masqmail

annotate src/listen.c @ 206:0241aaccfcdb

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default listen_addresses: use 127.0.0.1 instead of `localhost' because `localhost' could be bound to some other IP address. This is unlikely but could be. Using 127.0.0.1 is more safe. See mailing list for details
author meillo@marmaro.de
date Sat, 17 Jul 2010 00:34:40 +0200
parents f671821d8222
children dcb315792513
rev   line source
meillo@0 1 /* MasqMail
meillo@0 2 Copyright (C) 1999/2000 Oliver Kurth
meillo@0 3
meillo@0 4 This program is free software; you can redistribute it and/or modify
meillo@0 5 it under the terms of the GNU General Public License as published by
meillo@0 6 the Free Software Foundation; either version 2 of the License, or
meillo@0 7 (at your option) any later version.
meillo@0 8
meillo@0 9 This program is distributed in the hope that it will be useful,
meillo@0 10 but WITHOUT ANY WARRANTY; without even the implied warranty of
meillo@0 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
meillo@0 12 GNU General Public License for more details.
meillo@0 13
meillo@0 14 You should have received a copy of the GNU General Public License
meillo@0 15 along with this program; if not, write to the Free Software
meillo@0 16 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
meillo@0 17 */
meillo@0 18
meillo@0 19 #include <sys/wait.h>
meillo@0 20 #include <sys/types.h>
meillo@0 21
meillo@15 22 #include "masqmail.h"
meillo@15 23
meillo@0 24 static int volatile sighup_seen = 0;
meillo@0 25
meillo@10 26 static void
meillo@10 27 sighup_handler(int sig)
meillo@0 28 {
meillo@10 29 sighup_seen = 1;
meillo@10 30 signal(SIGHUP, sighup_handler);
meillo@0 31 }
meillo@0 32
meillo@10 33 static void
meillo@10 34 sigchld_handler(int sig)
meillo@0 35 {
meillo@10 36 pid_t pid;
meillo@10 37 int status;
meillo@10 38
meillo@10 39 pid = waitpid(0, &status, 0);
meillo@10 40 if (pid > 0) {
meillo@10 41 if (WEXITSTATUS(status) != EXIT_SUCCESS)
meillo@10 42 logwrite(LOG_WARNING, "process %d exited with %d\n", pid, WEXITSTATUS(status));
meillo@10 43 if (WIFSIGNALED(status))
meillo@10 44 logwrite(LOG_WARNING, "process with pid %d got signal: %d\n", pid, WTERMSIG(status));
meillo@10 45 }
meillo@10 46 signal(SIGCHLD, sigchld_handler);
meillo@0 47 }
meillo@0 48
meillo@10 49 void
meillo@10 50 accept_connect(int listen_sock, int sock, struct sockaddr_in *sock_addr)
meillo@0 51 {
meillo@10 52 pid_t pid;
meillo@10 53 int dup_sock = dup(sock);
meillo@10 54 FILE *out, *in;
meillo@10 55 gchar *rem_host;
meillo@10 56 gchar *ident = NULL;
meillo@0 57
meillo@10 58 rem_host = g_strdup(inet_ntoa(sock_addr->sin_addr));
meillo@0 59 #ifdef ENABLE_IDENT
meillo@10 60 {
meillo@10 61 gchar *id = NULL;
meillo@10 62 if ((id = (gchar *) ident_id(sock, 60))) {
meillo@10 63 ident = g_strdup(id);
meillo@10 64 }
meillo@10 65 logwrite(LOG_NOTICE, "connect from host %s, port %hd ident=%s\n", rem_host,
meillo@10 66 ntohs(sock_addr->sin_port), ident ? ident : "(unknown)");
meillo@10 67 }
meillo@0 68 #else
meillo@10 69 logwrite(LOG_NOTICE, "connect from host %s, port %hd\n", rem_host, ntohs(sock_addr->sin_port));
meillo@0 70 #endif
meillo@0 71
meillo@10 72 // start child for connection:
meillo@10 73 signal(SIGCHLD, sigchld_handler);
meillo@10 74 pid = fork();
meillo@10 75 if (pid == 0) {
meillo@10 76 close(listen_sock);
meillo@10 77 out = fdopen(sock, "w");
meillo@10 78 in = fdopen(dup_sock, "r");
meillo@0 79
meillo@10 80 smtp_in(in, out, rem_host, ident);
meillo@0 81
meillo@10 82 _exit(EXIT_SUCCESS);
meillo@10 83 } else if (pid < 0) {
meillo@10 84 logwrite(LOG_WARNING, "could not fork for incoming smtp connection: %s\n", strerror(errno));
meillo@10 85 }
meillo@0 86 #ifdef ENABLE_IDENT
meillo@10 87 if (ident != NULL)
meillo@10 88 g_free(ident);
meillo@0 89 #endif
meillo@0 90
meillo@10 91 close(sock);
meillo@10 92 close(dup_sock);
meillo@0 93 }
meillo@0 94
meillo@10 95 void
meillo@10 96 listen_port(GList * iface_list, gint qival, char *argv[])
meillo@0 97 {
meillo@10 98 int i;
meillo@10 99 fd_set active_fd_set, read_fd_set;
meillo@10 100 struct timeval tm;
meillo@10 101 time_t time_before, time_now;
meillo@10 102 struct sockaddr_in clientname;
meillo@10 103 size_t size;
meillo@10 104 GList *node, *node_next;
meillo@10 105 int sel_ret;
meillo@0 106
meillo@10 107 /* Create the sockets and set them up to accept connections. */
meillo@10 108 FD_ZERO(&active_fd_set);
meillo@10 109 for (node = g_list_first(iface_list); node; node = node_next) {
meillo@10 110 interface *iface = (interface *) (node->data);
meillo@10 111 int sock;
meillo@0 112
meillo@10 113 node_next = g_list_next(node);
meillo@10 114 if ((sock = make_server_socket(iface)) < 0) {
meillo@10 115 iface_list = g_list_remove_link(iface_list, node);
meillo@10 116 g_list_free_1(node);
meillo@10 117 continue;
meillo@10 118 }
meillo@10 119 if (listen(sock, 1) < 0) {
meillo@10 120 logwrite(LOG_ALERT, "listen: (terminating): %s\n", strerror(errno));
meillo@10 121 exit(EXIT_FAILURE);
meillo@10 122 }
meillo@10 123 logwrite(LOG_NOTICE, "listening on interface %s:%d\n", iface->address, iface->port);
meillo@10 124 DEBUG(5) debugf("sock = %d\n", sock);
meillo@10 125 FD_SET(sock, &active_fd_set);
meillo@10 126 }
meillo@0 127
meillo@10 128 /* setup handler for HUP signal: */
meillo@10 129 signal(SIGHUP, sighup_handler);
meillo@10 130 signal(SIGCHLD, sigchld_handler);
meillo@0 131
meillo@15 132 /* now that we have our socket(s), we can give up root privileges */
meillo@10 133 if (!conf.run_as_user) {
meillo@10 134 if (setegid(conf.mail_gid) != 0) {
meillo@10 135 logwrite(LOG_ALERT, "could not change gid to %d: %s\n", conf.mail_gid, strerror(errno));
meillo@10 136 exit(EXIT_FAILURE);
meillo@10 137 }
meillo@10 138 if (seteuid(conf.mail_uid) != 0) {
meillo@10 139 logwrite(LOG_ALERT, "could not change uid to %d: %s\n", conf.mail_uid, strerror(errno));
meillo@10 140 exit(EXIT_FAILURE);
meillo@10 141 }
meillo@10 142 }
meillo@0 143
meillo@10 144 /* sel_ret = 0; */
meillo@10 145 time(&time_before);
meillo@10 146 time_before -= qival;
meillo@10 147 sel_ret = -1;
meillo@0 148
meillo@10 149 while (1) {
meillo@0 150
meillo@10 151 /* if we were interrupted by an incoming connection (or a signal)
meillo@10 152 we have to recalculate the time until the next queue run should
meillo@10 153 occur. select may put a value into tm, but doc for select() says
meillo@10 154 we should not use it. */
meillo@10 155 if (qival > 0) {
meillo@10 156 time(&time_now);
meillo@10 157 if (sel_ret == 0) { /* we are either just starting or did a queue run */
meillo@10 158 tm.tv_sec = qival;
meillo@10 159 tm.tv_usec = 0;
meillo@10 160 time_before = time_now;
meillo@10 161 } else {
meillo@10 162 tm.tv_sec = qival - (time_now - time_before);
meillo@10 163 tm.tv_usec = 0;
meillo@0 164
meillo@10 165 /* race condition, very unlikely (but possible): */
meillo@10 166 if (tm.tv_sec < 0)
meillo@10 167 tm.tv_sec = 0;
meillo@10 168 }
meillo@10 169 }
meillo@10 170 /* Block until input arrives on one or more active sockets,
meillo@15 171 or signal arrives, or queuing interval time elapsed (if qival > 0) */
meillo@10 172 read_fd_set = active_fd_set;
meillo@10 173 if ((sel_ret = select(FD_SETSIZE, &read_fd_set, NULL, NULL, qival > 0 ? &tm : NULL)) < 0) {
meillo@10 174 if (errno != EINTR) {
meillo@10 175 logwrite(LOG_ALERT, "select: (terminating): %s\n", strerror(errno));
meillo@10 176 exit(EXIT_FAILURE);
meillo@10 177 } else {
meillo@10 178 if (sighup_seen) {
meillo@10 179 logwrite(LOG_NOTICE, "HUP signal received. Restarting daemon\n");
meillo@0 180
meillo@10 181 for (i = 0; i < FD_SETSIZE; i++)
meillo@10 182 if (FD_ISSET(i, &active_fd_set))
meillo@10 183 close(i);
meillo@0 184
meillo@10 185 execv(argv[0], &(argv[0]));
meillo@10 186 logwrite(LOG_ALERT, "restarting failed: %s\n", strerror(errno));
meillo@10 187 exit(EXIT_FAILURE);
meillo@10 188 }
meillo@10 189 }
meillo@10 190 } else if (sel_ret > 0) {
meillo@10 191 for (i = 0; i < FD_SETSIZE; i++) {
meillo@10 192 if (FD_ISSET(i, &read_fd_set)) {
meillo@10 193 int sock = i;
meillo@10 194 int new;
meillo@10 195 size = sizeof(clientname);
meillo@10 196 new = accept(sock, (struct sockaddr *) &clientname, &size);
meillo@10 197 if (new < 0) {
meillo@10 198 logwrite(LOG_ALERT, "accept: (ignoring): %s\n", strerror(errno));
meillo@10 199 } else
meillo@10 200 accept_connect(sock, new, &clientname);
meillo@10 201 }
meillo@10 202 }
meillo@10 203 } else {
meillo@10 204 /* If select returns 0, the interval time has elapsed.
meillo@10 205 We start a new queue runner process */
meillo@10 206 int pid;
meillo@10 207 signal(SIGCHLD, sigchld_handler);
meillo@10 208 if ((pid = fork()) == 0) {
meillo@10 209 queue_run();
meillo@10 210
meillo@10 211 _exit(EXIT_SUCCESS);
meillo@10 212 } else if (pid < 0) {
meillo@10 213 logwrite(LOG_ALERT, "could not fork for queue run");
meillo@10 214 }
meillo@10 215 }
meillo@0 216 }
meillo@0 217 }