1 /* 2 * Copyright (c) 2008 The DragonFly Project. All rights reserved. 3 * 4 * This code is derived from software contributed to The DragonFly Project 5 * by Simon 'corecode' Schubert <corecode@fs.ei.tum.de>. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * 3. Neither the name of The DragonFly Project nor the names of its 18 * contributors may be used to endorse or promote products derived 19 * from this software without specific, prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #include <sys/types.h> 36 #include <sys/wait.h> 37 38 #include <err.h> 39 #include <errno.h> 40 #include <fcntl.h> 41 #include <limits.h> 42 #include <paths.h> 43 #include <signal.h> 44 #include <stdint.h> 45 #include <stdio.h> 46 #include <syslog.h> 47 #include <unistd.h> 48 49 #include "dma.h" 50 51 static int 52 create_mbox(const char *name) 53 { 54 struct sigaction sa, osa; 55 pid_t child, waitchild; 56 int status; 57 int i; 58 long maxfd; 59 int e; 60 int r = -1; 61 62 /* 63 * We need to enable SIGCHLD temporarily so that waitpid works. 64 */ 65 bzero(&sa, sizeof(sa)); 66 sa.sa_handler = SIG_DFL; 67 sigaction(SIGCHLD, &sa, &osa); 68 69 do_timeout(100, 0); 70 71 child = fork(); 72 switch (child) { 73 case 0: 74 /* child */ 75 maxfd = sysconf(_SC_OPEN_MAX); 76 if (maxfd == -1) 77 maxfd = 1024; /* what can we do... */ 78 79 for (i = 3; i <= maxfd; ++i) 80 close(i); 81 82 execl(LIBEXEC_PATH "/dma-mbox-create", "dma-mbox-create", name, NULL); 83 syslog(LOG_ERR, "cannot execute "LIBEXEC_PATH"/dma-mbox-create: %m"); 84 exit(1); 85 86 default: 87 /* parent */ 88 waitchild = waitpid(child, &status, 0); 89 90 e = errno; 91 92 do_timeout(0, 0); 93 94 if (waitchild == -1 && e == EINTR) { 95 syslog(LOG_ERR, "hung child while creating mbox `%s': %m", name); 96 break; 97 } 98 99 if (waitchild == -1) { 100 syslog(LOG_ERR, "child disappeared while creating mbox `%s': %m", name); 101 break; 102 } 103 104 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { 105 syslog(LOG_ERR, "error creating mbox `%s'", name); 106 break; 107 } 108 109 /* success */ 110 r = 0; 111 break; 112 113 case -1: 114 /* error */ 115 syslog(LOG_ERR, "error creating mbox"); 116 break; 117 } 118 119 sigaction(SIGCHLD, &osa, NULL); 120 121 return (r); 122 } 123 124 int 125 deliver_local(struct qitem *it) 126 { 127 char fn[PATH_MAX+1]; 128 char line[1000]; 129 const char *sender; 130 const char *newline = "\n"; 131 size_t linelen; 132 int tries = 0; 133 int mbox; 134 int error; 135 int hadnl = 0; 136 off_t mboxlen; 137 time_t now = time(NULL); 138 139 error = snprintf(fn, sizeof(fn), "%s/%s", _PATH_MAILDIR, it->addr); 140 if (error < 0 || (size_t)error >= sizeof(fn)) { 141 syslog(LOG_NOTICE, "local delivery deferred: %m"); 142 return (1); 143 } 144 145 retry: 146 /* wait for a maximum of 100s to get the lock to the file */ 147 do_timeout(100, 0); 148 149 /* don't use O_CREAT here, because we might be running as the wrong user. */ 150 mbox = open_locked(fn, O_WRONLY|O_APPEND); 151 if (mbox < 0) { 152 int e = errno; 153 154 do_timeout(0, 0); 155 156 switch (e) { 157 case EACCES: 158 case ENOENT: 159 /* 160 * The file does not exist or we can't access it. 161 * Call dma-mbox-create to create it and fix permissions. 162 */ 163 if (tries > 0 || create_mbox(it->addr) != 0) { 164 syslog(LOG_ERR, "local delivery deferred: can not create `%s'", fn); 165 return (1); 166 } 167 ++tries; 168 goto retry; 169 170 case EINTR: 171 syslog(LOG_NOTICE, "local delivery deferred: can not lock `%s'", fn); 172 break; 173 174 default: 175 syslog(LOG_NOTICE, "local delivery deferred: can not open `%s': %m", fn); 176 break; 177 } 178 return (1); 179 } 180 do_timeout(0, 0); 181 182 mboxlen = lseek(mbox, 0, SEEK_END); 183 184 /* New mails start with \nFrom ...., unless we're at the beginning of the mbox */ 185 if (mboxlen == 0) 186 newline = ""; 187 188 /* If we're bouncing a message, claim it comes from MAILER-DAEMON */ 189 sender = it->sender; 190 if (strcmp(sender, "") == 0) 191 sender = "MAILER-DAEMON"; 192 193 if (fseek(it->mailf, 0, SEEK_SET) != 0) { 194 syslog(LOG_NOTICE, "local delivery deferred: can not seek: %m"); 195 goto out; 196 } 197 198 error = snprintf(line, sizeof(line), "%sFrom %s\t%s", newline, sender, ctime(&now)); 199 if (error < 0 || (size_t)error >= sizeof(line)) { 200 syslog(LOG_NOTICE, "local delivery deferred: can not write header: %m"); 201 goto out; 202 } 203 if (write(mbox, line, error) != error) 204 goto wrerror; 205 206 while (!feof(it->mailf)) { 207 if (fgets(line, sizeof(line), it->mailf) == NULL) 208 break; 209 linelen = strlen(line); 210 if (linelen == 0 || line[linelen - 1] != '\n') { 211 syslog(LOG_CRIT, "local delivery failed: corrupted queue file"); 212 snprintf(errmsg, sizeof(errmsg), "corrupted queue file"); 213 error = -1; 214 goto chop; 215 } 216 217 /* 218 * mboxro processing: 219 * - escape lines that start with "From " with a > sign. 220 * - be reversable by escaping lines that contain an arbitrary 221 * number of > signs, followed by "From ", i.e. />*From / in regexp. 222 * - strict mbox processing only requires escaping after empty lines, 223 * yet most MUAs seem to relax this requirement and will treat any 224 * line starting with "From " as the beginning of a new mail. 225 */ 226 if ((!MBOX_STRICT || hadnl) && 227 strncmp(&line[strspn(line, ">")], "From ", 5) == 0) { 228 const char *gt = ">"; 229 230 if (write(mbox, gt, 1) != 1) 231 goto wrerror; 232 hadnl = 0; 233 } else if (strcmp(line, "\n") == 0) { 234 hadnl = 1; 235 } else { 236 hadnl = 0; 237 } 238 if ((size_t)write(mbox, line, linelen) != linelen) 239 goto wrerror; 240 } 241 close(mbox); 242 return (0); 243 244 wrerror: 245 syslog(LOG_ERR, "local delivery failed: write error: %m"); 246 error = 1; 247 chop: 248 if (ftruncate(mbox, mboxlen) != 0) 249 syslog(LOG_WARNING, "error recovering mbox `%s': %m", fn); 250 out: 251 close(mbox); 252 return (error); 253 } 254