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author | Dag-Erling Smørgrav <des@FreeBSD.org> | 2004-01-07 11:10:17 +0000 |
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committer | Dag-Erling Smørgrav <des@FreeBSD.org> | 2004-01-07 11:10:17 +0000 |
commit | d95e11bf7e5a59b5c3f81bd8dfc2918ee7d3bada (patch) | |
tree | d7e09b6d73cb37aa875779151439b14df7273b87 /crypto/openssh/canohost.c | |
parent | dcf5581978ae9708715473af978f587c1ad7caf7 (diff) | |
download | src-test2-d95e11bf7e5a59b5c3f81bd8dfc2918ee7d3bada.tar.gz src-test2-d95e11bf7e5a59b5c3f81bd8dfc2918ee7d3bada.zip |
Notes
Diffstat (limited to 'crypto/openssh/canohost.c')
-rw-r--r-- | crypto/openssh/canohost.c | 52 |
1 files changed, 32 insertions, 20 deletions
diff --git a/crypto/openssh/canohost.c b/crypto/openssh/canohost.c index 941db23b64bf..438175f76866 100644 --- a/crypto/openssh/canohost.c +++ b/crypto/openssh/canohost.c @@ -12,7 +12,7 @@ */ #include "includes.h" -RCSID("$OpenBSD: canohost.c,v 1.35 2002/11/26 02:38:54 stevesk Exp $"); +RCSID("$OpenBSD: canohost.c,v 1.37 2003/06/02 09:17:34 markus Exp $"); #include "packet.h" #include "xmalloc.h" @@ -27,7 +27,7 @@ static void check_ip_options(int, char *); */ static char * -get_remote_hostname(int socket, int verify_reverse_mapping) +get_remote_hostname(int socket, int use_dns) { struct sockaddr_storage from; int i; @@ -72,6 +72,9 @@ get_remote_hostname(int socket, int verify_reverse_mapping) NULL, 0, NI_NUMERICHOST) != 0) fatal("get_remote_hostname: getnameinfo NI_NUMERICHOST failed"); + if (!use_dns) + return xstrdup(ntop); + if (from.ss_family == AF_INET) check_ip_options(socket, ntop); @@ -80,14 +83,24 @@ get_remote_hostname(int socket, int verify_reverse_mapping) if (getnameinfo((struct sockaddr *)&from, fromlen, name, sizeof(name), NULL, 0, NI_NAMEREQD) != 0) { /* Host name not found. Use ip address. */ -#if 0 - log("Could not reverse map address %.100s.", ntop); -#endif return xstrdup(ntop); } - /* Got host name. */ - name[sizeof(name) - 1] = '\0'; + /* + * if reverse lookup result looks like a numeric hostname, + * someone is trying to trick us by PTR record like following: + * 1.1.1.10.in-addr.arpa. IN PTR 2.3.4.5 + */ + memset(&hints, 0, sizeof(hints)); + hints.ai_socktype = SOCK_DGRAM; /*dummy*/ + hints.ai_flags = AI_NUMERICHOST; + if (getaddrinfo(name, "0", &hints, &ai) == 0) { + logit("Nasty PTR record \"%s\" is set up for %s, ignoring", + name, ntop); + freeaddrinfo(ai); + return xstrdup(ntop); + } + /* * Convert it to all lowercase (which is expected by the rest * of this software). @@ -95,9 +108,6 @@ get_remote_hostname(int socket, int verify_reverse_mapping) for (i = 0; name[i]; i++) if (isupper(name[i])) name[i] = tolower(name[i]); - - if (!verify_reverse_mapping) - return xstrdup(name); /* * Map it back to an IP address and check that the given * address actually is an address of this host. This is @@ -111,7 +121,7 @@ get_remote_hostname(int socket, int verify_reverse_mapping) hints.ai_family = from.ss_family; hints.ai_socktype = SOCK_STREAM; if (getaddrinfo(name, NULL, &hints, &aitop) != 0) { - log("reverse mapping checking getaddrinfo for %.700s " + logit("reverse mapping checking getaddrinfo for %.700s " "failed - POSSIBLE BREAKIN ATTEMPT!", name); return xstrdup(ntop); } @@ -126,7 +136,7 @@ get_remote_hostname(int socket, int verify_reverse_mapping) /* If we reached the end of the list, the address was not there. */ if (!ai) { /* Address not found for the host name. */ - log("Address %.100s maps to %.600s, but this does not " + logit("Address %.100s maps to %.600s, but this does not " "map back to the address - POSSIBLE BREAKIN ATTEMPT!", ntop, name); return xstrdup(ntop); @@ -149,6 +159,7 @@ get_remote_hostname(int socket, int verify_reverse_mapping) static void check_ip_options(int socket, char *ipaddr) { +#ifdef IP_OPTIONS u_char options[200]; char text[sizeof(options) * 3 + 1]; socklen_t option_size; @@ -166,11 +177,12 @@ check_ip_options(int socket, char *ipaddr) for (i = 0; i < option_size; i++) snprintf(text + i*3, sizeof(text) - i*3, " %2.2x", options[i]); - log("Connection from %.100s with IP options:%.800s", + logit("Connection from %.100s with IP options:%.800s", ipaddr, text); packet_disconnect("Connection from %.100s with IP options:%.800s", ipaddr, text); } +#endif /* IP_OPTIONS */ } /* @@ -180,14 +192,14 @@ check_ip_options(int socket, char *ipaddr) */ const char * -get_canonical_hostname(int verify_reverse_mapping) +get_canonical_hostname(int use_dns) { static char *canonical_host_name = NULL; - static int verify_reverse_mapping_done = 0; + static int use_dns_done = 0; /* Check if we have previously retrieved name with same option. */ if (canonical_host_name != NULL) { - if (verify_reverse_mapping_done != verify_reverse_mapping) + if (use_dns_done != use_dns) xfree(canonical_host_name); else return canonical_host_name; @@ -196,11 +208,11 @@ get_canonical_hostname(int verify_reverse_mapping) /* Get the real hostname if socket; otherwise return UNKNOWN. */ if (packet_connection_is_on_socket()) canonical_host_name = get_remote_hostname( - packet_get_connection_in(), verify_reverse_mapping); + packet_get_connection_in(), use_dns); else canonical_host_name = xstrdup("UNKNOWN"); - verify_reverse_mapping_done = verify_reverse_mapping; + use_dns_done = use_dns; return canonical_host_name; } @@ -294,11 +306,11 @@ get_remote_ipaddr(void) } const char * -get_remote_name_or_ip(u_int utmp_len, int verify_reverse_mapping) +get_remote_name_or_ip(u_int utmp_len, int use_dns) { static const char *remote = ""; if (utmp_len > 0) - remote = get_canonical_hostname(verify_reverse_mapping); + remote = get_canonical_hostname(use_dns); if (utmp_len == 0 || strlen(remote) > utmp_len) remote = get_remote_ipaddr(); return remote; |