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 <string.h> 48 #include <syslog.h> 49 #include <unistd.h> 50 51 #include "dma.h" 52 53 static int 54 create_mbox(const char *name) 55 { 56 struct sigaction sa, osa; 57 pid_t child, waitchild; 58 int status; 59 int i; 60 long maxfd; 61 int e; 62 int r = -1; 63 64 /* 65 * We need to enable SIGCHLD temporarily so that waitpid works. 66 */ 67 bzero(&sa, sizeof(sa)); 68 sa.sa_handler = SIG_DFL; 69 sigaction(SIGCHLD, &sa, &osa); 70 71 do_timeout(100, 0); 72 73 child = fork(); 74 switch (child) { 75 case 0: 76 /* child */ 77 maxfd = sysconf(_SC_OPEN_MAX); 78 if (maxfd == -1) 79 maxfd = 1024; /* what can we do... */ 80 81 for (i = 3; i <= maxfd; ++i) 82 close(i); 83 84 execl(LIBEXEC_PATH "/dma-mbox-create", "dma-mbox-create", name, NULL); 85 syslog(LOG_ERR, "cannot execute "LIBEXEC_PATH"/dma-mbox-create: %m"); 86 exit(EX_SOFTWARE); 87 88 default: 89 /* parent */ 90 waitchild = waitpid(child, &status, 0); 91 92 e = errno; 93 94 do_timeout(0, 0); 95 96 if (waitchild == -1 && e == EINTR) { 97 syslog(LOG_ERR, "hung child while creating mbox `%s': %m", name); 98 break; 99 } 100 101 if (waitchild == -1) { 102 syslog(LOG_ERR, "child disappeared while creating mbox `%s': %m", name); 103 break; 104 } 105 106 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { 107 syslog(LOG_ERR, "error creating mbox `%s'", name); 108 break; 109 } 110 111 /* success */ 112 r = 0; 113 break; 114 115 case -1: 116 /* error */ 117 syslog(LOG_ERR, "error creating mbox"); 118 break; 119 } 120 121 sigaction(SIGCHLD, &osa, NULL); 122 123 return (r); 124 } 125 126 int 127 deliver_local(struct qitem *it) 128 { 129 char fn[PATH_MAX+1]; 130 char line[1000]; 131 const char *sender; 132 const char *newline = "\n"; 133 size_t linelen; 134 int tries = 0; 135 int mbox; 136 int error; 137 int hadnl = 0; 138 off_t mboxlen; 139 time_t now = time(NULL); 140 141 error = snprintf(fn, sizeof(fn), "%s/%s", _PATH_MAILDIR, it->addr); 142 if (error < 0 || (size_t)error >= sizeof(fn)) { 143 syslog(LOG_NOTICE, "local delivery deferred: %m"); 144 return (1); 145 } 146 147 retry: 148 /* wait for a maximum of 100s to get the lock to the file */ 149 do_timeout(100, 0); 150 151 /* don't use O_CREAT here, because we might be running as the wrong user. */ 152 mbox = open_locked(fn, O_WRONLY|O_APPEND); 153 if (mbox < 0) { 154 int e = errno; 155 156 do_timeout(0, 0); 157 158 switch (e) { 159 case EACCES: 160 case ENOENT: 161 /* 162 * The file does not exist or we can't access it. 163 * Call dma-mbox-create to create it and fix permissions. 164 */ 165 if (tries > 0 || create_mbox(it->addr) != 0) { 166 syslog(LOG_ERR, "local delivery deferred: can not create `%s'", fn); 167 return (1); 168 } 169 ++tries; 170 goto retry; 171 172 case EINTR: 173 syslog(LOG_NOTICE, "local delivery deferred: can not lock `%s'", fn); 174 break; 175 176 default: 177 syslog(LOG_NOTICE, "local delivery deferred: can not open `%s': %m", fn); 178 break; 179 } 180 return (1); 181 } 182 do_timeout(0, 0); 183 184 mboxlen = lseek(mbox, 0, SEEK_END); 185 186 /* New mails start with \nFrom ...., unless we're at the beginning of the mbox */ 187 if (mboxlen == 0) 188 newline = ""; 189 190 /* If we're bouncing a message, claim it comes from MAILER-DAEMON */ 191 sender = it->sender; 192 if (strcmp(sender, "") == 0) 193 sender = "MAILER-DAEMON"; 194 195 if (fseek(it->mailf, 0, SEEK_SET) != 0) { 196 syslog(LOG_NOTICE, "local delivery deferred: can not seek: %m"); 197 goto out; 198 } 199 200 error = snprintf(line, sizeof(line), "%sFrom %s %s", newline, sender, ctime(&now)); 201 if (error < 0 || (size_t)error >= sizeof(line)) { 202 syslog(LOG_NOTICE, "local delivery deferred: can not write header: %m"); 203 goto out; 204 } 205 if (write(mbox, line, error) != error) 206 goto wrerror; 207 208 while (!feof(it->mailf)) { 209 if (fgets(line, sizeof(line), it->mailf) == NULL) 210 break; 211 linelen = strlen(line); 212 if (linelen == 0 || line[linelen - 1] != '\n') { 213 syslog(LOG_CRIT, "local delivery failed: corrupted queue file"); 214 snprintf(errmsg, sizeof(errmsg), "corrupted queue file"); 215 error = -1; 216 goto chop; 217 } 218 219 /* 220 * mboxro processing: 221 * - escape lines that start with "From " with a > sign. 222 * - be reversable by escaping lines that contain an arbitrary 223 * number of > signs, followed by "From ", i.e. />*From / in regexp. 224 * - strict mbox processing only requires escaping after empty lines, 225 * yet most MUAs seem to relax this requirement and will treat any 226 * line starting with "From " as the beginning of a new mail. 227 */ 228 if ((!MBOX_STRICT || hadnl) && 229 strncmp(&line[strspn(line, ">")], "From ", 5) == 0) { 230 const char *gt = ">"; 231 232 if (write(mbox, gt, 1) != 1) 233 goto wrerror; 234 hadnl = 0; 235 } else if (strcmp(line, "\n") == 0) { 236 hadnl = 1; 237 } else { 238 hadnl = 0; 239 } 240 if ((size_t)write(mbox, line, linelen) != linelen) 241 goto wrerror; 242 } 243 close(mbox); 244 return (0); 245 246 wrerror: 247 syslog(LOG_ERR, "local delivery failed: write error: %m"); 248 error = 1; 249 chop: 250 if (ftruncate(mbox, mboxlen) != 0) 251 syslog(LOG_WARNING, "error recovering mbox `%s': %m", fn); 252 out: 253 close(mbox); 254 return (error); 255 } 256