| 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 | } |