From: Heiko Schlittermann (HS12-RIPE) Date: Fri, 2 Oct 2020 06:19:12 +0000 (+0200) Subject: Use ALARM() to set deadline on reading the proxy header (Bug 2656) X-Git-Url: https://git.exim.org/users/heiko/exim.git/commitdiff_plain/db889856a56c1da9d18fc2f676b4aad2d45dc585?ds=sidebyside Use ALARM() to set deadline on reading the proxy header (Bug 2656) --- diff --git a/src/src/macros.h b/src/src/macros.h index 82e50b5fe..c3f1c5d43 100644 --- a/src/src/macros.h +++ b/src/src/macros.h @@ -201,7 +201,6 @@ host isn't speaking the protocol, and so is disallowed. Can be moved to runtime configuration if per site settings become needed. */ #ifdef SUPPORT_PROXY #define PROXY_NEGOTIATION_TIMEOUT_SEC 3 -#define PROXY_NEGOTIATION_TIMEOUT_USEC 0 #endif /* Fixed option values for all PCRE functions */ diff --git a/src/src/smtp_in.c b/src/src/smtp_in.c index 39416679b..69eae3cb4 100644 --- a/src/src/smtp_in.c +++ b/src/src/smtp_in.c @@ -1033,25 +1033,6 @@ had_command_sigterm = sig; #ifdef SUPPORT_PROXY -/************************************************* -* Restore socket timeout to previous value * -*************************************************/ -/* If the previous value was successfully retrieved, restore -it before returning control to the non-proxy routines - -Arguments: fd - File descriptor for input - get_ok - Successfully retrieved previous values - tvtmp - Time struct with previous values - vslen - Length of time struct -Returns: none -*/ -static void -restore_socket_timeout(int fd, int get_ok, struct timeval * tvtmp, socklen_t vslen) -{ -if (get_ok == 0) - (void) setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, CS tvtmp, vslen); -} - /************************************************* * Check if host is required proxy host * *************************************************/ @@ -1128,7 +1109,7 @@ if (cr != NULL) while (capacity > 0) { - do { ret = read(fd, to, 1); } while (ret == -1 && errno == EINTR); + do { ret = read(fd, to, 1); } while (ret == -1 && errno == EINTR && !had_command_timeout); if (ret == -1) return -1; have++; @@ -1237,15 +1218,8 @@ struct timeval tvtmp; socklen_t vslen = sizeof(struct timeval); BOOL yield = FALSE; -/* Save current socket timeout values */ -get_ok = getsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, CS &tvtmp, &vslen); - -/* Proxy Protocol host must send header within a short time -(default 3 seconds) or it's considered invalid */ -tv.tv_sec = PROXY_NEGOTIATION_TIMEOUT_SEC; -tv.tv_usec = PROXY_NEGOTIATION_TIMEOUT_USEC; -if (setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, CS &tv, sizeof(tv)) < 0) - goto bad; +os_non_restarting_signal(SIGALRM, command_timeout_handler); +ALARM(PROXY_NEGOTIATION_TIMEOUT_SEC); do { @@ -1255,7 +1229,7 @@ do immediately with TLS handshake. */ ret = read(fd, &hdr, PROXY_INITIAL_READ); } - while (ret == -1 && errno == EINTR); + while (ret == -1 && errno == EINTR && !had_command_timeout); if (ret == -1) goto proxyfail; @@ -1270,7 +1244,7 @@ if ((ret == PROXY_INITIAL_READ) && (memcmp(&hdr.v2, v2sig, sizeof(v2sig)) == 0)) do { retmore = read(fd, (uschar*)&hdr + ret, PROXY_V2_HEADER_SIZE - PROXY_INITIAL_READ); - } while (retmore == -1 && errno == EINTR); + } while (retmore == -1 && errno == EINTR && !had_command_timeout); if (retmore == -1) goto proxyfail; ret += retmore; @@ -1307,7 +1281,7 @@ if ((ret == PROXY_INITIAL_READ) && (memcmp(&hdr.v2, v2sig, sizeof(v2sig)) == 0)) do { retmore = read(fd, (uschar*)&hdr + ret, size-ret); - } while (retmore == -1 && errno == EINTR); + } while (retmore == -1 && errno == EINTR && !had_command_timeout); if (retmore == -1) goto proxyfail; ret += retmore; @@ -1535,7 +1509,8 @@ done: should cause a synchronization failure */ proxyfail: - restore_socket_timeout(fd, get_ok, &tvtmp, vslen); + DEBUG(D_receive) if (had_command_timeout) + debug_printf("Timeout while reading proxy header\n"); bad: if (yield) @@ -1551,6 +1526,7 @@ bad: debug_printf("Failure to extract proxied host, only QUIT allowed\n"); } +ALARM(0); return; } #endif @@ -2412,7 +2388,7 @@ TCP_SYN_RCV (as of 12.1) so no idea about data-use. */ if (getsockopt(fileno(smtp_out), IPPROTO_TCP, TCP_FASTOPEN, &is_fastopen, &len) == 0) { - if (is_fastopen) + if (is_fastopen) { DEBUG(D_receive) debug_printf("TFO mode connection (TCP_FASTOPEN getsockopt)\n"); @@ -5769,7 +5745,7 @@ while (done <= 0) /* If not serializing, do the exec right away. Otherwise, fork down into another process. */ - if ( !smtp_etrn_serialize + if ( !smtp_etrn_serialize || (pid = exim_fork(US"etrn-serialised-command")) == 0) { DEBUG(D_exec) debug_print_argv(argv);