1 /* 2 * Copyright (c) 2008-2014, Simon Schubert <2@0x2c.org>. 3 * Copyright (c) 2008 The DragonFly Project. All rights reserved. 4 * 5 * This code is derived from software contributed to The DragonFly Project 6 * by Simon Schubert <2@0x2c.org>. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in 16 * the documentation and/or other materials provided with the 17 * distribution. 18 * 3. Neither the name of The DragonFly Project nor the names of its 19 * contributors may be used to endorse or promote products derived 20 * from this software without specific, prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 23 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 25 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 26 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 27 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 28 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 29 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 30 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 31 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 32 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/types.h> 37 #include <sys/wait.h> 38 39 #include <err.h> 40 #include <errno.h> 41 #include <fcntl.h> 42 #include <limits.h> 43 #include <paths.h> 44 #include <signal.h> 45 #include <stdint.h> 46 #include <stdio.h> 47 #include <strings.h> 48 #include <string.h> 49 #include <syslog.h> 50 #include <unistd.h> 51 52 #include "dma.h" 53 54 static int 55 create_mbox(const char *name) 56 { 57 struct sigaction sa, osa; 58 pid_t child, waitchild; 59 int status; 60 int i; 61 long maxfd; 62 int e; 63 int r = -1; 64 65 /* 66 * We need to enable SIGCHLD temporarily so that waitpid works. 67 */ 68 bzero(&sa, sizeof(sa)); 69 sa.sa_handler = SIG_DFL; 70 sigaction(SIGCHLD, &sa, &osa); 71 72 do_timeout(100, 0); 73 74 child = fork(); 75 switch (child) { 76 case 0: 77 /* child */ 78 maxfd = sysconf(_SC_OPEN_MAX); 79 if (maxfd == -1) 80 maxfd = 1024; /* what can we do... */ 81 82 for (i = 3; i <= maxfd; ++i) 83 close(i); 84 85 execl(LIBEXEC_PATH "/dma-mbox-create", "dma-mbox-create", name, NULL); 86 syslog(LOG_ERR, "cannot execute "LIBEXEC_PATH"/dma-mbox-create: %m"); 87 exit(EX_SOFTWARE); 88 89 default: 90 /* parent */ 91 waitchild = waitpid(child, &status, 0); 92 93 e = errno; 94 95 do_timeout(0, 0); 96 97 if (waitchild == -1 && e == EINTR) { 98 syslog(LOG_ERR, "hung child while creating mbox `%s': %m", name); 99 break; 100 } 101 102 if (waitchild == -1) { 103 syslog(LOG_ERR, "child disappeared while creating mbox `%s': %m", name); 104 break; 105 } 106 107 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { 108 syslog(LOG_ERR, "error creating mbox `%s'", name); 109 break; 110 } 111 112 /* success */ 113 r = 0; 114 break; 115 116 case -1: 117 /* error */ 118 syslog(LOG_ERR, "error creating mbox"); 119 break; 120 } 121 122 sigaction(SIGCHLD, &osa, NULL); 123 124 return (r); 125 } 126 127 int 128 deliver_local(struct qitem *it) 129 { 130 char fn[PATH_MAX+1]; 131 char line[1000]; 132 const char *sender; 133 const char *newline = "\n"; 134 size_t linelen; 135 int tries = 0; 136 int mbox; 137 int error; 138 int hadnl = 0; 139 off_t mboxlen; 140 time_t now = time(NULL); 141 142 error = snprintf(fn, sizeof(fn), "%s/%s", _PATH_MAILDIR, it->addr); 143 if (error < 0 || (size_t)error >= sizeof(fn)) { 144 syslog(LOG_NOTICE, "local delivery deferred: %m"); 145 return (1); 146 } 147 148 retry: 149 /* wait for a maximum of 100s to get the lock to the file */ 150 do_timeout(100, 0); 151 152 /* don't use O_CREAT here, because we might be running as the wrong user. */ 153 mbox = open_locked(fn, O_WRONLY|O_APPEND); 154 if (mbox < 0) { 155 int e = errno; 156 157 do_timeout(0, 0); 158 159 switch (e) { 160 case EACCES: 161 case ENOENT: 162 /* 163 * The file does not exist or we can't access it. 164 * Call dma-mbox-create to create it and fix permissions. 165 */ 166 if (tries > 0 || create_mbox(it->addr) != 0) { 167 syslog(LOG_ERR, "local delivery deferred: can not create `%s'", fn); 168 return (1); 169 } 170 ++tries; 171 goto retry; 172 173 case EINTR: 174 syslog(LOG_NOTICE, "local delivery deferred: can not lock `%s'", fn); 175 break; 176 177 default: 178 syslog(LOG_NOTICE, "local delivery deferred: can not open `%s': %m", fn); 179 break; 180 } 181 return (1); 182 } 183 do_timeout(0, 0); 184 185 mboxlen = lseek(mbox, 0, SEEK_END); 186 187 /* New mails start with \nFrom ...., unless we're at the beginning of the mbox */ 188 if (mboxlen == 0) 189 newline = ""; 190 191 /* If we're bouncing a message, claim it comes from MAILER-DAEMON */ 192 sender = it->sender; 193 if (strcmp(sender, "") == 0) 194 sender = "MAILER-DAEMON"; 195 196 if (fseek(it->mailf, 0, SEEK_SET) != 0) { 197 syslog(LOG_NOTICE, "local delivery deferred: can not seek: %m"); 198 goto out; 199 } 200 201 error = snprintf(line, sizeof(line), "%sFrom %s %s", newline, sender, ctime(&now)); 202 if (error < 0 || (size_t)error >= sizeof(line)) { 203 syslog(LOG_NOTICE, "local delivery deferred: can not write header: %m"); 204 goto out; 205 } 206 if (write(mbox, line, error) != error) 207 goto wrerror; 208 209 while (!feof(it->mailf)) { 210 if (fgets(line, sizeof(line), it->mailf) == NULL) 211 break; 212 linelen = strlen(line); 213 if (linelen == 0 || line[linelen - 1] != '\n') { 214 syslog(LOG_CRIT, "local delivery failed: corrupted queue file"); 215 snprintf(errmsg, sizeof(errmsg), "corrupted queue file"); 216 error = -1; 217 goto chop; 218 } 219 220 /* 221 * mboxro processing: 222 * - escape lines that start with "From " with a > sign. 223 * - be reversible by escaping lines that contain an arbitrary 224 * number of > signs, followed by "From ", i.e. />*From / in regexp. 225 * - strict mbox processing only requires escaping after empty lines, 226 * yet most MUAs seem to relax this requirement and will treat any 227 * line starting with "From " as the beginning of a new mail. 228 */ 229 if ((!MBOX_STRICT || hadnl) && 230 strncmp(&line[strspn(line, ">")], "From ", 5) == 0) { 231 const char *gt = ">"; 232 233 if (write(mbox, gt, 1) != 1) 234 goto wrerror; 235 hadnl = 0; 236 } else if (strcmp(line, "\n") == 0) { 237 hadnl = 1; 238 } else { 239 hadnl = 0; 240 } 241 if ((size_t)write(mbox, line, linelen) != linelen) 242 goto wrerror; 243 } 244 close(mbox); 245 return (0); 246 247 wrerror: 248 syslog(LOG_ERR, "local delivery failed: write error: %m"); 249 error = 1; 250 chop: 251 if (ftruncate(mbox, mboxlen) != 0) 252 syslog(LOG_WARNING, "error recovering mbox `%s': %m", fn); 253 out: 254 close(mbox); 255 return (error); 256 } 257