_str == NULL) { + pcapint_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, + errno, "malloc"); + return NULL; + } + + /* + * Turn a negative snapshot value (invalid), a snapshot value of + * 0 (unspecified), or a value bigger than the normal maximum + * value, into the maximum allowed value. + * + * If some application really *needs* a bigger snapshot + * length, we should just increase MAXIMUM_SNAPLEN. + * + * XXX - should we leave this up to the remote server to + * do? + */ + if (snaplen <= 0 || snaplen > MAXIMUM_SNAPLEN) + snaplen = MAXIMUM_SNAPLEN; + + fp->opt.device = source_str; + fp->snapshot = snaplen; + fp->opt.timeout = read_timeout; + pr = fp->priv; + pr->rmt_flags = flags; + + /* + * Attempt to set up the session with the server. + */ + if (rpcap_setup_session(fp->opt.device, auth, &active, &sockctrl, + &pr->uses_ssl, &ssl, flags, &protocol_version, &byte_swapped, + host, ctrlport, iface, errbuf) == -1) + { + /* Session setup failed. */ + pcap_close(fp); + return NULL; + } + + /* All good so far, save the ssl handler */ + ssl_main = ssl; + + /* + * Now it's time to start playing with the RPCAP protocol + * RPCAP open command: create the request message + */ + if (sock_bufferize(NULL, sizeof(struct rpcap_header), NULL, + &sendbufidx, RPCAP_NETBUF_SIZE, SOCKBUF_CHECKONLY, errbuf, PCAP_ERRBUF_SIZE)) + goto error_nodiscard; + + rpcap_createhdr((struct rpcap_header *) sendbuf, protocol_version, + RPCAP_MSG_OPEN_REQ, 0, (uint32) strlen(iface)); + + if (sock_bufferize(iface, (int) strlen(iface), sendbuf, &sendbufidx, + RPCAP_NETBUF_SIZE, SOCKBUF_BUFFERIZE, errbuf, PCAP_ERRBUF_SIZE)) + goto error_nodiscard; + + if (sock_send(sockctrl, ssl, sendbuf, sendbufidx, errbuf, + PCAP_ERRBUF_SIZE) < 0) + goto error_nodiscard; + + /* Receive and process the reply message header. */ + if (rpcap_process_msg_header(sockctrl, ssl, protocol_version, + RPCAP_MSG_OPEN_REQ, &header, errbuf) == -1) + goto error_nodiscard; + plen = header.plen; + + /* Read the reply body */ + if (rpcap_recv(sockctrl, ssl, (char *)&openreply, + sizeof(struct rpcap_openreply), &plen, errbuf) == -1) + goto error; + + /* Discard the rest of the message, if there is any. */ + if (rpcap_discard(sockctrl, ssl, plen, errbuf) == -1) + goto error_nodiscard; + + /* Set proper fields into the pcap_t struct */ + fp->linktype = ntohl(openreply.linktype); + pr->rmt_sockctrl = sockctrl; + pr->ctrl_ssl = ssl; + pr->protocol_version = protocol_version; + pr->byte_swapped = byte_swapped; + pr->rmt_clientside = 1; + + /* This code is duplicated from the end of this function */ + fp->read_op = pcap_read_rpcap; + fp->save_current_filter_op = pcap_save_current_filter_rpcap; + fp->setfilter_op = pcap_setfilter_rpcap; + fp->getnonblock_op = pcap_getnonblock_rpcap; + fp->setnonblock_op = pcap_setnonblock_rpcap; + fp->stats_op = pcap_stats_rpcap; +#ifdef _WIN32 + fp->stats_ex_op = pcap_stats_ex_rpcap; +#endif + fp->cleanup_op = pcap_cleanup_rpcap; + + fp->activated = 1; + return fp; + +error: + /* + * When the connection has been established, we have to close it. So, at the + * beginning of this function, if an error occur we return immediately with + * a return NULL; when the connection is established, we have to come here + * ('goto error;') in order to close everything properly. + */ + + /* + * Discard the rest of the message. + * We already reported an error; if this gets an error, just + * drive on. + */ + (void)rpcap_discard(sockctrl, pr->ctrl_ssl, plen, NULL); + +error_nodiscard: + if (!active) + { +#ifdef HAVE_OPENSSL + if (ssl) + { + // Finish using the SSL handle for the socket. + // This must be done *before* the socket is closed. + ssl_finish(ssl); + } +#endif + sock_close(sockctrl, NULL, 0); + } + + pcap_close(fp); + return NULL; +} + +/* String identifier to be used in the pcap_findalldevs_ex() */ +#define PCAP_TEXT_SOURCE_ADAPTER "Network adapter" +#define PCAP_TEXT_SOURCE_ADAPTER_LEN (sizeof PCAP_TEXT_SOURCE_ADAPTER - 1) +/* String identifier to be used in the pcap_findalldevs_ex() */ +#define PCAP_TEXT_SOURCE_ON_REMOTE_HOST "on remote node" +#define PCAP_TEXT_SOURCE_ON_REMOTE_HOST_LEN (sizeof PCAP_TEXT_SOURCE_ON_REMOTE_HOST - 1) + +static void +freeaddr(struct pcap_addr *addr) +{ + free(addr->addr); + free(addr->netmask); + free(addr->broadaddr); + free(addr->dstaddr); + free(addr); +} + +int +pcap_findalldevs_ex_remote(const char *source, struct pcap_rmtauth *auth, pcap_if_t **alldevs, char *errbuf) +{ + uint8 protocol_version; /* protocol version */ + int byte_swapped; /* Server byte order is swapped from ours */ + PCAP_SOCKET sockctrl; /* socket descriptor of the control connection */ + SSL *ssl = NULL; /* optional SSL handler for sockctrl */ + uint32 plen; + struct rpcap_header header; /* structure that keeps the general header of the rpcap protocol */ + int i, j; /* temp variables */ + int nif; /* Number of interfaces listed */ + int active; /* 'true' if we the other end-party is in active mode */ + uint8 uses_ssl; + char host[PCAP_BUF_SIZE], port[PCAP_BUF_SIZE]; + char tmpstring[PCAP_BUF_SIZE + 1]; /* Needed to convert names and descriptions from 'old' syntax to the 'new' one */ + pcap_if_t *lastdev; /* Last device in the pcap_if_t list */ + pcap_if_t *dev; /* Device we're adding to the pcap_if_t list */ + + /* List starts out empty. */ + (*alldevs) = NULL; + lastdev = NULL; + + /* + * Attempt to set up the session with the server. + */ + if (rpcap_setup_session(source, auth, &active, &sockctrl, &uses_ssl, + &ssl, 0, &protocol_version, &byte_swapped, host, port, NULL, + errbuf) == -1) + { + /* Session setup failed. */ + return -1; + } + + /* RPCAP findalldevs command */ + rpcap_createhdr(&header, protocol_version, RPCAP_MSG_FINDALLIF_REQ, + 0, 0); + + if (sock_send(sockctrl, ssl, (char *)&header, sizeof(struct rpcap_header), + errbuf, PCAP_ERRBUF_SIZE) < 0) + goto error_nodiscard; + + /* Receive and process the reply message header. */ + if (rpcap_process_msg_header(sockctrl, ssl, protocol_version, + RPCAP_MSG_FINDALLIF_REQ, &header, errbuf) == -1) + goto error_nodiscard; + + plen = header.plen; + + /* read the number of interfaces */ + nif = ntohs(header.value); + + /* loop until all interfaces have been received */ + for (i = 0; i < nif; i++) + { + struct rpcap_findalldevs_if findalldevs_if; + char tmpstring2[PCAP_BUF_SIZE + 1]; /* Needed to convert names and descriptions from 'old' syntax to the 'new' one */ + struct pcap_addr *addr, *prevaddr; + + tmpstring2[PCAP_BUF_SIZE] = 0; + + /* receive the findalldevs structure from remote host */ + if (rpcap_recv(sockctrl, ssl, (char *)&findalldevs_if, + sizeof(struct rpcap_findalldevs_if), &plen, errbuf) == -1) + goto error; + + findalldevs_if.namelen = ntohs(findalldevs_if.namelen); + findalldevs_if.desclen = ntohs(findalldevs_if.desclen); + findalldevs_if.naddr = ntohs(findalldevs_if.naddr); + + /* allocate the main structure */ + dev = (pcap_if_t *)malloc(sizeof(pcap_if_t)); + if (dev == NULL) + { + pcapint_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, + errno, "malloc() failed"); + goto error; + } + + /* Initialize the structure to 'zero' */ + memset(dev, 0, sizeof(pcap_if_t)); + + /* Append it to the list. */ + if (lastdev == NULL) + { + /* + * List is empty, so it's also the first device. + */ + *alldevs = dev; + } + else + { + /* + * Append after the last device. + */ + lastdev->next = dev; + } + /* It's now the last device. */ + lastdev = dev; + + /* allocate mem for name and description */ + if (findalldevs_if.namelen) + { + + if (findalldevs_if.namelen >= sizeof(tmpstring)) + { + snprintf(errbuf, PCAP_ERRBUF_SIZE, "Interface name too long"); + goto error; + } + + /* Retrieve adapter name */ + if (rpcap_recv(sockctrl, ssl, tmpstring, + findalldevs_if.namelen, &plen, errbuf) == -1) + goto error; + + tmpstring[findalldevs_if.namelen] = 0; + + /* Create the new device identifier */ + if (pcapint_createsrcstr_ex(tmpstring2, PCAP_SRC_IFREMOTE, + host, port, tmpstring, uses_ssl, errbuf) == -1) + goto error; + + dev->name = strdup(tmpstring2); + if (dev->name == NULL) + { + pcapint_fmt_errmsg_for_errno(errbuf, + PCAP_ERRBUF_SIZE, errno, "malloc() failed"); + goto error; + } + } + + if (findalldevs_if.desclen) + { + if (findalldevs_if.desclen >= sizeof(tmpstring)) + { + snprintf(errbuf, PCAP_ERRBUF_SIZE, "Interface description too long"); + goto error; + } + + /* Retrieve adapter description */ + if (rpcap_recv(sockctrl, ssl, tmpstring, + findalldevs_if.desclen, &plen, errbuf) == -1) + goto error; + + tmpstring[findalldevs_if.desclen] = 0; + + if (pcapint_asprintf(&dev->description, + "%s '%s' %s %s", PCAP_TEXT_SOURCE_ADAPTER, + tmpstring, PCAP_TEXT_SOURCE_ON_REMOTE_HOST, host) == -1) + { + pcapint_fmt_errmsg_for_errno(errbuf, + PCAP_ERRBUF_SIZE, errno, "malloc() failed"); + goto error; + } + } + + dev->flags = ntohl(findalldevs_if.flags); + + prevaddr = NULL; + /* loop until all addresses have been received */ + for (j = 0; j < findalldevs_if.naddr; j++) + { + struct rpcap_findalldevs_ifaddr ifaddr; + + /* Retrieve the interface addresses */ + if (rpcap_recv(sockctrl, ssl, (char *)&ifaddr, + sizeof(struct rpcap_findalldevs_ifaddr), + &plen, errbuf) == -1) + goto error; + + /* + * Deserialize all the address components. + */ + addr = (struct pcap_addr *) malloc(sizeof(struct pcap_addr)); + if (addr == NULL) + { + pcapint_fmt_errmsg_for_errno(errbuf, + PCAP_ERRBUF_SIZE, errno, "malloc() failed"); + goto error; + } + addr->next = NULL; + addr->addr = NULL; + addr->netmask = NULL; + addr->broadaddr = NULL; + addr->dstaddr = NULL; + + if (rpcap_deseraddr(&ifaddr.addr, &addr->addr, + errbuf) == -1) + { + freeaddr(addr); + goto error; + } + if (rpcap_deseraddr(&ifaddr.netmask, &addr->netmask, + errbuf) == -1) + { + freeaddr(addr); + goto error; + } + if (rpcap_deseraddr(&ifaddr.broadaddr, &addr->broadaddr, + errbuf) == -1) + { + freeaddr(addr); + goto error; + } + if (rpcap_deseraddr(&ifaddr.dstaddr, &addr->dstaddr, + errbuf) == -1) + { + freeaddr(addr); + goto error; + } + + if ((addr->addr == NULL) && (addr->netmask == NULL) && + (addr->broadaddr == NULL) && (addr->dstaddr == NULL)) + { + /* + * None of the addresses are IPv4 or IPv6 + * addresses, so throw this entry away. + */ + free(addr); + } + else + { + /* + * Add this entry to the list. + */ + if (prevaddr == NULL) + { + dev->addresses = addr; + } + else + { + prevaddr->next = addr; + } + prevaddr = addr; + } + } + } + + /* Discard the rest of the message. */ + if (rpcap_discard(sockctrl, ssl, plen, errbuf) == 1) + goto error_nodiscard; + + /* Control connection has to be closed only in case the remote machine is in passive mode */ + if (!active) + { + /* DO not send RPCAP_CLOSE, since we did not open a pcap_t; no need to free resources */ +#ifdef HAVE_OPENSSL + if (ssl) + { + // Finish using the SSL handle for the socket. + // This must be done *before* the socket is closed. + ssl_finish(ssl); + } +#endif + if (sock_close(sockctrl, errbuf, PCAP_ERRBUF_SIZE)) + return -1; + } + + /* To avoid inconsistencies in the number of sock_init() */ + sock_cleanup(); + + return 0; + +error: + /* + * In case there has been an error, I don't want to overwrite it with a new one + * if the following call fails. I want to return always the original error. + * + * Take care: this connection can already be closed when we try to close it. + * This happens because a previous error in the rpcapd, which requested to + * closed the connection. In that case, we already recognized that into the + * rpspck_isheaderok() and we already acknowledged the closing. + * In that sense, this call is useless here (however it is needed in case + * the client generates the error). + * + * Checks if all the data has been read; if not, discard the data in excess + */ + (void) rpcap_discard(sockctrl, ssl, plen, NULL); + +error_nodiscard: + /* Control connection has to be closed only in case the remote machine is in passive mode */ + if (!active) + { +#ifdef HAVE_OPENSSL + if (ssl) + { + // Finish using the SSL handle for the socket. + // This must be done *before* the socket is closed. + ssl_finish(ssl); + } +#endif + sock_close(sockctrl, NULL, 0); + } + + /* To avoid inconsistencies in the number of sock_init() */ + sock_cleanup(); + + /* Free whatever interfaces we've allocated. */ + pcap_freealldevs(*alldevs); + + return -1; +} + +/* + * Active mode routines. + * + * The old libpcap API is somewhat ugly, and makes active mode difficult + * to implement; we provide some APIs for it that work only with rpcap. + */ + +PCAP_SOCKET pcap_remoteact_accept_ex(const char *address, const char *port, const char *hostlist, char *connectinghost, struct pcap_rmtauth *auth, int uses_ssl, char *errbuf) +{ + /* socket-related variables */ + struct addrinfo hints; /* temporary struct to keep settings needed to open the new socket */ + struct addrinfo *addrinfo; /* keeps the addrinfo chain; required to open a new socket */ + struct sockaddr_storage from; /* generic sockaddr_storage variable */ + socklen_t fromlen; /* keeps the length of the sockaddr_storage variable */ + PCAP_SOCKET sockctrl; /* keeps the main socket identifier */ + SSL *ssl = NULL; /* Optional SSL handler for sockctrl */ + uint8 protocol_version; /* negotiated protocol version */ + int byte_swapped; /* 1 if server byte order is known to be the reverse of ours */ + struct activehosts *temp, *prev; /* temp var needed to scan he host list chain */ + + *connectinghost = 0; /* just in case */ + + /* Prepare to open a new server socket */ + memset(&hints, 0, sizeof(struct addrinfo)); + /* WARNING Currently it supports only ONE socket family among ipv4 and IPv6 */ + hints.ai_family = AF_INET; /* PF_UNSPEC to have both IPv4 and IPv6 server */ + hints.ai_flags = AI_PASSIVE; /* Ready to a bind() socket */ + hints.ai_socktype = SOCK_STREAM; + + /* Warning: this call can be the first one called by the user. */ + /* For this reason, we have to initialize the Winsock support. */ + if (sock_init(errbuf, PCAP_ERRBUF_SIZE) == -1) + return (PCAP_SOCKET)-1; + + /* Do the work */ + if ((port == NULL) || (port[0] == 0)) + { + addrinfo = sock_initaddress(address, + RPCAP_DEFAULT_NETPORT_ACTIVE, &hints, errbuf, + PCAP_ERRBUF_SIZE); + } + else + { + addrinfo = sock_initaddress(address, port, &hints, errbuf, + PCAP_ERRBUF_SIZE); + } + if (addrinfo == NULL) + { + return (PCAP_SOCKET)-2; + } + + if ((sockmain = sock_open(NULL, addrinfo, SOCKOPEN_SERVER, 1, errbuf, PCAP_ERRBUF_SIZE)) == INVALID_SOCKET) + { + freeaddrinfo(addrinfo); + return (PCAP_SOCKET)-2; + } + freeaddrinfo(addrinfo); + + /* Connection creation */ + fromlen = sizeof(struct sockaddr_storage); + + sockctrl = accept(sockmain, (struct sockaddr *) &from, &fromlen); + + /* We're not using sock_close, since we do not want to send a shutdown */ + /* (which is not allowed on a non-connected socket) */ + closesocket(sockmain); + sockmain = 0; + + if (sockctrl == INVALID_SOCKET) + { + sock_geterrmsg(errbuf, PCAP_ERRBUF_SIZE, "accept() failed"); + return (PCAP_SOCKET)-2; + } + + /* Promote to SSL early before any error message may be sent */ + if (uses_ssl) + { +#ifdef HAVE_OPENSSL + ssl = ssl_promotion(0, sockctrl, errbuf, PCAP_ERRBUF_SIZE); + if (! ssl) + { + sock_close(sockctrl, NULL, 0); + return (PCAP_SOCKET)-1; + } +#else + snprintf(errbuf, PCAP_ERRBUF_SIZE, "No TLS support"); + sock_close(sockctrl, NULL, 0); + return (PCAP_SOCKET)-1; +#endif + } + + /* Get the numeric for of the name of the connecting host */ + if (getnameinfo((struct sockaddr *) &from, fromlen, connectinghost, RPCAP_HOSTLIST_SIZE, NULL, 0, NI_NUMERICHOST)) + { + sock_geterrmsg(errbuf, PCAP_ERRBUF_SIZE, + "getnameinfo() failed"); + rpcap_senderror(sockctrl, ssl, 0, PCAP_ERR_REMOTEACCEPT, errbuf, NULL); +#ifdef HAVE_OPENSSL + if (ssl) + { + // Finish using the SSL handle for the socket. + // This must be done *before* the socket is closed. + ssl_finish(ssl); + } +#endif + sock_close(sockctrl, NULL, 0); + return (PCAP_SOCKET)-1; + } + + /* checks if the connecting host is among the ones allowed */ + if (sock_check_hostlist(hostlist, RPCAP_HOSTLIST_SEP, &from, errbuf, PCAP_ERRBUF_SIZE) < 0) + { + rpcap_senderror(sockctrl, ssl, 0, PCAP_ERR_REMOTEACCEPT, errbuf, NULL); +#ifdef HAVE_OPENSSL + if (ssl) + { + // Finish using the SSL handle for the socket. + // This must be done *before* the socket is closed. + ssl_finish(ssl); + } +#endif + sock_close(sockctrl, NULL, 0); + return (PCAP_SOCKET)-1; + } + + /* + * Send authentication to the remote machine. + */ + if (rpcap_doauth(sockctrl, ssl, &protocol_version, &byte_swapped, + auth, errbuf) == -1) + { + /* Unrecoverable error. */ + rpcap_senderror(sockctrl, ssl, 0, PCAP_ERR_REMOTEACCEPT, errbuf, NULL); +#ifdef HAVE_OPENSSL + if (ssl) + { + // Finish using the SSL handle for the socket. + // This must be done *before* the socket is closed. + ssl_finish(ssl); + } +#endif + sock_close(sockctrl, NULL, 0); + return (PCAP_SOCKET)-3; + } + + /* Checks that this host does not already have a cntrl connection in place */ + + /* Initialize pointers */ + temp = activeHosts; + prev = NULL; + + while (temp) + { + /* This host already has an active connection in place, so I don't have to update the host list */ + if (sock_cmpaddr(&temp->host, &from) == 0) + return sockctrl; + + prev = temp; + temp = temp->next; + } + + /* The host does not exist in the list; so I have to update the list */ + if (prev) + { + prev->next = (struct activehosts *) malloc(sizeof(struct activehosts)); + temp = prev->next; + } + else + { + activeHosts = (struct activehosts *) malloc(sizeof(struct activehosts)); + temp = activeHosts; + } + + if (temp == NULL) + { + pcapint_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, + errno, "malloc() failed"); + rpcap_senderror(sockctrl, ssl, protocol_version, PCAP_ERR_REMOTEACCEPT, errbuf, NULL); +#ifdef HAVE_OPENSSL + if (ssl) + { + // Finish using the SSL handle for the socket. + // This must be done *before* the socket is closed. + ssl_finish(ssl); + } +#endif + sock_close(sockctrl, NULL, 0); + return (PCAP_SOCKET)-1; + } + + memcpy(&temp->host, &from, fromlen); + temp->sockctrl = sockctrl; + temp->ssl = ssl; + temp->protocol_version = protocol_version; + temp->byte_swapped = byte_swapped; + temp->next = NULL; + + return sockctrl; +} + +PCAP_SOCKET pcap_remoteact_accept(const char *address, const char *port, const char *hostlist, char *connectinghost, struct pcap_rmtauth *auth, char *errbuf) +{ + return pcap_remoteact_accept_ex(address, port, hostlist, connectinghost, auth, 0, errbuf); +} + +int pcap_remoteact_close(const char *host, char *errbuf) +{ + struct activehosts *temp, *prev; /* temp var needed to scan the host list chain */ + struct addrinfo hints, *addrinfo, *ai_next; /* temp var needed to translate between hostname to its address */ + + temp = activeHosts; + prev = NULL; + + /* retrieve the network address corresponding to 'host' */ + addrinfo = NULL; + memset(&hints, 0, sizeof(struct addrinfo)); + hints.ai_family = PF_UNSPEC; + hints.ai_socktype = SOCK_STREAM; + + addrinfo = sock_initaddress(host, NULL, &hints, errbuf, + PCAP_ERRBUF_SIZE); + if (addrinfo == NULL) + { + return -1; + } + + while (temp) + { + ai_next = addrinfo; + while (ai_next) + { + if (sock_cmpaddr(&temp->host, (struct sockaddr_storage *) ai_next->ai_addr) == 0) + { + struct rpcap_header header; + int status = 0; + + /* Close this connection */ + rpcap_createhdr(&header, temp->protocol_version, + RPCAP_MSG_CLOSE, 0, 0); + + /* + * Don't check for errors, since we're + * just cleaning up. + */ + if (sock_send(temp->sockctrl, temp->ssl, + (char *)&header, + sizeof(struct rpcap_header), errbuf, + PCAP_ERRBUF_SIZE) < 0) + { + /* + * Let that error be the one we + * report. + */ +#ifdef HAVE_OPENSSL + if (temp->ssl) + { + // Finish using the SSL handle + // for the socket. + // This must be done *before* + // the socket is closed. + ssl_finish(temp->ssl); + } +#endif + (void)sock_close(temp->sockctrl, NULL, + 0); + status = -1; + } + else + { +#ifdef HAVE_OPENSSL + if (temp->ssl) + { + // Finish using the SSL handle + // for the socket. + // This must be done *before* + // the socket is closed. + ssl_finish(temp->ssl); + } +#endif + if (sock_close(temp->sockctrl, errbuf, + PCAP_ERRBUF_SIZE) == -1) + status = -1; + } + + /* + * Remove the host from the list of active + * hosts. + */ + if (prev) + prev->next = temp->next; + else + activeHosts = temp->next; + + freeaddrinfo(addrinfo); + + free(temp); + + /* To avoid inconsistencies in the number of sock_init() */ + sock_cleanup(); + + return status; + } + + ai_next = ai_next->ai_next; + } + prev = temp; + temp = temp->next; + } + + if (addrinfo) + freeaddrinfo(addrinfo); + + /* To avoid inconsistencies in the number of sock_init() */ + sock_cleanup(); + + snprintf(errbuf, PCAP_ERRBUF_SIZE, "The host you want to close the active connection is not known"); + return -1; +} + +void pcap_remoteact_cleanup(void) +{ +# ifdef HAVE_OPENSSL + if (ssl_main) + { + // Finish using the SSL handle for the main active socket. + // This must be done *before* the socket is closed. + ssl_finish(ssl_main); + ssl_main = NULL; + } +# endif + + /* Very dirty, but it works */ + if (sockmain) + { + closesocket(sockmain); + + /* To avoid inconsistencies in the number of sock_init() */ + sock_cleanup(); + } +} + +int pcap_remoteact_list(char *hostlist, char sep, int size, char *errbuf) +{ + struct activehosts *temp; /* temp var needed to scan the host list chain */ + size_t len; + char hoststr[RPCAP_HOSTLIST_SIZE + 1]; + + temp = activeHosts; + + len = 0; + *hostlist = 0; + + while (temp) + { + /*int sock_getascii_addrport(const struct sockaddr_storage *sockaddr, char *address, int addrlen, char *port, int portlen, int flags, char *errbuf, int errbuflen) */ + + /* Get the numeric form of the name of the connecting host */ + if (sock_getascii_addrport((struct sockaddr_storage *) &temp->host, hoststr, + RPCAP_HOSTLIST_SIZE, NULL, 0, NI_NUMERICHOST, errbuf, PCAP_ERRBUF_SIZE) != -1) + /* if (getnameinfo( (struct sockaddr *) &temp->host, sizeof (struct sockaddr_storage), hoststr, */ + /* RPCAP_HOSTLIST_SIZE, NULL, 0, NI_NUMERICHOST) ) */ + { + /* sock_geterrmsg(errbuf, PCAP_ERRBUF_SIZE, */ + /* "getnameinfo() failed"); */ + return -1; + } + + len = len + strlen(hoststr) + 1 /* the separator */; + + if ((size < 0) || (len >= (size_t)size)) + { + snprintf(errbuf, PCAP_ERRBUF_SIZE, "The string you provided is not able to keep " + "the hostnames for all the active connections"); + return -1; + } + + pcapint_strlcat(hostlist, hoststr, PCAP_ERRBUF_SIZE); + hostlist[len - 1] = sep; + hostlist[len] = 0; + + temp = temp->next; + } + + return 0; +} + +/* + * Receive the header of a message. + */ +static int rpcap_recv_msg_header(PCAP_SOCKET sock, SSL *ssl, struct rpcap_header *header, char *errbuf) +{ + int nrecv; + + nrecv = sock_recv(sock, ssl, (char *) header, sizeof(struct rpcap_header), + SOCK_RECEIVEALL_YES|SOCK_EOF_IS_ERROR, errbuf, + PCAP_ERRBUF_SIZE); + if (nrecv == -1) + { + /* Network error. */ + return -1; + } + header->plen = ntohl(header->plen); + return 0; +} + +/* + * Make sure the protocol version of a received message is what we were + * expecting. + */ +static int rpcap_check_msg_ver(PCAP_SOCKET sock, SSL *ssl, uint8 expected_ver, struct rpcap_header *header, char *errbuf) +{ + /* + * Did the server specify the version we negotiated? + */ + if (header->ver != expected_ver) + { + /* + * Discard the rest of the message. + */ + if (rpcap_discard(sock, ssl, header->plen, errbuf) == -1) + return -1; + + /* + * Tell our caller that it's not the negotiated version. + */ + if (errbuf != NULL) + { + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "Server sent us a message with version %u when we were expecting %u", + header->ver, expected_ver); + } + return -1; + } + return 0; +} + +/* + * Check the message type of a received message, which should either be + * the expected message type or RPCAP_MSG_ERROR. + */ +static int rpcap_check_msg_type(PCAP_SOCKET sock, SSL *ssl, uint8 request_type, struct rpcap_header *header, uint16 *errcode, char *errbuf) +{ + const char *request_type_string; + const char *msg_type_string; + + /* + * What type of message is it? + */ + if (header->type == RPCAP_MSG_ERROR) + { + /* + * The server reported an error. + * Hand that error back to our caller. + */ + *errcode = ntohs(header->value); + rpcap_msg_err(sock, ssl, header->plen, errbuf); + return -1; + } + + *errcode = 0; + + /* + * For a given request type value, the expected reply type value + * is the request type value with ORed with RPCAP_MSG_IS_REPLY. + */ + if (header->type != (request_type | RPCAP_MSG_IS_REPLY)) + { + /* + * This isn't a reply to the request we sent. + */ + + /* + * Discard the rest of the message. + */ + if (rpcap_discard(sock, ssl, header->plen, errbuf) == -1) + return -1; + + /* + * Tell our caller about it. + */ + request_type_string = rpcap_msg_type_string(request_type); + msg_type_string = rpcap_msg_type_string(header->type); + if (errbuf != NULL) + { + if (request_type_string == NULL) + { + /* This should not happen. */ + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "rpcap_check_msg_type called for request message with type %u", + request_type); + return -1; + } + if (msg_type_string != NULL) + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "%s message received in response to a %s message", + msg_type_string, request_type_string); + else + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "Message of unknown type %u message received in response to a %s request", + header->type, request_type_string); + } + return -1; + } + + return 0; +} + +/* + * Receive and process the header of a message. + */ +static int rpcap_process_msg_header(PCAP_SOCKET sock, SSL *ssl, uint8 expected_ver, uint8 request_type, struct rpcap_header *header, char *errbuf) +{ + uint16 errcode; + + if (rpcap_recv_msg_header(sock, ssl, header, errbuf) == -1) + { + /* Network error. */ + return -1; + } + + /* + * Did the server specify the version we negotiated? + */ + if (rpcap_check_msg_ver(sock, ssl, expected_ver, header, errbuf) == -1) + return -1; + + /* + * Check the message type. + */ + return rpcap_check_msg_type(sock, ssl, request_type, header, + &errcode, errbuf); +} + +/* + * Read data from a message. + * If we're trying to read more data that remains, puts an error + * message into errmsgbuf and returns -2. Otherwise, tries to read + * the data and, if that succeeds, subtracts the amount read from + * the number of bytes of data that remains. + * Returns 0 on success, logs a message and returns -1 on a network + * error. + */ +static int rpcap_recv(PCAP_SOCKET sock, SSL *ssl, void *buffer, size_t toread, uint32 *plen, char *errbuf) +{ + int nread; + + if (toread > *plen) + { + /* The server sent us a bad message */ + snprintf(errbuf, PCAP_ERRBUF_SIZE, "Message payload is too short"); + return -1; + } + nread = sock_recv(sock, ssl, buffer, toread, + SOCK_RECEIVEALL_YES|SOCK_EOF_IS_ERROR, errbuf, PCAP_ERRBUF_SIZE); + if (nread == -1) + { + return -1; + } + *plen -= nread; + return 0; +} + +/* + * This handles the RPCAP_MSG_ERROR message. + */ +static void rpcap_msg_err(PCAP_SOCKET sockctrl, SSL *ssl, uint32 plen, char *remote_errbuf) +{ + char errbuf[PCAP_ERRBUF_SIZE]; + + if (plen >= PCAP_ERRBUF_SIZE) + { + /* + * Message is too long; just read as much of it as we + * can into the buffer provided, and discard the rest. + */ + if (sock_recv(sockctrl, ssl, remote_errbuf, PCAP_ERRBUF_SIZE - 1, + SOCK_RECEIVEALL_YES|SOCK_EOF_IS_ERROR, errbuf, + PCAP_ERRBUF_SIZE) == -1) + { + // Network error. + DIAG_OFF_FORMAT_TRUNCATION + snprintf(remote_errbuf, PCAP_ERRBUF_SIZE, "Read of error message from client failed: %s", errbuf); + DIAG_ON_FORMAT_TRUNCATION + return; + } + + /* + * Null-terminate it. + */ + remote_errbuf[PCAP_ERRBUF_SIZE - 1] = '\0'; + +#ifdef _WIN32 + /* + * If we're not in UTF-8 mode, convert it to the local + * code page. + */ + if (!pcapint_utf_8_mode) + utf_8_to_acp_truncated(remote_errbuf); +#endif + + /* + * Throw away the rest. + */ + (void)rpcap_discard(sockctrl, ssl, plen - (PCAP_ERRBUF_SIZE - 1), remote_errbuf); + } + else if (plen == 0) + { + /* Empty error string. */ + remote_errbuf[0] = '\0'; + } + else + { + if (sock_recv(sockctrl, ssl, remote_errbuf, plen, + SOCK_RECEIVEALL_YES|SOCK_EOF_IS_ERROR, errbuf, + PCAP_ERRBUF_SIZE) == -1) + { + // Network error. + DIAG_OFF_FORMAT_TRUNCATION + snprintf(remote_errbuf, PCAP_ERRBUF_SIZE, "Read of error message from client failed: %s", errbuf); + DIAG_ON_FORMAT_TRUNCATION + return; + } + + /* + * Null-terminate it. + */ + remote_errbuf[plen] = '\0'; + } +} + +/* + * Discard data from a connection. + * Mostly used to discard wrong-sized messages. + * Returns 0 on success, logs a message and returns -1 on a network + * error. + */ +static int rpcap_discard(PCAP_SOCKET sock, SSL *ssl, uint32 len, char *errbuf) +{ + if (len != 0) + { + if (sock_discard(sock, ssl, len, errbuf, PCAP_ERRBUF_SIZE) == -1) + { + // Network error. + return -1; + } + } + return 0; +} + +/* + * Read bytes into the pcap_t's buffer until we have the specified + * number of bytes read or we get an error or interrupt indication. + */ +static int rpcap_read_packet_msg(struct pcap_rpcap const *rp, pcap_t *p, size_t size) +{ + u_char *bp; + int cc; + int bytes_read; + + bp = p->bp; + cc = p->cc; + + /* + * Loop until we have the amount of data requested or we get + * an error or interrupt. + */ + while ((size_t)cc < size) + { + /* + * We haven't read all of the packet header yet. + * Read what remains, which could be all of it. + */ + bytes_read = sock_recv(rp->rmt_sockdata, rp->data_ssl, bp, size - cc, + SOCK_RECEIVEALL_NO|SOCK_EOF_IS_ERROR, p->errbuf, + PCAP_ERRBUF_SIZE); + + if (bytes_read == -1) + { + /* + * Network error. Update the read pointer and + * byte count, and return an error indication. + */ + p->bp = bp; + p->cc = cc; + return -1; + } + if (bytes_read == -3) + { + /* + * Interrupted receive. Update the read + * pointer and byte count, and return + * an interrupted indication. + */ + p->bp = bp; + p->cc = cc; + return -3; + } + if (bytes_read == 0) + { + /* + * EOF - server terminated the connection. + * Update the read pointer and byte count, and + * return an error indication. + */ + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "The server terminated the connection."); + return -1; + } + bp += bytes_read; + cc += bytes_read; + } + p->bp = bp; + p->cc = cc; + return 0; +} |