diff options
Diffstat (limited to 'lib/libalias/alias.c')
| -rw-r--r-- | lib/libalias/alias.c | 38 |
1 files changed, 28 insertions, 10 deletions
diff --git a/lib/libalias/alias.c b/lib/libalias/alias.c index a9c1e3b..c8ef65a 100644 --- a/lib/libalias/alias.c +++ b/lib/libalias/alias.c @@ -73,6 +73,8 @@ - Eliminated PacketAliasIn2() and PacketAliasOut2() as poorly conceived. + See HISTORY file for additional revisions. + */ #include <stdio.h> @@ -149,12 +151,15 @@ TcpMonitorIn(struct ip *pip, struct alias_link *link) switch (GetStateIn(link)) { - case 0: - if (tc->th_flags & TH_SYN) SetStateIn(link, 1); + case ALIAS_TCP_STATE_NOT_CONNECTED: + if (tc->th_flags & TH_SYN) + SetStateIn(link, ALIAS_TCP_STATE_CONNECTED); break; - case 1: + case ALIAS_TCP_STATE_CONNECTED: if (tc->th_flags & TH_FIN - || tc->th_flags & TH_RST) SetStateIn(link, 2); + || tc->th_flags & TH_RST) + SetStateIn(link, ALIAS_TCP_STATE_DISCONNECTED); + break; } } @@ -167,12 +172,15 @@ TcpMonitorOut(struct ip *pip, struct alias_link *link) switch (GetStateOut(link)) { - case 0: - if (tc->th_flags & TH_SYN) SetStateOut(link, 1); + case ALIAS_TCP_STATE_NOT_CONNECTED: + if (tc->th_flags & TH_SYN) + SetStateOut(link, ALIAS_TCP_STATE_CONNECTED); break; - case 1: + case ALIAS_TCP_STATE_CONNECTED: if (tc->th_flags & TH_FIN - || tc->th_flags & TH_RST) SetStateOut(link, 2); + || tc->th_flags & TH_RST) + SetStateOut(link, ALIAS_TCP_STATE_DISCONNECTED); + break; } } @@ -776,7 +784,7 @@ TcpAliasOut(struct ip *pip, int maxpacketsize) || ntohs(tc->th_sport) == FTP_CONTROL_PORT_NUMBER) AliasHandleFtpOut(pip, link, maxpacketsize); if (ntohs(tc->th_dport) == IRC_CONTROL_PORT_NUMBER_1 - || ntohs(tc->th_dport) == IRC_CONTROL_PORT_NUMBER_2) + || ntohs(tc->th_dport) == IRC_CONTROL_PORT_NUMBER_2) AliasHandleIrcOut(pip, link, maxpacketsize); /* Adjust TCP checksum since source port is being aliased */ @@ -977,6 +985,11 @@ PacketAliasIn(char *ptr, int maxpacketsize) pip = (struct ip *) ptr; alias_addr = pip->ip_dst; + /* Defense against mangled packets */ + if (ntohs(pip->ip_len) > maxpacketsize + || (pip->ip_hl<<2) > maxpacketsize) + return PKT_ALIAS_IGNORED; + iresult = PKT_ALIAS_IGNORED; if ( (ntohs(pip->ip_off) & IP_OFFMASK) == 0 ) { @@ -1002,7 +1015,7 @@ PacketAliasIn(char *ptr, int maxpacketsize) { iresult = PKT_ALIAS_FOUND_HEADER_FRAGMENT; SetFragmentAddr(link, pip->ip_dst); - } + } else { iresult = PKT_ALIAS_ERROR; @@ -1049,6 +1062,11 @@ PacketAliasOut(char *ptr, /* valid IP packet */ ClearCheckNewLink(); pip = (struct ip *) ptr; + /* Defense against mangled packets */ + if (ntohs(pip->ip_len) > maxpacketsize + || (pip->ip_hl<<2) > maxpacketsize) + return PKT_ALIAS_IGNORED; + addr_save = GetDefaultAliasAddress(); if (packetAliasMode & PKT_ALIAS_UNREGISTERED_ONLY) { |
