diff options
Diffstat (limited to 'local.c')
| -rw-r--r-- | local.c | 253 |
1 files changed, 253 insertions, 0 deletions
diff --git a/local.c b/local.c new file mode 100644 index 0000000000000..6a6407ef86527 --- /dev/null +++ b/local.c @@ -0,0 +1,253 @@ +/* + * Copyright (c) 2008 The DragonFly Project. All rights reserved. + * + * This code is derived from software contributed to The DragonFly Project + * by Simon 'corecode' Schubert <corecode@fs.ei.tum.de>. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name of The DragonFly Project nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific, prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/types.h> +#include <sys/wait.h> + +#include <err.h> +#include <errno.h> +#include <fcntl.h> +#include <limits.h> +#include <paths.h> +#include <signal.h> +#include <stdint.h> +#include <stdio.h> +#include <syslog.h> +#include <unistd.h> + +#include "dma.h" + +static int +create_mbox(const char *name) +{ + struct sigaction sa, osa; + pid_t child, waitchild; + int status; + int i; + long maxfd; + int e; + int r = -1; + + /* + * We need to enable SIGCHLD temporarily so that waitpid works. + */ + bzero(&sa, sizeof(sa)); + sa.sa_handler = SIG_DFL; + sigaction(SIGCHLD, &sa, &osa); + + do_timeout(100, 0); + + child = fork(); + switch (child) { + case 0: + /* child */ + maxfd = sysconf(_SC_OPEN_MAX); + if (maxfd == -1) + maxfd = 1024; /* what can we do... */ + + for (i = 3; i <= maxfd; ++i) + close(i); + + execl(LIBEXEC_PATH "/dma-mbox-create", "dma-mbox-create", name, NULL); + syslog(LOG_ERR, "cannot execute "LIBEXEC_PATH"/dma-mbox-create: %m"); + exit(1); + + default: + /* parent */ + waitchild = waitpid(child, &status, 0); + + e = errno; + + do_timeout(0, 0); + + if (waitchild == -1 && e == EINTR) { + syslog(LOG_ERR, "hung child while creating mbox `%s': %m", name); + break; + } + + if (waitchild == -1) { + syslog(LOG_ERR, "child disappeared while creating mbox `%s': %m", name); + break; + } + + if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { + syslog(LOG_ERR, "error creating mbox `%s'", name); + break; + } + + /* success */ + r = 0; + break; + + case -1: + /* error */ + syslog(LOG_ERR, "error creating mbox"); + break; + } + + sigaction(SIGCHLD, &osa, NULL); + + return (r); +} + +int +deliver_local(struct qitem *it) +{ + char fn[PATH_MAX+1]; + char line[1000]; + const char *sender; + const char *newline = "\n"; + size_t linelen; + int tries = 0; + int mbox; + int error; + int hadnl = 0; + off_t mboxlen; + time_t now = time(NULL); + + error = snprintf(fn, sizeof(fn), "%s/%s", _PATH_MAILDIR, it->addr); + if (error < 0 || (size_t)error >= sizeof(fn)) { + syslog(LOG_NOTICE, "local delivery deferred: %m"); + return (1); + } + +retry: + /* wait for a maximum of 100s to get the lock to the file */ + do_timeout(100, 0); + + /* don't use O_CREAT here, because we might be running as the wrong user. */ + mbox = open_locked(fn, O_WRONLY|O_APPEND); + if (mbox < 0) { + int e = errno; + + do_timeout(0, 0); + + switch (e) { + case EACCES: + case ENOENT: + /* + * The file does not exist or we can't access it. + * Call dma-mbox-create to create it and fix permissions. + */ + if (tries > 0 || create_mbox(it->addr) != 0) { + syslog(LOG_ERR, "local delivery deferred: can not create `%s'", fn); + return (1); + } + ++tries; + goto retry; + + case EINTR: + syslog(LOG_NOTICE, "local delivery deferred: can not lock `%s'", fn); + break; + + default: + syslog(LOG_NOTICE, "local delivery deferred: can not open `%s': %m", fn); + break; + } + return (1); + } + do_timeout(0, 0); + + mboxlen = lseek(mbox, 0, SEEK_END); + + /* New mails start with \nFrom ...., unless we're at the beginning of the mbox */ + if (mboxlen == 0) + newline = ""; + + /* If we're bouncing a message, claim it comes from MAILER-DAEMON */ + sender = it->sender; + if (strcmp(sender, "") == 0) + sender = "MAILER-DAEMON"; + + if (fseek(it->mailf, 0, SEEK_SET) != 0) { + syslog(LOG_NOTICE, "local delivery deferred: can not seek: %m"); + goto out; + } + + error = snprintf(line, sizeof(line), "%sFrom %s\t%s", newline, sender, ctime(&now)); + if (error < 0 || (size_t)error >= sizeof(line)) { + syslog(LOG_NOTICE, "local delivery deferred: can not write header: %m"); + goto out; + } + if (write(mbox, line, error) != error) + goto wrerror; + + while (!feof(it->mailf)) { + if (fgets(line, sizeof(line), it->mailf) == NULL) + break; + linelen = strlen(line); + if (linelen == 0 || line[linelen - 1] != '\n') { + syslog(LOG_CRIT, "local delivery failed: corrupted queue file"); + snprintf(errmsg, sizeof(errmsg), "corrupted queue file"); + error = -1; + goto chop; + } + + /* + * mboxro processing: + * - escape lines that start with "From " with a > sign. + * - be reversable by escaping lines that contain an arbitrary + * number of > signs, followed by "From ", i.e. />*From / in regexp. + * - strict mbox processing only requires escaping after empty lines, + * yet most MUAs seem to relax this requirement and will treat any + * line starting with "From " as the beginning of a new mail. + */ + if ((!MBOX_STRICT || hadnl) && + strncmp(&line[strspn(line, ">")], "From ", 5) == 0) { + const char *gt = ">"; + + if (write(mbox, gt, 1) != 1) + goto wrerror; + hadnl = 0; + } else if (strcmp(line, "\n") == 0) { + hadnl = 1; + } else { + hadnl = 0; + } + if ((size_t)write(mbox, line, linelen) != linelen) + goto wrerror; + } + close(mbox); + return (0); + +wrerror: + syslog(LOG_ERR, "local delivery failed: write error: %m"); + error = 1; +chop: + if (ftruncate(mbox, mboxlen) != 0) + syslog(LOG_WARNING, "error recovering mbox `%s': %m", fn); +out: + close(mbox); + return (error); +} |