diff options
Diffstat (limited to 'pcap-bpf.c')
| -rw-r--r-- | pcap-bpf.c | 1842 |
1 files changed, 1586 insertions, 256 deletions
diff --git a/pcap-bpf.c b/pcap-bpf.c index 027913e7f4f93..6ec6515fb7c72 100644 --- a/pcap-bpf.c +++ b/pcap-bpf.c @@ -20,7 +20,7 @@ */ #ifndef lint static const char rcsid[] _U_ = - "@(#) $Header: /tcpdump/master/libpcap/pcap-bpf.c,v 1.86.2.12 2007/06/15 17:57:27 guy Exp $ (LBL)"; + "@(#) $Header: /tcpdump/master/libpcap/pcap-bpf.c,v 1.99.2.17 2008-09-16 18:43:02 guy Exp $ (LBL)"; #endif #ifdef HAVE_CONFIG_H @@ -28,6 +28,9 @@ static const char rcsid[] _U_ = #endif #include <sys/param.h> /* optionally get BSD define */ +#ifdef HAVE_ZEROCOPY_BPF +#include <sys/mman.h> +#endif #include <sys/time.h> #include <sys/timeb.h> #include <sys/socket.h> @@ -35,12 +38,16 @@ static const char rcsid[] _U_ = #include <sys/ioctl.h> #include <sys/utsname.h> +#ifdef HAVE_ZEROCOPY_BPF +#include <machine/atomic.h> +#endif + #include <net/if.h> #ifdef _AIX /* - * Make "pcap.h" not include "pcap-bpf.h"; we are going to include the + * Make "pcap.h" not include "pcap/bpf.h"; we are going to include the * native OS version, as we need "struct bpf_config" from it. */ #define PCAP_DONT_INCLUDE_PCAP_BPF_H @@ -92,6 +99,10 @@ static int odmlockid = 0; #include <string.h> #include <unistd.h> +#ifdef HAVE_NET_IF_MEDIA_H +# include <net/if_media.h> +#endif + #include "pcap-int.h" #ifdef HAVE_DAG_API @@ -102,12 +113,579 @@ static int odmlockid = 0; #include "os-proto.h" #endif -#include "gencode.h" /* for "no_optimize" */ +#ifdef BIOCGDLTLIST +# if (defined(HAVE_NET_IF_MEDIA_H) && defined(IFM_IEEE80211)) && !defined(__APPLE__) +#define HAVE_BSD_IEEE80211 +# endif + +# if defined(__APPLE__) || defined(HAVE_BSD_IEEE80211) +static int find_802_11(struct bpf_dltlist *); + +# ifdef HAVE_BSD_IEEE80211 +static int monitor_mode(pcap_t *, int); +# endif + +# if defined(__APPLE__) +static void remove_en(pcap_t *); +static void remove_802_11(pcap_t *); +# endif + +# endif /* defined(__APPLE__) || defined(HAVE_BSD_IEEE80211) */ + +#endif /* BIOCGDLTLIST */ + +/* + * We include the OS's <net/bpf.h>, not our "pcap/bpf.h", so we probably + * don't get DLT_DOCSIS defined. + */ +#ifndef DLT_DOCSIS +#define DLT_DOCSIS 143 +#endif + +/* + * On OS X, we don't even get any of the 802.11-plus-radio-header DLT_'s + * defined, even though some of them are used by various Airport drivers. + */ +#ifndef DLT_PRISM_HEADER +#define DLT_PRISM_HEADER 119 +#endif +#ifndef DLT_AIRONET_HEADER +#define DLT_AIRONET_HEADER 120 +#endif +#ifndef DLT_IEEE802_11_RADIO +#define DLT_IEEE802_11_RADIO 127 +#endif +#ifndef DLT_IEEE802_11_RADIO_AVS +#define DLT_IEEE802_11_RADIO_AVS 163 +#endif +static int pcap_can_set_rfmon_bpf(pcap_t *p); +static int pcap_activate_bpf(pcap_t *p); static int pcap_setfilter_bpf(pcap_t *p, struct bpf_program *fp); static int pcap_setdirection_bpf(pcap_t *, pcap_direction_t); static int pcap_set_datalink_bpf(pcap_t *p, int dlt); +#ifdef HAVE_ZEROCOPY_BPF +/* + * For zerocopy bpf, we need to override the setnonblock/getnonblock routines + * so we don't call select(2) if the pcap handle is in non-blocking mode. We + * preserve the timeout supplied by pcap_open functions to make sure it + * does not get clobbered if the pcap handle moves between blocking and non- + * blocking mode. + */ +static int +pcap_getnonblock_zbuf(pcap_t *p, char *errbuf) +{ + /* + * Use a negative value for the timeout to represent that the + * pcap handle is in non-blocking mode. + */ + return (p->md.timeout < 0); +} + +static int +pcap_setnonblock_zbuf(pcap_t *p, int nonblock, char *errbuf) +{ + /* + * Map each value to the corresponding 2's complement, to + * preserve the timeout value provided with pcap_set_timeout. + * (from pcap-linux.c). + */ + if (nonblock) { + if (p->md.timeout > 0) + p->md.timeout = p->md.timeout * -1 - 1; + } else + if (p->md.timeout < 0) + p->md.timeout = (p->md.timeout + 1) * -1; + return (0); +} + +/* + * Zero-copy specific close method. Un-map the shared buffers then call + * pcap_cleanup_live_common. + */ +static void +pcap_cleanup_zbuf(pcap_t *p) +{ + /* + * Delete the mappings. Note that p->buffer gets initialized to one + * of the mmapped regions in this case, so do not try and free it + * directly; null it out so that pcap_cleanup_live_common() doesn't + * try to free it. + */ + if (p->md.zbuf1 != MAP_FAILED && p->md.zbuf1 != NULL) + (void) munmap(p->md.zbuf1, p->md.zbufsize); + if (p->md.zbuf2 != MAP_FAILED && p->md.zbuf2 != NULL) + (void) munmap(p->md.zbuf2, p->md.zbufsize); + p->buffer = NULL; + pcap_cleanup_live_common(p); +} + +/* + * Zero-copy BPF buffer routines to check for and acknowledge BPF data in + * shared memory buffers. + * + * pcap_next_zbuf_shm(): Check for a newly available shared memory buffer, + * and set up p->buffer and cc to reflect one if available. Notice that if + * there was no prior buffer, we select zbuf1 as this will be the first + * buffer filled for a fresh BPF session. + */ +static int +pcap_next_zbuf_shm(pcap_t *p, int *cc) +{ + struct bpf_zbuf_header *bzh; + + if (p->md.zbuffer == p->md.zbuf2 || p->md.zbuffer == NULL) { + bzh = (struct bpf_zbuf_header *)p->md.zbuf1; + if (bzh->bzh_user_gen != + atomic_load_acq_int(&bzh->bzh_kernel_gen)) { + p->md.bzh = bzh; + p->md.zbuffer = (u_char *)p->md.zbuf1; + p->buffer = p->md.zbuffer + sizeof(*bzh); + *cc = bzh->bzh_kernel_len; + return (1); + } + } else if (p->md.zbuffer == p->md.zbuf1) { + bzh = (struct bpf_zbuf_header *)p->md.zbuf2; + if (bzh->bzh_user_gen != + atomic_load_acq_int(&bzh->bzh_kernel_gen)) { + p->md.bzh = bzh; + p->md.zbuffer = (u_char *)p->md.zbuf2; + p->buffer = p->md.zbuffer + sizeof(*bzh); + *cc = bzh->bzh_kernel_len; + return (1); + } + } + *cc = 0; + return (0); +} + +/* + * pcap_next_zbuf() -- Similar to pcap_next_zbuf_shm(), except wait using + * select() for data or a timeout, and possibly force rotation of the buffer + * in the event we time out or are in immediate mode. Invoke the shared + * memory check before doing system calls in order to avoid doing avoidable + * work. + */ +static int +pcap_next_zbuf(pcap_t *p, int *cc) +{ + struct bpf_zbuf bz; + struct timeval tv; + struct timespec cur; + fd_set r_set; + int data, r; + int expire, tmout; + +#define TSTOMILLI(ts) (((ts)->tv_sec * 1000) + ((ts)->tv_nsec / 1000000)) + /* + * Start out by seeing whether anything is waiting by checking the + * next shared memory buffer for data. + */ + data = pcap_next_zbuf_shm(p, cc); + if (data) + return (data); + /* + * If a previous sleep was interrupted due to signal delivery, make + * sure that the timeout gets adjusted accordingly. This requires + * that we analyze when the timeout should be been expired, and + * subtract the current time from that. If after this operation, + * our timeout is less then or equal to zero, handle it like a + * regular timeout. + */ + tmout = p->md.timeout; + if (tmout) + (void) clock_gettime(CLOCK_MONOTONIC, &cur); + if (p->md.interrupted && p->md.timeout) { + expire = TSTOMILLI(&p->md.firstsel) + p->md.timeout; + tmout = expire - TSTOMILLI(&cur); +#undef TSTOMILLI + if (tmout <= 0) { + p->md.interrupted = 0; + data = pcap_next_zbuf_shm(p, cc); + if (data) + return (data); + if (ioctl(p->fd, BIOCROTZBUF, &bz) < 0) { + (void) snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "BIOCROTZBUF: %s", strerror(errno)); + return (PCAP_ERROR); + } + return (pcap_next_zbuf_shm(p, cc)); + } + } + /* + * No data in the buffer, so must use select() to wait for data or + * the next timeout. Note that we only call select if the handle + * is in blocking mode. + */ + if (p->md.timeout >= 0) { + FD_ZERO(&r_set); + FD_SET(p->fd, &r_set); + if (tmout != 0) { + tv.tv_sec = tmout / 1000; + tv.tv_usec = (tmout * 1000) % 1000000; + } + r = select(p->fd + 1, &r_set, NULL, NULL, + p->md.timeout != 0 ? &tv : NULL); + if (r < 0 && errno == EINTR) { + if (!p->md.interrupted && p->md.timeout) { + p->md.interrupted = 1; + p->md.firstsel = cur; + } + return (0); + } else if (r < 0) { + (void) snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "select: %s", strerror(errno)); + return (PCAP_ERROR); + } + } + p->md.interrupted = 0; + /* + * Check again for data, which may exist now that we've either been + * woken up as a result of data or timed out. Try the "there's data" + * case first since it doesn't require a system call. + */ + data = pcap_next_zbuf_shm(p, cc); + if (data) + return (data); + /* + * Try forcing a buffer rotation to dislodge timed out or immediate + * data. + */ + if (ioctl(p->fd, BIOCROTZBUF, &bz) < 0) { + (void) snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "BIOCROTZBUF: %s", strerror(errno)); + return (PCAP_ERROR); + } + return (pcap_next_zbuf_shm(p, cc)); +} + +/* + * Notify kernel that we are done with the buffer. We don't reset zbuffer so + * that we know which buffer to use next time around. + */ +static int +pcap_ack_zbuf(pcap_t *p) +{ + + atomic_store_rel_int(&p->md.bzh->bzh_user_gen, + p->md.bzh->bzh_kernel_gen); + p->md.bzh = NULL; + p->buffer = NULL; + return (0); +} +#endif + +pcap_t * +pcap_create(const char *device, char *ebuf) +{ + pcap_t *p; + +#ifdef HAVE_DAG_API + if (strstr(device, "dag")) + return (dag_create(device, ebuf)); +#endif /* HAVE_DAG_API */ + + p = pcap_create_common(device, ebuf); + if (p == NULL) + return (NULL); + + p->activate_op = pcap_activate_bpf; + p->can_set_rfmon_op = pcap_can_set_rfmon_bpf; + return (p); +} + +static int +bpf_open(pcap_t *p) +{ + int fd; +#ifdef HAVE_CLONING_BPF + static const char device[] = "/dev/bpf"; +#else + int n = 0; + char device[sizeof "/dev/bpf0000000000"]; +#endif + +#ifdef _AIX + /* + * Load the bpf driver, if it isn't already loaded, + * and create the BPF device entries, if they don't + * already exist. + */ + if (bpf_load(p->errbuf) == PCAP_ERROR) + return (PCAP_ERROR); +#endif + +#ifdef HAVE_CLONING_BPF + if ((fd = open(device, O_RDWR)) == -1 && + (errno != EACCES || (fd = open(device, O_RDONLY)) == -1)) { + if (errno == EACCES) + fd = PCAP_ERROR_PERM_DENIED; + else + fd = PCAP_ERROR; + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "(cannot open device) %s: %s", device, pcap_strerror(errno)); + } +#else + /* + * Go through all the minors and find one that isn't in use. + */ + do { + (void)snprintf(device, sizeof(device), "/dev/bpf%d", n++); + /* + * Initially try a read/write open (to allow the inject + * method to work). If that fails due to permission + * issues, fall back to read-only. This allows a + * non-root user to be granted specific access to pcap + * capabilities via file permissions. + * + * XXX - we should have an API that has a flag that + * controls whether to open read-only or read-write, + * so that denial of permission to send (or inability + * to send, if sending packets isn't supported on + * the device in question) can be indicated at open + * time. + */ + fd = open(device, O_RDWR); + if (fd == -1 && errno == EACCES) + fd = open(device, O_RDONLY); + } while (fd < 0 && errno == EBUSY); + + /* + * XXX better message for all minors used + */ + if (fd < 0) { + if (errno == EACCES) + fd = PCAP_ERROR_PERM_DENIED; + else + fd = PCAP_ERROR; + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "(no devices found) %s: %s", + device, pcap_strerror(errno)); + } +#endif + + return (fd); +} + +#ifdef BIOCGDLTLIST +static int +get_dlt_list(int fd, int v, struct bpf_dltlist *bdlp, char *ebuf) +{ + memset(bdlp, 0, sizeof(*bdlp)); + if (ioctl(fd, BIOCGDLTLIST, (caddr_t)bdlp) == 0) { + u_int i; + int is_ethernet; + + bdlp->bfl_list = (u_int *) malloc(sizeof(u_int) * (bdlp->bfl_len + 1)); + if (bdlp->bfl_list == NULL) { + (void)snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s", + pcap_strerror(errno)); + return (PCAP_ERROR); + } + + if (ioctl(fd, BIOCGDLTLIST, (caddr_t)bdlp) < 0) { + (void)snprintf(ebuf, PCAP_ERRBUF_SIZE, + "BIOCGDLTLIST: %s", pcap_strerror(errno)); + free(bdlp->bfl_list); + return (PCAP_ERROR); + } + + /* + * OK, for real Ethernet devices, add DLT_DOCSIS to the + * list, so that an application can let you choose it, + * in case you're capturing DOCSIS traffic that a Cisco + * Cable Modem Termination System is putting out onto + * an Ethernet (it doesn't put an Ethernet header onto + * the wire, it puts raw DOCSIS frames out on the wire + * inside the low-level Ethernet framing). + * + * A "real Ethernet device" is defined here as a device + * that has a link-layer type of DLT_EN10MB and that has + * no alternate link-layer types; that's done to exclude + * 802.11 interfaces (which might or might not be the + * right thing to do, but I suspect it is - Ethernet <-> + * 802.11 bridges would probably badly mishandle frames + * that don't have Ethernet headers). + */ + if (v == DLT_EN10MB) { + is_ethernet = 1; + for (i = 0; i < bdlp->bfl_len; i++) { + if (bdlp->bfl_list[i] != DLT_EN10MB) { + is_ethernet = 0; + break; + } + } + if (is_ethernet) { + /* + * We reserved one more slot at the end of + * the list. + */ + bdlp->bfl_list[bdlp->bfl_len] = DLT_DOCSIS; + bdlp->bfl_len++; + } + } + } else { + /* + * EINVAL just means "we don't support this ioctl on + * this device"; don't treat it as an error. + */ + if (errno != EINVAL) { + (void)snprintf(ebuf, PCAP_ERRBUF_SIZE, + "BIOCGDLTLIST: %s", pcap_strerror(errno)); + return (PCAP_ERROR); + } + } + return (0); +} +#endif + +static int +pcap_can_set_rfmon_bpf(pcap_t *p) +{ +#if defined(__APPLE__) + struct utsname osinfo; + struct ifreq ifr; + int fd; +#ifdef BIOCGDLTLIST + struct bpf_dltlist bdl; +#endif + + /* + * The joys of monitor mode on OS X. + * + * Prior to 10.4, it's not supported at all. + * + * In 10.4, if adapter enN supports monitor mode, there's a + * wltN adapter corresponding to it; you open it, instead of + * enN, to get monitor mode. You get whatever link-layer + * headers it supplies. + * + * In 10.5, and, we assume, later releases, if adapter enN + * supports monitor mode, it offers, among its selectable + * DLT_ values, values that let you get the 802.11 header; + * selecting one of those values puts the adapter into monitor + * mode (i.e., you can't get 802.11 headers except in monitor + * mode, and you can't get Ethernet headers in monitor mode). + */ + if (uname(&osinfo) == -1) { + /* + * Can't get the OS version; just say "no". + */ + return (0); + } + /* + * We assume osinfo.sysname is "Darwin", because + * __APPLE__ is defined. We just check the version. + */ + if (osinfo.release[0] < '8' && osinfo.release[1] == '.') { + /* + * 10.3 (Darwin 7.x) or earlier. + * Monitor mode not supported. + */ + return (0); + } + if (osinfo.release[0] == '8' && osinfo.release[1] == '.') { + /* + * 10.4 (Darwin 8.x). s/en/wlt/, and check + * whether the device exists. + */ + if (strncmp(p->opt.source, "en", 2) != 0) { + /* + * Not an enN device; no monitor mode. + */ + return (0); + } + fd = socket(AF_INET, SOCK_DGRAM, 0); + if (fd == -1) { + (void)snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "socket: %s", pcap_strerror(errno)); + return (PCAP_ERROR); + } + strlcpy(ifr.ifr_name, "wlt", sizeof(ifr.ifr_name)); + strlcat(ifr.ifr_name, p->opt.source + 2, sizeof(ifr.ifr_name)); + if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) { + /* + * No such device? + */ + close(fd); + return (0); + } + close(fd); + return (1); + } + +#ifdef BIOCGDLTLIST + /* + * Everything else is 10.5 or later; for those, + * we just open the enN device, and check whether + * we have any 802.11 devices. + * + * First, open a BPF device. + */ + fd = bpf_open(p); + if (fd < 0) + return (fd); + + /* + * Now bind to the device. + */ + (void)strncpy(ifr.ifr_name, p->opt.source, sizeof(ifr.ifr_name)); + if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) < 0) { + if (errno == ENETDOWN) { + /* + * Return a "network down" indication, so that + * the application can report that rather than + * saying we had a mysterious failure and + * suggest that they report a problem to the + * libpcap developers. + */ + close(fd); + return (PCAP_ERROR_IFACE_NOT_UP); + } else { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "BIOCSETIF: %s: %s", + p->opt.source, pcap_strerror(errno)); + close(fd); + return (PCAP_ERROR); + } + } + + /* + * We know the default link type -- now determine all the DLTs + * this interface supports. If this fails with EINVAL, it's + * not fatal; we just don't get to use the feature later. + * (We don't care about DLT_DOCSIS, so we pass DLT_NULL + * as the default DLT for this adapter.) + */ + if (get_dlt_list(fd, DLT_NULL, &bdl, p->errbuf) == PCAP_ERROR) { + close(fd); + return (PCAP_ERROR); + } + if (find_802_11(&bdl) != -1) { + /* + * We have an 802.11 DLT, so we can set monitor mode. + */ + free(bdl.bfl_list); + close(fd); + return (1); + } + free(bdl.bfl_list); +#endif /* BIOCGDLTLIST */ + return (0); +#elif defined(HAVE_BSD_IEEE80211) + int ret; + + ret = monitor_mode(p, 0); + if (ret == PCAP_ERROR_RFMON_NOTSUP) + return (0); /* not an error, just a "can't do" */ + if (ret == 0) + return (1); /* success */ + return (ret); +#else + return (0); +#endif +} + static int pcap_stats_bpf(pcap_t *p, struct pcap_stat *ps) { @@ -129,7 +707,7 @@ pcap_stats_bpf(pcap_t *p, struct pcap_stat *ps) if (ioctl(p->fd, BIOCGSTATS, (caddr_t)&s) < 0) { snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGSTATS: %s", pcap_strerror(errno)); - return (-1); + return (PCAP_ERROR); } ps->ps_recv = s.bs_recv; @@ -144,12 +722,13 @@ pcap_read_bpf(pcap_t *p, int cnt, pcap_handler callback, u_char *user) int n = 0; register u_char *bp, *ep; u_char *datap; - struct bpf_insn *fcode; #ifdef PCAP_FDDIPAD register int pad; #endif +#ifdef HAVE_ZEROCOPY_BPF + int i; +#endif - fcode = p->md.use_bpf ? NULL : p->fcode.bf_insns; again: /* * Has "pcap_breakloop()" been called? @@ -157,15 +736,36 @@ pcap_read_bpf(pcap_t *p, int cnt, pcap_handler callback, u_char *user) if (p->break_loop) { /* * Yes - clear the flag that indicates that it - * has, and return -2 to indicate that we were - * told to break out of the loop. + * has, and return PCAP_ERROR_BREAK to indicate + * that we were told to break out of the loop. */ p->break_loop = 0; - return (-2); + return (PCAP_ERROR_BREAK); } cc = p->cc; if (p->cc == 0) { - cc = read(p->fd, (char *)p->buffer, p->bufsize); + /* + * When reading without zero-copy from a file descriptor, we + * use a single buffer and return a length of data in the + * buffer. With zero-copy, we update the p->buffer pointer + * to point at whatever underlying buffer contains the next + * data and update cc to reflect the data found in the + * buffer. + */ +#ifdef HAVE_ZEROCOPY_BPF + if (p->md.zerocopy) { + if (p->buffer != NULL) + pcap_ack_zbuf(p); + i = pcap_next_zbuf(p, &cc); + if (i == 0) + goto again; + if (i < 0) + return (PCAP_ERROR); + } else +#endif + { + cc = read(p->fd, (char *)p->buffer, p->bufsize); + } if (cc < 0) { /* Don't choke when we get ptraced */ switch (errno) { @@ -180,16 +780,16 @@ pcap_read_bpf(pcap_t *p, int cnt, pcap_handler callback, u_char *user) * * For some unknown reason the uiomove() * operation in the bpf kernel extension - * used to copy the buffer into user + * used to copy the buffer into user * space sometimes returns EFAULT. I have * no idea why this is the case given that - * a kernel debugger shows the user buffer - * is correct. This problem appears to - * be mostly mitigated by the memset of - * the buffer before it is first used. + * a kernel debugger shows the user buffer + * is correct. This problem appears to + * be mostly mitigated by the memset of + * the buffer before it is first used. * Very strange.... Shaun Clowes * - * In any case this means that we shouldn't + * In any case this means that we shouldn't * treat EFAULT as a fatal error; as we * don't have an API for returning * a "some packets were dropped since @@ -197,8 +797,8 @@ pcap_read_bpf(pcap_t *p, int cnt, pcap_handler callback, u_char *user) * we just ignore EFAULT and keep reading. */ goto again; -#endif - +#endif + case EWOULDBLOCK: return (0); #if defined(sun) && !defined(BSD) @@ -218,7 +818,7 @@ pcap_read_bpf(pcap_t *p, int cnt, pcap_handler callback, u_char *user) } snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "read: %s", pcap_strerror(errno)); - return (-1); + return (PCAP_ERROR); } bp = p->buffer; } else @@ -238,16 +838,17 @@ pcap_read_bpf(pcap_t *p, int cnt, pcap_handler callback, u_char *user) /* * Has "pcap_breakloop()" been called? * If so, return immediately - if we haven't read any - * packets, clear the flag and return -2 to indicate - * that we were told to break out of the loop, otherwise - * leave the flag set, so that the *next* call will break - * out of the loop without having read any packets, and - * return the number of packets we've processed so far. + * packets, clear the flag and return PCAP_ERROR_BREAK + * to indicate that we were told to break out of the loop, + * otherwise leave the flag set, so that the *next* call + * will break out of the loop without having read any + * packets, and return the number of packets we've + * processed so far. */ if (p->break_loop) { if (n == 0) { p->break_loop = 0; - return (-2); + return (PCAP_ERROR_BREAK); } else { p->bp = bp; p->cc = ep - bp; @@ -260,7 +861,8 @@ pcap_read_bpf(pcap_t *p, int cnt, pcap_handler callback, u_char *user) datap = bp + hdrlen; /* * Short-circuit evaluation: if using BPF filter - * in kernel, no need to do it now. + * in kernel, no need to do it now - we already know + * the packet passed the filter. * #ifdef PCAP_FDDIPAD * Note: the filter code was generated assuming @@ -270,8 +872,8 @@ pcap_read_bpf(pcap_t *p, int cnt, pcap_handler callback, u_char *user) * skipping that padding. #endif */ - if (fcode == NULL || - bpf_filter(fcode, datap, bhp->bh_datalen, caplen)) { + if (p->md.use_bpf || + bpf_filter(p->fcode.bf_insns, datap, bhp->bh_datalen, caplen)) { struct pcap_pkthdr pkthdr; pkthdr.ts.tv_sec = bhp->bh_tstamp.tv_sec; @@ -349,7 +951,7 @@ pcap_inject_bpf(pcap_t *p, const void *buf, size_t size) (void)snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send: can't turn off BIOCSHDRCMPLT: %s", pcap_strerror(errno)); - return (-1); + return (PCAP_ERROR); } /* @@ -361,13 +963,13 @@ pcap_inject_bpf(pcap_t *p, const void *buf, size_t size) if (ret == -1) { snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send: %s", pcap_strerror(errno)); - return (-1); + return (PCAP_ERROR); } return (ret); } #ifdef _AIX -static int +static int bpf_odminit(char *errbuf) { char *errstr; @@ -378,7 +980,7 @@ bpf_odminit(char *errbuf) snprintf(errbuf, PCAP_ERRBUF_SIZE, "bpf_load: odm_initialize failed: %s", errstr); - return (-1); + return (PCAP_ERROR); } if ((odmlockid = odm_lock("/etc/objrepos/config_lock", ODM_WAIT)) == -1) { @@ -387,13 +989,13 @@ bpf_odminit(char *errbuf) snprintf(errbuf, PCAP_ERRBUF_SIZE, "bpf_load: odm_lock of /etc/objrepos/config_lock failed: %s", errstr); - return (-1); + return (PCAP_ERROR); } return (0); } -static int +static int bpf_odmcleanup(char *errbuf) { char *errstr; @@ -404,7 +1006,7 @@ bpf_odmcleanup(char *errbuf) snprintf(errbuf, PCAP_ERRBUF_SIZE, "bpf_load: odm_unlock failed: %s", errstr); - return (-1); + return (PCAP_ERROR); } if (odm_terminate() == -1) { @@ -413,7 +1015,7 @@ bpf_odmcleanup(char *errbuf) snprintf(errbuf, PCAP_ERRBUF_SIZE, "bpf_load: odm_terminate failed: %s", errstr); - return (-1); + return (PCAP_ERROR); } return (0); @@ -438,14 +1040,14 @@ bpf_load(char *errbuf) if (bpfloadedflag) return (0); - if (bpf_odminit(errbuf) != 0) - return (-1); + if (bpf_odminit(errbuf) == PCAP_ERROR) + return (PCAP_ERROR); major = genmajor(BPF_NAME); if (major == -1) { snprintf(errbuf, PCAP_ERRBUF_SIZE, "bpf_load: genmajor failed: %s", pcap_strerror(errno)); - return (-1); + return (PCAP_ERROR); } minors = getminor(major, &numminors, BPF_NAME); @@ -455,19 +1057,19 @@ bpf_load(char *errbuf) snprintf(errbuf, PCAP_ERRBUF_SIZE, "bpf_load: genminor failed: %s", pcap_strerror(errno)); - return (-1); + return (PCAP_ERROR); } } - if (bpf_odmcleanup(errbuf)) - return (-1); + if (bpf_odmcleanup(errbuf) == PCAP_ERROR) + return (PCAP_ERROR); rc = stat(BPF_NODE "0", &sbuf); if (rc == -1 && errno != ENOENT) { snprintf(errbuf, PCAP_ERRBUF_SIZE, "bpf_load: can't stat %s: %s", BPF_NODE "0", pcap_strerror(errno)); - return (-1); + return (PCAP_ERROR); } if (rc == -1 || getmajor(sbuf.st_rdev) != major) { @@ -478,7 +1080,7 @@ bpf_load(char *errbuf) snprintf(errbuf, PCAP_ERRBUF_SIZE, "bpf_load: can't mknod %s: %s", buf, pcap_strerror(errno)); - return (-1); + return (PCAP_ERROR); } } } @@ -494,7 +1096,7 @@ bpf_load(char *errbuf) snprintf(errbuf, PCAP_ERRBUF_SIZE, "bpf_load: could not load driver: %s", strerror(errno)); - return (-1); + return (PCAP_ERROR); } } @@ -502,190 +1104,507 @@ bpf_load(char *errbuf) cfg_km.cmd = CFG_INIT; cfg_km.kmid = cfg_ld.kmid; cfg_km.mdilen = sizeof(cfg_bpf); - cfg_km.mdiptr = (void *)&cfg_bpf; + cfg_km.mdiptr = (void *)&cfg_bpf; for (i = 0; i < BPF_MINORS; i++) { cfg_bpf.devno = domakedev(major, i); if (sysconfig(SYS_CFGKMOD, (void *)&cfg_km, sizeof(cfg_km)) == -1) { snprintf(errbuf, PCAP_ERRBUF_SIZE, "bpf_load: could not configure driver: %s", strerror(errno)); - return (-1); + return (PCAP_ERROR); } } - + bpfloadedflag = 1; return (0); } #endif -static inline int -bpf_open(pcap_t *p, char *errbuf) +/* + * Turn off rfmon mode if necessary. + */ +static void +pcap_cleanup_bpf(pcap_t *p) { - int fd; -#ifdef HAVE_CLONING_BPF - static const char device[] = "/dev/bpf"; -#else - int n = 0; - char device[sizeof "/dev/bpf0000000000"]; +#ifdef HAVE_BSD_IEEE80211 + int sock; + struct ifmediareq req; + struct ifreq ifr; #endif -#ifdef _AIX - /* - * Load the bpf driver, if it isn't already loaded, - * and create the BPF device entries, if they don't - * already exist. - */ - if (bpf_load(errbuf) == -1) - return (-1); -#endif + if (p->md.must_clear != 0) { + /* + * There's something we have to do when closing this + * pcap_t. + */ +#ifdef HAVE_BSD_IEEE80211 + if (p->md.must_clear & MUST_CLEAR_RFMON) { + /* + * We put the interface into rfmon mode; + * take it out of rfmon mode. + * + * XXX - if somebody else wants it in rfmon + * mode, this code cannot know that, so it'll take + * it out of rfmon mode. + */ + sock = socket(AF_INET, SOCK_DGRAM, 0); + if (sock == -1) { + fprintf(stderr, + "Can't restore interface flags (socket() failed: %s).\n" + "Please adjust manually.\n", + strerror(errno)); + } else { + memset(&req, 0, sizeof(req)); + strncpy(req.ifm_name, p->md.device, + sizeof(req.ifm_name)); + if (ioctl(sock, SIOCGIFMEDIA, &req) < 0) { + fprintf(stderr, + "Can't restore interface flags (SIOCGIFMEDIA failed: %s).\n" + "Please adjust manually.\n", + strerror(errno)); + } else { + if (req.ifm_current & IFM_IEEE80211_MONITOR) { + /* + * Rfmon mode is currently on; + * turn it off. + */ + memset(&ifr, 0, sizeof(ifr)); + (void)strncpy(ifr.ifr_name, + p->md.device, + sizeof(ifr.ifr_name)); + ifr.ifr_media = + req.ifm_current & ~IFM_IEEE80211_MONITOR; + if (ioctl(sock, SIOCSIFMEDIA, + &ifr) == -1) { + fprintf(stderr, + "Can't restore interface flags (SIOCSIFMEDIA failed: %s).\n" + "Please adjust manually.\n", + strerror(errno)); + } + } + } + close(sock); + } + } +#endif /* HAVE_BSD_IEEE80211 */ -#ifdef HAVE_CLONING_BPF - if ((fd = open(device, O_RDWR)) == -1 && - (errno != EACCES || (fd = open(device, O_RDONLY)) == -1)) - snprintf(errbuf, PCAP_ERRBUF_SIZE, - "(cannot open device) %s: %s", device, pcap_strerror(errno)); -#else - /* - * Go through all the minors and find one that isn't in use. - */ - do { - (void)snprintf(device, sizeof(device), "/dev/bpf%d", n++); /* - * Initially try a read/write open (to allow the inject - * method to work). If that fails due to permission - * issues, fall back to read-only. This allows a - * non-root user to be granted specific access to pcap - * capabilities via file permissions. - * - * XXX - we should have an API that has a flag that - * controls whether to open read-only or read-write, - * so that denial of permission to send (or inability - * to send, if sending packets isn't supported on - * the device in question) can be indicated at open - * time. + * Take this pcap out of the list of pcaps for which we + * have to take the interface out of some mode. */ - fd = open(device, O_RDWR); - if (fd == -1 && errno == EACCES) - fd = open(device, O_RDONLY); - } while (fd < 0 && errno == EBUSY); + pcap_remove_from_pcaps_to_close(p); + p->md.must_clear = 0; + } +#ifdef HAVE_ZEROCOPY_BPF /* - * XXX better message for all minors used + * In zero-copy mode, p->buffer is just a pointer into one of the two + * memory-mapped buffers, so no need to free it. */ - if (fd < 0) - snprintf(errbuf, PCAP_ERRBUF_SIZE, "(no devices found) %s: %s", - device, pcap_strerror(errno)); + if (p->md.zerocopy) { + if (p->md.zbuf1 != MAP_FAILED && p->md.zbuf1 != NULL) + munmap(p->md.zbuf1, p->md.zbufsize); + if (p->md.zbuf2 != MAP_FAILED && p->md.zbuf2 != NULL) + munmap(p->md.zbuf2, p->md.zbufsize); + } #endif - - return (fd); + if (p->md.device != NULL) { + free(p->md.device); + p->md.device = NULL; + } + pcap_cleanup_live_common(p); } -/* - * We include the OS's <net/bpf.h>, not our "pcap-bpf.h", so we probably - * don't get DLT_DOCSIS defined. - */ -#ifndef DLT_DOCSIS -#define DLT_DOCSIS 143 +static int +check_setif_failure(pcap_t *p, int error) +{ +#ifdef __APPLE__ + int fd; + struct ifreq ifr; + int err; #endif -pcap_t * -pcap_open_live(const char *device, int snaplen, int promisc, int to_ms, - char *ebuf) + if (error == ENXIO) { + /* + * No such device exists. + */ +#ifdef __APPLE__ + if (p->opt.rfmon && strncmp(p->opt.source, "wlt", 3) == 0) { + /* + * Monitor mode was requested, and we're trying + * to open a "wltN" device. Assume that this + * is 10.4 and that we were asked to open an + * "enN" device; if that device exists, return + * "monitor mode not supported on the device". + */ + fd = socket(AF_INET, SOCK_DGRAM, 0); + if (fd != -1) { + strlcpy(ifr.ifr_name, "en", + sizeof(ifr.ifr_name)); + strlcat(ifr.ifr_name, p->opt.source + 3, + sizeof(ifr.ifr_name)); + if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) { + /* + * We assume this failed because + * the underlying device doesn't + * exist. + */ + err = PCAP_ERROR_NO_SUCH_DEVICE; + strcpy(p->errbuf, ""); + } else { + /* + * The underlying "enN" device + * exists, but there's no + * corresponding "wltN" device; + * that means that the "enN" + * device doesn't support + * monitor mode, probably because + * it's an Ethernet device rather + * than a wireless device. + */ + err = PCAP_ERROR_RFMON_NOTSUP; + } + close(fd); + } else { + /* + * We can't find out whether there's + * an underlying "enN" device, so + * just report "no such device". + */ + err = PCAP_ERROR_NO_SUCH_DEVICE; + strcpy(p->errbuf, ""); + } + return (err); + } +#endif + /* + * No such device. + */ + strcpy(p->errbuf, ""); + return (PCAP_ERROR_NO_SUCH_DEVICE); + } else if (errno == ENETDOWN) { + /* + * Return a "network down" indication, so that + * the application can report that rather than + * saying we had a mysterious failure and + * suggest that they report a problem to the + * libpcap developers. + */ + return (PCAP_ERROR_IFACE_NOT_UP); + } else { + /* + * Some other error; fill in the error string, and + * return PCAP_ERROR. + */ + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETIF: %s: %s", + p->opt.source, pcap_strerror(errno)); + return (PCAP_ERROR); + } +} + +static int +pcap_activate_bpf(pcap_t *p) { + int status = 0; int fd; struct ifreq ifr; struct bpf_version bv; +#ifdef __APPLE__ + int sockfd; + char *wltdev = NULL; +#endif #ifdef BIOCGDLTLIST struct bpf_dltlist bdl; +#if defined(__APPLE__) || defined(HAVE_BSD_IEEE80211) + int new_dlt; #endif +#endif /* BIOCGDLTLIST */ #if defined(BIOCGHDRCMPLT) && defined(BIOCSHDRCMPLT) u_int spoof_eth_src = 1; #endif u_int v; - pcap_t *p; struct bpf_insn total_insn; struct bpf_program total_prog; struct utsname osinfo; - -#ifdef HAVE_DAG_API - if (strstr(device, "dag")) { - return dag_open_live(device, snaplen, promisc, to_ms, ebuf); - } -#endif /* HAVE_DAG_API */ - -#ifdef BIOCGDLTLIST - memset(&bdl, 0, sizeof(bdl)); + int have_osinfo = 0; +#ifdef HAVE_ZEROCOPY_BPF + struct bpf_zbuf bz; + u_int bufmode, zbufmax; #endif - p = (pcap_t *)malloc(sizeof(*p)); - if (p == NULL) { - snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s", - pcap_strerror(errno)); - return (NULL); - } - memset(p, 0, sizeof(*p)); - fd = bpf_open(p, ebuf); - if (fd < 0) + fd = bpf_open(p); + if (fd < 0) { + status = fd; goto bad; + } p->fd = fd; - p->snapshot = snaplen; if (ioctl(fd, BIOCVERSION, (caddr_t)&bv) < 0) { - snprintf(ebuf, PCAP_ERRBUF_SIZE, "BIOCVERSION: %s", + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCVERSION: %s", pcap_strerror(errno)); + status = PCAP_ERROR; goto bad; } if (bv.bv_major != BPF_MAJOR_VERSION || bv.bv_minor < BPF_MINOR_VERSION) { - snprintf(ebuf, PCAP_ERRBUF_SIZE, + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "kernel bpf filter out of date"); + status = PCAP_ERROR; + goto bad; + } + + p->md.device = strdup(p->opt.source); + if (p->md.device == NULL) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "strdup: %s", + pcap_strerror(errno)); + status = PCAP_ERROR; goto bad; } /* - * Try finding a good size for the buffer; 32768 may be too - * big, so keep cutting it in half until we find a size - * that works, or run out of sizes to try. If the default - * is larger, don't make it smaller. - * - * XXX - there should be a user-accessible hook to set the - * initial buffer size. + * Attempt to find out the version of the OS on which we're running. + */ + if (uname(&osinfo) == 0) + have_osinfo = 1; + +#ifdef __APPLE__ + /* + * See comment in pcap_can_set_rfmon_bpf() for an explanation + * of why we check the version number. + */ + if (p->opt.rfmon) { + if (have_osinfo) { + /* + * We assume osinfo.sysname is "Darwin", because + * __APPLE__ is defined. We just check the version. + */ + if (osinfo.release[0] < '8' && + osinfo.release[1] == '.') { + /* + * 10.3 (Darwin 7.x) or earlier. + */ + status = PCAP_ERROR_RFMON_NOTSUP; + goto bad; + } + if (osinfo.release[0] == '8' && + osinfo.release[1] == '.') { + /* + * 10.4 (Darwin 8.x). s/en/wlt/ + */ + if (strncmp(p->opt.source, "en", 2) != 0) { + /* + * Not an enN device; check + * whether the device even exists. + */ + sockfd = socket(AF_INET, SOCK_DGRAM, 0); + if (sockfd != -1) { + strlcpy(ifr.ifr_name, + p->opt.source, + sizeof(ifr.ifr_name)); + if (ioctl(sockfd, SIOCGIFFLAGS, + (char *)&ifr) < 0) { + /* + * We assume this + * failed because + * the underlying + * device doesn't + * exist. + */ + status = PCAP_ERROR_NO_SUCH_DEVICE; + strcpy(p->errbuf, ""); + } else + status = PCAP_ERROR_RFMON_NOTSUP; + close(sockfd); + } else { + /* + * We can't find out whether + * the device exists, so just + * report "no such device". + */ + status = PCAP_ERROR_NO_SUCH_DEVICE; + strcpy(p->errbuf, ""); + } + goto bad; + } + wltdev = malloc(strlen(p->opt.source) + 2); + if (wltdev == NULL) { + (void)snprintf(p->errbuf, + PCAP_ERRBUF_SIZE, "malloc: %s", + pcap_strerror(errno)); + status = PCAP_ERROR; + goto bad; + } + strcpy(wltdev, "wlt"); + strcat(wltdev, p->opt.source + 2); + free(p->opt.source); + p->opt.source = wltdev; + } + /* + * Everything else is 10.5 or later; for those, + * we just open the enN device, and set the DLT. + */ + } + } +#endif /* __APPLE__ */ +#ifdef HAVE_ZEROCOPY_BPF + /* + * If the BPF extension to set buffer mode is present, try setting + * the mode to zero-copy. If that fails, use regular buffering. If + * it succeeds but other setup fails, return an error to the user. */ - if ((ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) || v < 32768) - v = 32768; - for ( ; v != 0; v >>= 1) { - /* Ignore the return value - this is because the call fails - * on BPF systems that don't have kernel malloc. And if - * the call fails, it's no big deal, we just continue to - * use the standard buffer size. + bufmode = BPF_BUFMODE_ZBUF; + if (ioctl(fd, BIOCSETBUFMODE, (caddr_t)&bufmode) == 0) { + /* + * We have zerocopy BPF; use it. + */ + p->md.zerocopy = 1; + + /* + * Set the cleanup and set/get nonblocking mode ops + * as appropriate for zero-copy mode. */ - (void) ioctl(fd, BIOCSBLEN, (caddr_t)&v); + p->cleanup_op = pcap_cleanup_zbuf; + p->setnonblock_op = pcap_setnonblock_zbuf; + p->getnonblock_op = pcap_getnonblock_zbuf; - (void)strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name)); - if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) >= 0) - break; /* that size worked; we're done */ + /* + * How to pick a buffer size: first, query the maximum buffer + * size supported by zero-copy. This also lets us quickly + * determine whether the kernel generally supports zero-copy. + * Then, if a buffer size was specified, use that, otherwise + * query the default buffer size, which reflects kernel + * policy for a desired default. Round to the nearest page + * size. + */ + if (ioctl(fd, BIOCGETZMAX, (caddr_t)&zbufmax) < 0) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGETZMAX: %s", + pcap_strerror(errno)); + goto bad; + } - if (errno != ENOBUFS) { - snprintf(ebuf, PCAP_ERRBUF_SIZE, "BIOCSETIF: %s: %s", - device, pcap_strerror(errno)); + if (p->opt.buffer_size != 0) { + /* + * A buffer size was explicitly specified; use it. + */ + v = p->opt.buffer_size; + } else { + if ((ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) || + v < 32768) + v = 32768; + } +#ifndef roundup +#define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */ +#endif + p->md.zbufsize = roundup(v, getpagesize()); + if (p->md.zbufsize > zbufmax) + p->md.zbufsize = zbufmax; + p->md.zbuf1 = mmap(NULL, p->md.zbufsize, PROT_READ | PROT_WRITE, + MAP_ANON, -1, 0); + p->md.zbuf2 = mmap(NULL, p->md.zbufsize, PROT_READ | PROT_WRITE, + MAP_ANON, -1, 0); + if (p->md.zbuf1 == MAP_FAILED || p->md.zbuf2 == MAP_FAILED) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "mmap: %s", + pcap_strerror(errno)); goto bad; } - } + bzero(&bz, sizeof(bz)); + bz.bz_bufa = p->md.zbuf1; + bz.bz_bufb = p->md.zbuf2; + bz.bz_buflen = p->md.zbufsize; + if (ioctl(fd, BIOCSETZBUF, (caddr_t)&bz) < 0) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETZBUF: %s", + pcap_strerror(errno)); + goto bad; + } + (void)strncpy(ifr.ifr_name, p->opt.source, sizeof(ifr.ifr_name)); + if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) < 0) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETIF: %s: %s", + p->opt.source, pcap_strerror(errno)); + goto bad; + } + v = p->md.zbufsize - sizeof(struct bpf_zbuf_header); + } else +#endif + { + /* + * We don't have zerocopy BPF. + * Set the buffer size. + */ + if (p->opt.buffer_size != 0) { + /* + * A buffer size was explicitly specified; use it. + */ + if (ioctl(fd, BIOCSBLEN, + (caddr_t)&p->opt.buffer_size) < 0) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "BIOCSBLEN: %s: %s", p->opt.source, + pcap_strerror(errno)); + status = PCAP_ERROR; + goto bad; + } - if (v == 0) { - snprintf(ebuf, PCAP_ERRBUF_SIZE, - "BIOCSBLEN: %s: No buffer size worked", device); - goto bad; + /* + * Now bind to the device. + */ + (void)strncpy(ifr.ifr_name, p->opt.source, + sizeof(ifr.ifr_name)); + if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) < 0) { + status = check_setif_failure(p, errno); + goto bad; + } + } else { + /* + * No buffer size was explicitly specified. + * + * Try finding a good size for the buffer; 32768 may + * be too big, so keep cutting it in half until we + * find a size that works, or run out of sizes to try. + * If the default is larger, don't make it smaller. + */ + if ((ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) || + v < 32768) + v = 32768; + for ( ; v != 0; v >>= 1) { + /* + * Ignore the return value - this is because the + * call fails on BPF systems that don't have + * kernel malloc. And if the call fails, it's + * no big deal, we just continue to use the + * standard buffer size. + */ + (void) ioctl(fd, BIOCSBLEN, (caddr_t)&v); + + (void)strncpy(ifr.ifr_name, p->opt.source, + sizeof(ifr.ifr_name)); + if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) >= 0) + break; /* that size worked; we're done */ + + if (errno != ENOBUFS) { + status = check_setif_failure(p, errno); + goto bad; + } + } + + if (v == 0) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "BIOCSBLEN: %s: No buffer size worked", + p->opt.source); + status = PCAP_ERROR; + goto bad; + } + } } /* Get the data link layer type. */ if (ioctl(fd, BIOCGDLT, (caddr_t)&v) < 0) { - snprintf(ebuf, PCAP_ERRBUF_SIZE, "BIOCGDLT: %s", + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGDLT: %s", pcap_strerror(errno)); + status = PCAP_ERROR; goto bad; } + #ifdef _AIX /* * AIX's BPF returns IFF_ types, not DLT_ types, in BIOCGDLT. @@ -713,8 +1632,9 @@ pcap_open_live(const char *device, int snaplen, int promisc, int to_ms, /* * We don't know what to map this to yet. */ - snprintf(ebuf, PCAP_ERRBUF_SIZE, "unknown interface type %u", + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "unknown interface type %u", v); + status = PCAP_ERROR; goto bad; } #endif @@ -739,13 +1659,6 @@ pcap_open_live(const char *device, int snaplen, int promisc, int to_ms, break; } #endif -#ifdef PCAP_FDDIPAD - if (v == DLT_FDDI) - p->fddipad = PCAP_FDDIPAD; - else - p->fddipad = 0; -#endif - p->linktype = v; #ifdef BIOCGDLTLIST /* @@ -753,68 +1666,144 @@ pcap_open_live(const char *device, int snaplen, int promisc, int to_ms, * this interface supports. If this fails with EINVAL, it's * not fatal; we just don't get to use the feature later. */ - if (ioctl(fd, BIOCGDLTLIST, (caddr_t)&bdl) == 0) { - u_int i; - int is_ethernet; + if (get_dlt_list(fd, v, &bdl, p->errbuf) == -1) { + status = PCAP_ERROR; + goto bad; + } + p->dlt_count = bdl.bfl_len; + p->dlt_list = bdl.bfl_list; - bdl.bfl_list = (u_int *) malloc(sizeof(u_int) * (bdl.bfl_len + 1)); - if (bdl.bfl_list == NULL) { - (void)snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s", - pcap_strerror(errno)); - goto bad; +#ifdef __APPLE__ + /* + * Monitor mode fun, continued. + * + * For 10.5 and, we're assuming, later releases, as noted above, + * 802.1 adapters that support monitor mode offer both DLT_EN10MB, + * DLT_IEEE802_11, and possibly some 802.11-plus-radio-information + * DLT_ value. Choosing one of the 802.11 DLT_ values will turn + * monitor mode on. + * + * Therefore, if the user asked for monitor mode, we filter out + * the DLT_EN10MB value, as you can't get that in monitor mode, + * and, if the user didn't ask for monitor mode, we filter out + * the 802.11 DLT_ values, because selecting those will turn + * monitor mode on. Then, for monitor mode, if an 802.11-plus- + * radio DLT_ value is offered, we try to select that, otherwise + * we try to select DLT_IEEE802_11. + */ + if (have_osinfo) { + if (isdigit((unsigned)osinfo.release[0]) && + (osinfo.release[0] == '9' || + isdigit((unsigned)osinfo.release[1]))) { + /* + * 10.5 (Darwin 9.x), or later. + */ + new_dlt = find_802_11(&bdl); + if (new_dlt != -1) { + /* + * We have at least one 802.11 DLT_ value, + * so this is an 802.11 interface. + * new_dlt is the best of the 802.11 + * DLT_ values in the list. + */ + if (p->opt.rfmon) { + /* + * Our caller wants monitor mode. + * Purge DLT_EN10MB from the list + * of link-layer types, as selecting + * it will keep monitor mode off. + */ + remove_en(p); + + /* + * If the new mode we want isn't + * the default mode, attempt to + * select the new mode. + */ + if (new_dlt != v) { + if (ioctl(p->fd, BIOCSDLT, + &new_dlt) != -1) { + /* + * We succeeded; + * make this the + * new DLT_ value. + */ + v = new_dlt; + } + } + } else { + /* + * Our caller doesn't want + * monitor mode. Unless this + * is being done by pcap_open_live(), + * purge the 802.11 link-layer types + * from the list, as selecting + * one of them will turn monitor + * mode on. + */ + if (!p->oldstyle) + remove_802_11(p); + } + } else { + if (p->opt.rfmon) { + /* + * The caller requested monitor + * mode, but we have no 802.11 + * link-layer types, so they + * can't have it. + */ + status = PCAP_ERROR_RFMON_NOTSUP; + goto bad; + } + } } - - if (ioctl(fd, BIOCGDLTLIST, (caddr_t)&bdl) < 0) { - (void)snprintf(ebuf, PCAP_ERRBUF_SIZE, - "BIOCGDLTLIST: %s", pcap_strerror(errno)); - free(bdl.bfl_list); + } +#elif defined(HAVE_BSD_IEEE80211) + /* + * *BSD with the new 802.11 ioctls. + * Do we want monitor mode? + */ + if (p->opt.rfmon) { + /* + * Try to put the interface into monitor mode. + */ + status = monitor_mode(p, 1); + if (status != 0) { + /* + * We failed. + */ goto bad; } /* - * OK, for real Ethernet devices, add DLT_DOCSIS to the - * list, so that an application can let you choose it, - * in case you're capturing DOCSIS traffic that a Cisco - * Cable Modem Termination System is putting out onto - * an Ethernet (it doesn't put an Ethernet header onto - * the wire, it puts raw DOCSIS frames out on the wire - * inside the low-level Ethernet framing). - * - * A "real Ethernet device" is defined here as a device - * that has a link-layer type of DLT_EN10MB and that has - * no alternate link-layer types; that's done to exclude - * 802.11 interfaces (which might or might not be the - * right thing to do, but I suspect it is - Ethernet <-> - * 802.11 bridges would probably badly mishandle frames - * that don't have Ethernet headers). + * We're in monitor mode. + * Try to find the best 802.11 DLT_ value and, if we + * succeed, try to switch to that mode if we're not + * already in that mode. */ - if (p->linktype == DLT_EN10MB) { - is_ethernet = 1; - for (i = 0; i < bdl.bfl_len; i++) { - if (bdl.bfl_list[i] != DLT_EN10MB) { - is_ethernet = 0; - break; + new_dlt = find_802_11(&bdl); + if (new_dlt != -1) { + /* + * We have at least one 802.11 DLT_ value. + * new_dlt is the best of the 802.11 + * DLT_ values in the list. + * + * If the new mode we want isn't the default mode, + * attempt to select the new mode. + */ + if (new_dlt != v) { + if (ioctl(p->fd, BIOCSDLT, &new_dlt) != -1) { + /* + * We succeeded; make this the + * new DLT_ value. + */ + v = new_dlt; } } - if (is_ethernet) { - /* - * We reserved one more slot at the end of - * the list. - */ - bdl.bfl_list[bdl.bfl_len] = DLT_DOCSIS; - bdl.bfl_len++; - } - } - p->dlt_count = bdl.bfl_len; - p->dlt_list = bdl.bfl_list; - } else { - if (errno != EINVAL) { - (void)snprintf(ebuf, PCAP_ERRBUF_SIZE, - "BIOCGDLTLIST: %s", pcap_strerror(errno)); - goto bad; } } -#endif +#endif /* various platforms */ +#endif /* BIOCGDLTLIST */ /* * If this is an Ethernet device, and we don't have a DLT_ list, @@ -824,7 +1813,7 @@ pcap_open_live(const char *device, int snaplen, int promisc, int to_ms, * some other way of determining whether it's an Ethernet or 802.11 * device.) */ - if (p->linktype == DLT_EN10MB && p->dlt_count == 0) { + if (v == DLT_EN10MB && p->dlt_count == 0) { p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2); /* * If that fails, just leave the list empty. @@ -835,7 +1824,14 @@ pcap_open_live(const char *device, int snaplen, int promisc, int to_ms, p->dlt_count = 2; } } - +#ifdef PCAP_FDDIPAD + if (v == DLT_FDDI) + p->fddipad = PCAP_FDDIPAD; + else + p->fddipad = 0; +#endif + p->linktype = v; + #if defined(BIOCGHDRCMPLT) && defined(BIOCSHDRCMPLT) /* * Do a BIOCSHDRCMPLT, if defined, to turn that flag on, so @@ -847,24 +1843,30 @@ pcap_open_live(const char *device, int snaplen, int promisc, int to_ms, * BSDs - check CVS log for "bpf.c"? */ if (ioctl(fd, BIOCSHDRCMPLT, &spoof_eth_src) == -1) { - (void)snprintf(ebuf, PCAP_ERRBUF_SIZE, + (void)snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSHDRCMPLT: %s", pcap_strerror(errno)); + status = PCAP_ERROR; goto bad; } #endif /* set timeout */ - if (to_ms != 0) { +#ifdef HAVE_ZEROCOPY_BPF + if (p->md.timeout != 0 && !p->md.zerocopy) { +#else + if (p->md.timeout) { +#endif /* * XXX - is this seconds/nanoseconds in AIX? * (Treating it as such doesn't fix the timeout * problem described below.) */ struct timeval to; - to.tv_sec = to_ms / 1000; - to.tv_usec = (to_ms * 1000) % 1000000; + to.tv_sec = p->md.timeout / 1000; + to.tv_usec = (p->md.timeout * 1000) % 1000000; if (ioctl(p->fd, BIOCSRTIMEOUT, (caddr_t)&to) < 0) { - snprintf(ebuf, PCAP_ERRBUF_SIZE, "BIOCSRTIMEOUT: %s", + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSRTIMEOUT: %s", pcap_strerror(errno)); + status = PCAP_ERROR; goto bad; } } @@ -919,38 +1921,48 @@ pcap_open_live(const char *device, int snaplen, int promisc, int to_ms, */ v = 1; if (ioctl(p->fd, BIOCIMMEDIATE, &v) < 0) { - snprintf(ebuf, PCAP_ERRBUF_SIZE, "BIOCIMMEDIATE: %s", + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCIMMEDIATE: %s", pcap_strerror(errno)); + status = PCAP_ERROR; goto bad; } #endif /* BIOCIMMEDIATE */ #endif /* _AIX */ - if (promisc) { - /* set promiscuous mode, okay if it fails */ + if (p->opt.promisc) { + /* set promiscuous mode, just warn if it fails */ if (ioctl(p->fd, BIOCPROMISC, NULL) < 0) { - snprintf(ebuf, PCAP_ERRBUF_SIZE, "BIOCPROMISC: %s", + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCPROMISC: %s", pcap_strerror(errno)); + status = PCAP_WARNING_PROMISC_NOTSUP; } } if (ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) { - snprintf(ebuf, PCAP_ERRBUF_SIZE, "BIOCGBLEN: %s", + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCGBLEN: %s", pcap_strerror(errno)); + status = PCAP_ERROR; goto bad; } p->bufsize = v; +#ifdef HAVE_ZEROCOPY_BPF + if (!p->md.zerocopy) { +#endif p->buffer = (u_char *)malloc(p->bufsize); if (p->buffer == NULL) { - snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s", + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "malloc: %s", pcap_strerror(errno)); + status = PCAP_ERROR; goto bad; } #ifdef _AIX - /* For some strange reason this seems to prevent the EFAULT + /* For some strange reason this seems to prevent the EFAULT * problems we have experienced from AIX BPF. */ memset(p->buffer, 0x0, p->bufsize); #endif +#ifdef HAVE_ZEROCOPY_BPF + } +#endif /* * If there's no filter program installed, there's @@ -964,13 +1976,14 @@ pcap_open_live(const char *device, int snaplen, int promisc, int to_ms, total_insn.code = (u_short)(BPF_RET | BPF_K); total_insn.jt = 0; total_insn.jf = 0; - total_insn.k = snaplen; + total_insn.k = p->snapshot; total_prog.bf_len = 1; total_prog.bf_insns = &total_insn; if (ioctl(p->fd, BIOCSETF, (caddr_t)&total_prog) < 0) { - snprintf(ebuf, PCAP_ERRBUF_SIZE, "BIOCSETF: %s", + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETF: %s", pcap_strerror(errno)); + status = PCAP_ERROR; goto bad; } @@ -1011,7 +2024,7 @@ pcap_open_live(const char *device, int snaplen, int promisc, int to_ms, * XXX - what about AIX? */ p->selectable_fd = p->fd; /* assume select() works until we know otherwise */ - if (uname(&osinfo) == 0) { + if (have_osinfo) { /* * We can check what OS this is. */ @@ -1030,15 +2043,12 @@ pcap_open_live(const char *device, int snaplen, int promisc, int to_ms, p->getnonblock_op = pcap_getnonblock_fd; p->setnonblock_op = pcap_setnonblock_fd; p->stats_op = pcap_stats_bpf; - p->close_op = pcap_close_common; + p->cleanup_op = pcap_cleanup_bpf; - return (p); + return (status); bad: - (void)close(fd); - if (p->dlt_list != NULL) - free(p->dlt_list); - free(p); - return (NULL); + pcap_cleanup_bpf(p); + return (status); } int @@ -1052,25 +2062,314 @@ pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf) return (0); } +#ifdef HAVE_BSD_IEEE80211 static int -pcap_setfilter_bpf(pcap_t *p, struct bpf_program *fp) +monitor_mode(pcap_t *p, int set) { + int sock; + struct ifmediareq req; + int *media_list; + int i; + int can_do; + struct ifreq ifr; + + sock = socket(AF_INET, SOCK_DGRAM, 0); + if (sock == -1) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "can't open socket: %s", + pcap_strerror(errno)); + return (PCAP_ERROR); + } + + memset(&req, 0, sizeof req); + strncpy(req.ifm_name, p->opt.source, sizeof req.ifm_name); + /* - * It looks that BPF code generated by gen_protochain() is not - * compatible with some of kernel BPF code (for example BSD/OS 3.1). - * Take a safer side for now. + * Find out how many media types we have. */ - if (no_optimize) { + if (ioctl(sock, SIOCGIFMEDIA, &req) < 0) { /* - * XXX - what if we already have a filter in the kernel? + * Can't get the media types. */ - if (install_bpf_program(p, fp) < 0) - return (-1); - p->md.use_bpf = 0; /* filtering in userland */ - return (0); + if (errno == EINVAL) { + /* + * Interface doesn't support SIOC{G,S}IFMEDIA. + */ + close(sock); + return (PCAP_ERROR_RFMON_NOTSUP); + } + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "SIOCGIFMEDIA 1: %s", + pcap_strerror(errno)); + close(sock); + return (PCAP_ERROR); + } + if (req.ifm_count == 0) { + /* + * No media types. + */ + close(sock); + return (PCAP_ERROR_RFMON_NOTSUP); + } + + /* + * Allocate a buffer to hold all the media types, and + * get the media types. + */ + media_list = malloc(req.ifm_count * sizeof(int)); + if (media_list == NULL) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "malloc: %s", + pcap_strerror(errno)); + close(sock); + return (PCAP_ERROR); + } + req.ifm_ulist = media_list; + if (ioctl(sock, SIOCGIFMEDIA, &req) < 0) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "SIOCGIFMEDIA: %s", + pcap_strerror(errno)); + free(media_list); + close(sock); + return (PCAP_ERROR); } /* + * Look for an 802.11 "automatic" media type. + * We assume that all 802.11 adapters have that media type, + * and that it will carry the monitor mode supported flag. + */ + can_do = 0; + for (i = 0; i < req.ifm_count; i++) { + if (IFM_TYPE(media_list[i]) == IFM_IEEE80211 + && IFM_SUBTYPE(media_list[i]) == IFM_AUTO) { + /* OK, does it do monitor mode? */ + if (media_list[i] & IFM_IEEE80211_MONITOR) { + can_do = 1; + break; + } + } + } + free(media_list); + if (!can_do) { + /* + * This adapter doesn't support monitor mode. + */ + close(sock); + return (PCAP_ERROR_RFMON_NOTSUP); + } + + if (set) { + /* + * Don't just check whether we can enable monitor mode, + * do so, if it's not already enabled. + */ + if ((req.ifm_current & IFM_IEEE80211_MONITOR) == 0) { + /* + * Monitor mode isn't currently on, so turn it on, + * and remember that we should turn it off when the + * pcap_t is closed. + */ + + /* + * If we haven't already done so, arrange to have + * "pcap_close_all()" called when we exit. + */ + if (!pcap_do_addexit(p)) { + /* + * "atexit()" failed; don't put the interface + * in monitor mode, just give up. + */ + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "atexit failed"); + close(sock); + return (PCAP_ERROR); + } + memset(&ifr, 0, sizeof(ifr)); + (void)strncpy(ifr.ifr_name, p->opt.source, + sizeof(ifr.ifr_name)); + ifr.ifr_media = req.ifm_current | IFM_IEEE80211_MONITOR; + if (ioctl(sock, SIOCSIFMEDIA, &ifr) == -1) { + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "SIOCSIFMEDIA: %s", pcap_strerror(errno)); + close(sock); + return (PCAP_ERROR); + } + + p->md.must_clear |= MUST_CLEAR_RFMON; + + /* + * Add this to the list of pcaps to close when we exit. + */ + pcap_add_to_pcaps_to_close(p); + } + } + return (0); +} +#endif /* HAVE_BSD_IEEE80211 */ + +#if defined(BIOCGDLTLIST) && (defined(__APPLE__) || defined(HAVE_BSD_IEEE80211)) +/* + * Check whether we have any 802.11 link-layer types; return the best + * of the 802.11 link-layer types if we find one, and return -1 + * otherwise. + * + * DLT_IEEE802_11_RADIO, with the radiotap header, is considered the + * best 802.11 link-layer type; any of the other 802.11-plus-radio + * headers are second-best; 802.11 with no radio information is + * the least good. + */ +static int +find_802_11(struct bpf_dltlist *bdlp) +{ + int new_dlt; + int i; + + /* + * Scan the list of DLT_ values, looking for 802.11 values, + * and, if we find any, choose the best of them. + */ + new_dlt = -1; + for (i = 0; i < bdlp->bfl_len; i++) { + switch (bdlp->bfl_list[i]) { + + case DLT_IEEE802_11: + /* + * 802.11, but no radio. + * + * Offer this, and select it as the new mode + * unless we've already found an 802.11 + * header with radio information. + */ + if (new_dlt == -1) + new_dlt = bdlp->bfl_list[i]; + break; + + case DLT_PRISM_HEADER: + case DLT_AIRONET_HEADER: + case DLT_IEEE802_11_RADIO_AVS: + /* + * 802.11 with radio, but not radiotap. + * + * Offer this, and select it as the new mode + * unless we've already found the radiotap DLT_. + */ + if (new_dlt != DLT_IEEE802_11_RADIO) + new_dlt = bdlp->bfl_list[i]; + break; + + case DLT_IEEE802_11_RADIO: + /* + * 802.11 with radiotap. + * + * Offer this, and select it as the new mode. + */ + new_dlt = bdlp->bfl_list[i]; + break; + + default: + /* + * Not 802.11. + */ + break; + } + } + + return (new_dlt); +} +#endif /* defined(BIOCGDLTLIST) && (defined(__APPLE__) || defined(HAVE_BSD_IEEE80211)) */ + +#if defined(__APPLE__) && defined(BIOCGDLTLIST) +/* + * Remove DLT_EN10MB from the list of DLT_ values. + */ +static void +remove_en(pcap_t *p) +{ + int i, j; + + /* + * Scan the list of DLT_ values and discard DLT_EN10MB. + */ + j = 0; + for (i = 0; i < p->dlt_count; i++) { + switch (p->dlt_list[i]) { + + case DLT_EN10MB: + /* + * Don't offer this one. + */ + continue; + + default: + /* + * Just copy this mode over. + */ + break; + } + + /* + * Copy this DLT_ value to its new position. + */ + p->dlt_list[j] = p->dlt_list[i]; + j++; + } + + /* + * Set the DLT_ count to the number of entries we copied. + */ + p->dlt_count = j; +} + +/* + * Remove DLT_EN10MB from the list of DLT_ values, and look for the + * best 802.11 link-layer type in that list and return it. + * Radiotap is better than anything else; 802.11 with any other radio + * header is better than 802.11 with no radio header. + */ +static void +remove_802_11(pcap_t *p) +{ + int i, j; + + /* + * Scan the list of DLT_ values and discard 802.11 values. + */ + j = 0; + for (i = 0; i < p->dlt_count; i++) { + switch (p->dlt_list[i]) { + + case DLT_IEEE802_11: + case DLT_PRISM_HEADER: + case DLT_AIRONET_HEADER: + case DLT_IEEE802_11_RADIO: + case DLT_IEEE802_11_RADIO_AVS: + /* + * 802.11. Don't offer this one. + */ + continue; + + default: + /* + * Just copy this mode over. + */ + break; + } + + /* + * Copy this DLT_ value to its new position. + */ + p->dlt_list[j] = p->dlt_list[i]; + j++; + } + + /* + * Set the DLT_ count to the number of entries we copied. + */ + p->dlt_count = j; +} +#endif /* defined(__APPLE__) && defined(BIOCGDLTLIST) */ + +static int +pcap_setfilter_bpf(pcap_t *p, struct bpf_program *fp) +{ + /* * Free any user-mode filter we might happen to have installed. */ pcap_freecode(&p->fcode); @@ -1078,20 +2377,51 @@ pcap_setfilter_bpf(pcap_t *p, struct bpf_program *fp) /* * Try to install the kernel filter. */ - if (ioctl(p->fd, BIOCSETF, (caddr_t)fp) < 0) { + if (ioctl(p->fd, BIOCSETF, (caddr_t)fp) == 0) { + /* + * It worked. + */ + p->md.use_bpf = 1; /* filtering in the kernel */ + + /* + * Discard any previously-received packets, as they might + * have passed whatever filter was formerly in effect, but + * might not pass this filter (BIOCSETF discards packets + * buffered in the kernel, so you can lose packets in any + * case). + */ + p->cc = 0; + return (0); + } + + /* + * We failed. + * + * If it failed with EINVAL, that's probably because the program + * is invalid or too big. Validate it ourselves; if we like it + * (we currently allow backward branches, to support protochain), + * run it in userland. (There's no notion of "too big" for + * userland.) + * + * Otherwise, just give up. + * XXX - if the copy of the program into the kernel failed, + * we will get EINVAL rather than, say, EFAULT on at least + * some kernels. + */ + if (errno != EINVAL) { snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETF: %s", pcap_strerror(errno)); return (-1); } - p->md.use_bpf = 1; /* filtering in the kernel */ /* - * Discard any previously-received packets, as they might have - * passed whatever filter was formerly in effect, but might - * not pass this filter (BIOCSETF discards packets buffered - * in the kernel, so you can lose packets in any case). + * install_bpf_program() validates the program. + * + * XXX - what if we already have a filter in the kernel? */ - p->cc = 0; + if (install_bpf_program(p, fp) < 0) + return (-1); + p->md.use_bpf = 0; /* filtering in userland */ return (0); } |