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 <syslog.h> 48 #include <unistd.h> 49 50 #include "dma.h" 51 52 static int 53 create_mbox(const char *name) 54 { 55 struct sigaction sa, osa; 56 pid_t child, waitchild; 57 int status; 58 int i; 59 long maxfd; 60 int e; 61 int r = -1; 62 63 /* 64 * We need to enable SIGCHLD temporarily so that waitpid works. 65 */ 66 bzero(&sa, sizeof(sa)); 67 sa.sa_handler = SIG_DFL; 68 sigaction(SIGCHLD, &sa, &osa); 69 70 do_timeout(100, 0); 71 72 child = fork(); 73 switch (child) { 74 case 0: 75 /* child */ 76 maxfd = sysconf(_SC_OPEN_MAX); 77 if (maxfd == -1) 78 maxfd = 1024; /* what can we do... */ 79 80 for (i = 3; i <= maxfd; ++i) 81 close(i); 82 83 execl(LIBEXEC_PATH "/dma-mbox-create", "dma-mbox-create", name, NULL); 84 syslog(LOG_ERR, "cannot execute "LIBEXEC_PATH"/dma-mbox-create: %m"); 85 exit(1); 86 87 default: 88 /* parent */ 89 waitchild = waitpid(child, &status, 0); 90 91 e = errno; 92 93 do_timeout(0, 0); 94 95 if (waitchild == -1 && e == EINTR) { 96 syslog(LOG_ERR, "hung child while creating mbox `%s': %m", name); 97 break; 98 } 99 100 if (waitchild == -1) { 101 syslog(LOG_ERR, "child disappeared while creating mbox `%s': %m", name); 102 break; 103 } 104 105 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { 106 syslog(LOG_ERR, "error creating mbox `%s'", name); 107 break; 108 } 109 110 /* success */ 111 r = 0; 112 break; 113 114 case -1: 115 /* error */ 116 syslog(LOG_ERR, "error creating mbox"); 117 break; 118 } 119 120 sigaction(SIGCHLD, &osa, NULL); 121 122 return (r); 123 } 124 125 int 126 deliver_local(struct qitem *it) 127 { 128 char fn[PATH_MAX+1]; 129 char line[1000]; 130 const char *sender; 131 const char *newline = "\n"; 132 size_t linelen; 133 int tries = 0; 134 int mbox; 135 int error; 136 int hadnl = 0; 137 off_t mboxlen; 138 time_t now = time(NULL); 139 140 error = snprintf(fn, sizeof(fn), "%s/%s", _PATH_MAILDIR, it->addr); 141 if (error < 0 || (size_t)error >= sizeof(fn)) { 142 syslog(LOG_NOTICE, "local delivery deferred: %m"); 143 return (1); 144 } 145 146 retry: 147 /* wait for a maximum of 100s to get the lock to the file */ 148 do_timeout(100, 0); 149 150 /* don't use O_CREAT here, because we might be running as the wrong user. */ 151 mbox = open_locked(fn, O_WRONLY|O_APPEND); 152 if (mbox < 0) { 153 int e = errno; 154 155 do_timeout(0, 0); 156 157 switch (e) { 158 case EACCES: 159 case ENOENT: 160 /* 161 * The file does not exist or we can't access it. 162 * Call dma-mbox-create to create it and fix permissions. 163 */ 164 if (tries > 0 || create_mbox(it->addr) != 0) { 165 syslog(LOG_ERR, "local delivery deferred: can not create `%s'", fn); 166 return (1); 167 } 168 ++tries; 169 goto retry; 170 171 case EINTR: 172 syslog(LOG_NOTICE, "local delivery deferred: can not lock `%s'", fn); 173 break; 174 175 default: 176 syslog(LOG_NOTICE, "local delivery deferred: can not open `%s': %m", fn); 177 break; 178 } 179 return (1); 180 } 181 do_timeout(0, 0); 182 183 mboxlen = lseek(mbox, 0, SEEK_END); 184 185 /* New mails start with \nFrom ...., unless we're at the beginning of the mbox */ 186 if (mboxlen == 0) 187 newline = ""; 188 189 /* If we're bouncing a message, claim it comes from MAILER-DAEMON */ 190 sender = it->sender; 191 if (strcmp(sender, "") == 0) 192 sender = "MAILER-DAEMON"; 193 194 if (fseek(it->mailf, 0, SEEK_SET) != 0) { 195 syslog(LOG_NOTICE, "local delivery deferred: can not seek: %m"); 196 goto out; 197 } 198 199 error = snprintf(line, sizeof(line), "%sFrom %s\t%s", newline, sender, ctime(&now)); 200 if (error < 0 || (size_t)error >= sizeof(line)) { 201 syslog(LOG_NOTICE, "local delivery deferred: can not write header: %m"); 202 goto out; 203 } 204 if (write(mbox, line, error) != error) 205 goto wrerror; 206 207 while (!feof(it->mailf)) { 208 if (fgets(line, sizeof(line), it->mailf) == NULL) 209 break; 210 linelen = strlen(line); 211 if (linelen == 0 || line[linelen - 1] != '\n') { 212 syslog(LOG_CRIT, "local delivery failed: corrupted queue file"); 213 snprintf(errmsg, sizeof(errmsg), "corrupted queue file"); 214 error = -1; 215 goto chop; 216 } 217 218 /* 219 * mboxro processing: 220 * - escape lines that start with "From " with a > sign. 221 * - be reversable by escaping lines that contain an arbitrary 222 * number of > signs, followed by "From ", i.e. />*From / in regexp. 223 * - strict mbox processing only requires escaping after empty lines, 224 * yet most MUAs seem to relax this requirement and will treat any 225 * line starting with "From " as the beginning of a new mail. 226 */ 227 if ((!MBOX_STRICT || hadnl) && 228 strncmp(&line[strspn(line, ">")], "From ", 5) == 0) { 229 const char *gt = ">"; 230 231 if (write(mbox, gt, 1) != 1) 232 goto wrerror; 233 hadnl = 0; 234 } else if (strcmp(line, "\n") == 0) { 235 hadnl = 1; 236 } else { 237 hadnl = 0; 238 } 239 if ((size_t)write(mbox, line, linelen) != linelen) 240 goto wrerror; 241 } 242 close(mbox); 243 return (0); 244 245 wrerror: 246 syslog(LOG_ERR, "local delivery failed: write error: %m"); 247 error = 1; 248 chop: 249 if (ftruncate(mbox, mboxlen) != 0) 250 syslog(LOG_WARNING, "error recovering mbox `%s': %m", fn); 251 out: 252 close(mbox); 253 return (error); 254 } 255