| Current File : //root/postfix-3.2.0/src/pickup/pickup.c |
/*++
/* NAME
/* pickup 8
/* SUMMARY
/* Postfix local mail pickup
/* SYNOPSIS
/* \fBpickup\fR [generic Postfix daemon options]
/* DESCRIPTION
/* The \fBpickup\fR(8) daemon waits for hints that new mail has been
/* dropped into the \fBmaildrop\fR directory, and feeds it into the
/* \fBcleanup\fR(8) daemon.
/* Ill-formatted files are deleted without notifying the originator.
/* This program expects to be run from the \fBmaster\fR(8) process
/* manager.
/* STANDARDS
/* .ad
/* .fi
/* None. The \fBpickup\fR(8) daemon does not interact with
/* the outside world.
/* SECURITY
/* .ad
/* .fi
/* The \fBpickup\fR(8) daemon is moderately security sensitive. It runs
/* with fixed low privilege and can run in a chrooted environment.
/* However, the program reads files from potentially hostile users.
/* The \fBpickup\fR(8) daemon opens no files for writing, is careful about
/* what files it opens for reading, and does not actually touch any data
/* that is sent to its public service endpoint.
/* DIAGNOSTICS
/* Problems and transactions are logged to \fBsyslogd\fR(8).
/* BUGS
/* The \fBpickup\fR(8) daemon copies mail from file to the \fBcleanup\fR(8)
/* daemon. It could avoid message copying overhead by sending a file
/* descriptor instead of file data, but then the already complex
/* \fBcleanup\fR(8) daemon would have to deal with unfiltered user data.
/* CONFIGURATION PARAMETERS
/* .ad
/* .fi
/* As the \fBpickup\fR(8) daemon is a relatively long-running process, up
/* to an hour may pass before a \fBmain.cf\fR change takes effect.
/* Use the command "\fBpostfix reload\fR" command to speed up a change.
/*
/* The text below provides only a parameter summary. See
/* \fBpostconf\fR(5) for more details including examples.
/* CONTENT INSPECTION CONTROLS
/* .ad
/* .fi
/* .IP "\fBcontent_filter (empty)\fR"
/* After the message is queued, send the entire message to the
/* specified \fItransport:destination\fR.
/* .IP "\fBreceive_override_options (empty)\fR"
/* Enable or disable recipient validation, built-in content
/* filtering, or address mapping.
/* MISCELLANEOUS CONTROLS
/* .ad
/* .fi
/* .IP "\fBconfig_directory (see 'postconf -d' output)\fR"
/* The default location of the Postfix main.cf and master.cf
/* configuration files.
/* .IP "\fBipc_timeout (3600s)\fR"
/* The time limit for sending or receiving information over an internal
/* communication channel.
/* .IP "\fBline_length_limit (2048)\fR"
/* Upon input, long lines are chopped up into pieces of at most
/* this length; upon delivery, long lines are reconstructed.
/* .IP "\fBmax_idle (100s)\fR"
/* The maximum amount of time that an idle Postfix daemon process waits
/* for an incoming connection before terminating voluntarily.
/* .IP "\fBmax_use (100)\fR"
/* The maximal number of incoming connections that a Postfix daemon
/* process will service before terminating voluntarily.
/* .IP "\fBprocess_id (read-only)\fR"
/* The process ID of a Postfix command or daemon process.
/* .IP "\fBprocess_name (read-only)\fR"
/* The process name of a Postfix command or daemon process.
/* .IP "\fBqueue_directory (see 'postconf -d' output)\fR"
/* The location of the Postfix top-level queue directory.
/* .IP "\fBsyslog_facility (mail)\fR"
/* The syslog facility of Postfix logging.
/* .IP "\fBsyslog_name (see 'postconf -d' output)\fR"
/* A prefix that is prepended to the process name in syslog
/* records, so that, for example, "smtpd" becomes "prefix/smtpd".
/* SEE ALSO
/* cleanup(8), message canonicalization
/* sendmail(1), Sendmail-compatible interface
/* postdrop(1), mail posting agent
/* postconf(5), configuration parameters
/* master(5), generic daemon options
/* master(8), process manager
/* syslogd(8), system logging
/* LICENSE
/* .ad
/* .fi
/* The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/* Wietse Venema
/* IBM T.J. Watson Research
/* P.O. Box 704
/* Yorktown Heights, NY 10598, USA
/*
/* Wietse Venema
/* Google, Inc.
/* 111 8th Avenue
/* New York, NY 10011, USA
/*--*/
/* System library. */
#include <sys_defs.h>
#include <sys/stat.h>
#include <dirent.h>
#include <unistd.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#include <ctype.h>
/* Utility library. */
#include <msg.h>
#include <scan_dir.h>
#include <vstring.h>
#include <vstream.h>
#include <set_ugid.h>
#include <safe_open.h>
#include <watchdog.h>
#include <stringops.h>
/* Global library. */
#include <mail_queue.h>
#include <mail_open_ok.h>
#include <mymalloc.h>
#include <mail_proto.h>
#include <cleanup_user.h>
#include <mail_date.h>
#include <mail_params.h>
#include <mail_conf.h>
#include <record.h>
#include <rec_type.h>
#include <lex_822.h>
#include <input_transp.h>
#include <rec_attr_map.h>
#include <mail_version.h>
#include <smtputf8.h>
/* Single-threaded server skeleton. */
#include <mail_server.h>
/* Application-specific. */
char *var_filter_xport;
char *var_input_transp;
/*
* Structure to bundle a bunch of information about a queue file.
*/
typedef struct {
char *id; /* queue file basename */
struct stat st; /* queue file status */
char *path; /* name for open/remove */
char *sender; /* sender address */
} PICKUP_INFO;
/*
* What action should be taken after attempting to deliver a message: remove
* the file from the maildrop, or leave it alone. The latter is also used
* for files that are still being written to.
*/
#define REMOVE_MESSAGE_FILE 1
#define KEEP_MESSAGE_FILE 2
/*
* Transparency: before mail is queued, do we allow address mapping,
* automatic bcc, header/body checks?
*/
int pickup_input_transp_mask;
/* file_read_error - handle error while reading queue file */
static int file_read_error(PICKUP_INFO *info, int type)
{
msg_warn("uid=%ld: unexpected or malformed record type %d",
(long) info->st.st_uid, type);
return (REMOVE_MESSAGE_FILE);
}
/* cleanup_service_error_reason - handle error writing to cleanup service. */
static int cleanup_service_error_reason(PICKUP_INFO *info, int status,
const char *reason)
{
/*
* XXX If the cleanup server gave a reason, then it was already logged.
* Don't bother logging it another time.
*
* XXX Discard a message without recipient. This can happen with "postsuper
* -r" when a message is already delivered (or bounced). The Postfix
* sendmail command rejects submissions without recipients.
*/
if (reason == 0 || *reason == 0)
msg_warn("%s: error writing %s: %s",
info->path, info->id, cleanup_strerror(status));
return ((status & (CLEANUP_STAT_BAD | CLEANUP_STAT_RCPT)) ?
REMOVE_MESSAGE_FILE : KEEP_MESSAGE_FILE);
}
#define cleanup_service_error(info, status) \
cleanup_service_error_reason((info), (status), (char *) 0)
/* copy_segment - copy a record group */
static int copy_segment(VSTREAM *qfile, VSTREAM *cleanup, PICKUP_INFO *info,
VSTRING *buf, char *expected)
{
int type;
int check_first = (*expected == REC_TYPE_CONTENT[0]);
int time_seen = 0;
char *attr_name;
char *attr_value;
char *saved_attr;
int skip_attr;
/*
* Limit the input record size. All front-end programs should protect the
* mail system against unreasonable inputs. This also requires that we
* limit the size of envelope records written by the local posting agent.
*
* Records with named attributes are filtered by postdrop(1).
*
* We must allow PTR records here because of "postsuper -r".
*/
for (;;) {
if ((type = rec_get(qfile, buf, var_line_limit)) < 0
|| strchr(expected, type) == 0)
return (file_read_error(info, type));
if (msg_verbose)
msg_info("%s: read %c %s", info->id, type, vstring_str(buf));
if (type == *expected)
break;
if (type == REC_TYPE_FROM) {
if (info->sender == 0)
info->sender = mystrdup(vstring_str(buf));
/* Compatibility with Postfix < 2.3. */
if (time_seen == 0)
rec_fprintf(cleanup, REC_TYPE_TIME, "%ld",
(long) info->st.st_mtime);
}
if (type == REC_TYPE_TIME)
time_seen = 1;
/*
* XXX Workaround: REC_TYPE_FILT (used in envelopes) == REC_TYPE_CONT
* (used in message content).
*
* As documented in postsuper(1), ignore content filter record.
*/
if (*expected != REC_TYPE_CONTENT[0]) {
if (type == REC_TYPE_FILT)
/* Discard FILTER record after "postsuper -r". */
continue;
if (type == REC_TYPE_RDR)
/* Discard REDIRECT record after "postsuper -r". */
continue;
}
if (*expected == REC_TYPE_EXTRACT[0]) {
if (type == REC_TYPE_RRTO)
/* Discard return-receipt record after "postsuper -r". */
continue;
if (type == REC_TYPE_ERTO)
/* Discard errors-to record after "postsuper -r". */
continue;
if (type == REC_TYPE_ATTR) {
saved_attr = mystrdup(vstring_str(buf));
skip_attr = (split_nameval(saved_attr,
&attr_name, &attr_value) == 0
&& rec_attr_map(attr_name) == 0);
myfree(saved_attr);
/* Discard other/header/body action after "postsuper -r". */
if (skip_attr)
continue;
}
}
/*
* XXX Force an empty record when the queue file content begins with
* whitespace, so that it won't be considered as being part of our
* own Received: header. What an ugly Kluge.
*/
if (check_first
&& (type == REC_TYPE_NORM || type == REC_TYPE_CONT)) {
check_first = 0;
if (VSTRING_LEN(buf) > 0 && IS_SPACE_TAB(vstring_str(buf)[0]))
rec_put(cleanup, REC_TYPE_NORM, "", 0);
}
if ((REC_PUT_BUF(cleanup, type, buf)) < 0)
return (cleanup_service_error(info, CLEANUP_STAT_WRITE));
}
return (0);
}
/* pickup_copy - copy message to cleanup service */
static int pickup_copy(VSTREAM *qfile, VSTREAM *cleanup,
PICKUP_INFO *info, VSTRING *buf)
{
time_t now = time((time_t *) 0);
int status;
char *name;
/*
* Protect against time-warped time stamps. Warn about mail that has been
* queued for an excessive amount of time. Allow for some time drift with
* network clients that mount the maildrop remotely - especially clients
* that can't get their daylight savings offsets right.
*/
#define DAY_SECONDS 86400
#define HOUR_SECONDS 3600
if (info->st.st_mtime > now + 2 * HOUR_SECONDS) {
msg_warn("%s: message dated %ld seconds into the future",
info->id, (long) (info->st.st_mtime - now));
info->st.st_mtime = now;
} else if (info->st.st_mtime < now - DAY_SECONDS) {
msg_warn("%s: message has been queued for %d days",
info->id, (int) ((now - info->st.st_mtime) / DAY_SECONDS));
}
/*
* Add content inspection transport. See also postsuper(1).
*/
if (*var_filter_xport)
rec_fprintf(cleanup, REC_TYPE_FILT, "%s", var_filter_xport);
/*
* Copy the message envelope segment. Allow only those records that we
* expect to see in the envelope section. The envelope segment must
* contain an envelope sender address.
*/
if ((status = copy_segment(qfile, cleanup, info, buf, REC_TYPE_ENVELOPE)) != 0)
return (status);
if (info->sender == 0) {
msg_warn("%s: uid=%ld: no envelope sender",
info->id, (long) info->st.st_uid);
return (REMOVE_MESSAGE_FILE);
}
/*
* For messages belonging to $mail_owner also log the maildrop queue id.
* This supports message tracking for mail requeued via "postsuper -r".
*/
#define MAIL_IS_REQUEUED(info) \
((info)->st.st_uid == var_owner_uid && ((info)->st.st_mode & S_IROTH) == 0)
if (MAIL_IS_REQUEUED(info)) {
msg_info("%s: uid=%d from=<%s> orig_id=%s", info->id,
(int) info->st.st_uid, info->sender,
((name = strrchr(info->path, '/')) != 0 ?
name + 1 : info->path));
} else {
msg_info("%s: uid=%d from=<%s>", info->id,
(int) info->st.st_uid, info->sender);
}
/*
* Message content segment. Send a dummy message length. Prepend a
* Received: header to the message contents. For tracing purposes,
* include the message file ownership, without revealing the login name.
*/
rec_fputs(cleanup, REC_TYPE_MESG, "");
rec_fprintf(cleanup, REC_TYPE_NORM, "Received: by %s (%s, from userid %ld)",
var_myhostname, var_mail_name, (long) info->st.st_uid);
rec_fprintf(cleanup, REC_TYPE_NORM, "\tid %s; %s", info->id,
mail_date(info->st.st_mtime));
/*
* Copy the message content segment. Allow only those records that we
* expect to see in the message content section.
*/
if ((status = copy_segment(qfile, cleanup, info, buf, REC_TYPE_CONTENT)) != 0)
return (status);
/*
* Send the segment with information extracted from message headers.
* Permit a non-empty extracted segment, so that list manager software
* can to output recipients after the message, and so that sysadmins can
* re-inject messages after a change of configuration.
*/
rec_fputs(cleanup, REC_TYPE_XTRA, "");
if ((status = copy_segment(qfile, cleanup, info, buf, REC_TYPE_EXTRACT)) != 0)
return (status);
/*
* There are no errors. Send the end-of-data marker, and get the cleanup
* service completion status. XXX Since the pickup service is unable to
* bounce, the cleanup service can report only soft errors here.
*/
rec_fputs(cleanup, REC_TYPE_END, "");
if (attr_scan(cleanup, ATTR_FLAG_MISSING,
RECV_ATTR_INT(MAIL_ATTR_STATUS, &status),
RECV_ATTR_STR(MAIL_ATTR_WHY, buf),
ATTR_TYPE_END) != 2)
return (cleanup_service_error(info, CLEANUP_STAT_WRITE));
/*
* Depending on the cleanup service completion status, delete the message
* file, or try again later. Bounces are dealt with by the cleanup
* service itself. The master process wakes up the cleanup service every
* now and then.
*/
if (status) {
return (cleanup_service_error_reason(info, status, vstring_str(buf)));
} else {
return (REMOVE_MESSAGE_FILE);
}
}
/* pickup_file - initialize for file copy and cleanup */
static int pickup_file(PICKUP_INFO *info)
{
VSTRING *buf = vstring_alloc(100);
int status;
VSTREAM *qfile;
VSTREAM *cleanup;
int cleanup_flags;
/*
* Open the submitted file. If we cannot open it, and we're not having a
* file descriptor leak problem, delete the submitted file, so that we
* won't keep complaining about the same file again and again. XXX
* Perhaps we should save "bad" files elsewhere for further inspection.
* XXX How can we delete a file when open() fails with ENOENT?
*/
qfile = safe_open(info->path, O_RDONLY | O_NONBLOCK, 0,
(struct stat *) 0, -1, -1, buf);
if (qfile == 0) {
if (errno != ENOENT)
msg_warn("open input file %s: %s", info->path, vstring_str(buf));
vstring_free(buf);
if (errno == EACCES)
msg_warn("if this file was created by Postfix < 1.1, then you may have to chmod a+r %s/%s",
var_queue_dir, info->path);
return (errno == EACCES ? KEEP_MESSAGE_FILE : REMOVE_MESSAGE_FILE);
}
/*
* Contact the cleanup service and read the queue ID that it has
* allocated. In case of trouble, request that the cleanup service
* bounces its copy of the message. because the original input file is
* not readable by the bounce service.
*
* If mail is re-injected with "postsuper -r", disable Milter applications.
* If they were run before the mail was queued then there is no need to
* run them again. Moreover, the queue file does not contain enough
* information to reproduce the exact same SMTP events and Sendmail
* macros that Milters received when the mail originally arrived in
* Postfix.
*
* The actual message copying code is in a separate routine, so that it is
* easier to implement the many possible error exits without forgetting
* to close files, or to release memory.
*/
cleanup_flags =
input_transp_cleanup(CLEANUP_FLAG_BOUNCE | CLEANUP_FLAG_MASK_EXTERNAL,
pickup_input_transp_mask);
/* As documented in postsuper(1). */
if (MAIL_IS_REQUEUED(info))
cleanup_flags &= ~CLEANUP_FLAG_MILTER;
else
cleanup_flags |= smtputf8_autodetect(MAIL_SRC_MASK_SENDMAIL);
cleanup = mail_connect_wait(MAIL_CLASS_PUBLIC, var_cleanup_service);
if (attr_scan(cleanup, ATTR_FLAG_STRICT,
RECV_ATTR_STR(MAIL_ATTR_QUEUEID, buf),
ATTR_TYPE_END) != 1
|| attr_print(cleanup, ATTR_FLAG_NONE,
SEND_ATTR_INT(MAIL_ATTR_FLAGS, cleanup_flags),
ATTR_TYPE_END) != 0) {
status = KEEP_MESSAGE_FILE;
} else {
info->id = mystrdup(vstring_str(buf));
status = pickup_copy(qfile, cleanup, info, buf);
}
vstream_fclose(qfile);
vstream_fclose(cleanup);
vstring_free(buf);
return (status);
}
/* pickup_init - init info structure */
static void pickup_init(PICKUP_INFO *info)
{
info->id = 0;
info->path = 0;
info->sender = 0;
}
/* pickup_free - wipe info structure */
static void pickup_free(PICKUP_INFO *info)
{
#define SAFE_FREE(x) { if (x) myfree(x); }
SAFE_FREE(info->id);
SAFE_FREE(info->path);
SAFE_FREE(info->sender);
}
/* pickup_service - service client */
static void pickup_service(char *unused_buf, ssize_t unused_len,
char *unused_service, char **argv)
{
SCAN_DIR *scan;
char *queue_name;
PICKUP_INFO info;
const char *path;
char *id;
int file_count;
/*
* Sanity check. This service takes no command-line arguments.
*/
if (argv[0])
msg_fatal("unexpected command-line argument: %s", argv[0]);
/*
* Skip over things that we don't want to open, such as files that are
* still being written, or garbage. Leave it up to the sysadmin to remove
* garbage. Keep scanning the queue directory until we stop removing
* files from it.
*
* When we find a file, stroke the watchdog so that it will not bark while
* some application is keeping us busy by injecting lots of mail into the
* maildrop directory.
*/
queue_name = MAIL_QUEUE_MAILDROP; /* XXX should be a list */
do {
file_count = 0;
scan = scan_dir_open(queue_name);
while ((id = scan_dir_next(scan)) != 0) {
if (mail_open_ok(queue_name, id, &info.st, &path) == MAIL_OPEN_YES) {
pickup_init(&info);
info.path = mystrdup(path);
watchdog_pat();
if (pickup_file(&info) == REMOVE_MESSAGE_FILE) {
if (REMOVE(info.path))
msg_warn("remove %s: %m", info.path);
else
file_count++;
}
pickup_free(&info);
}
}
scan_dir_close(scan);
} while (file_count);
}
/* post_jail_init - drop privileges */
static void post_jail_init(char *unused_name, char **unused_argv)
{
/*
* In case master.cf was not updated for unprivileged service.
*/
if (getuid() != var_owner_uid)
set_ugid(var_owner_uid, var_owner_gid);
/*
* Initialize the receive transparency options: do we want unknown
* recipient checks, do we want address mapping.
*/
pickup_input_transp_mask =
input_transp_mask(VAR_INPUT_TRANSP, var_input_transp);
}
MAIL_VERSION_STAMP_DECLARE;
/* main - pass control to the multi-threaded server skeleton */
int main(int argc, char **argv)
{
static const CONFIG_STR_TABLE str_table[] = {
VAR_FILTER_XPORT, DEF_FILTER_XPORT, &var_filter_xport, 0, 0,
VAR_INPUT_TRANSP, DEF_INPUT_TRANSP, &var_input_transp, 0, 0,
0,
};
/*
* Fingerprint executables and core dumps.
*/
MAIL_VERSION_STAMP_ALLOCATE;
/*
* Use the multi-threaded skeleton, because no-one else should be
* monitoring our service socket while this process runs.
*
* XXX The default watchdog timeout for trigger servers is 1000s, while the
* cleanup server watchdog timeout is $daemon_timeout (i.e. several
* hours). We override the default 1000s timeout to avoid problems with
* slow mail submission. The real problem is of course that the
* single-threaded pickup server is not a good solution for mail
* submissions.
*/
trigger_server_main(argc, argv, pickup_service,
CA_MAIL_SERVER_STR_TABLE(str_table),
CA_MAIL_SERVER_POST_INIT(post_jail_init),
CA_MAIL_SERVER_SOLITARY,
CA_MAIL_SERVER_WATCHDOG(&var_daemon_timeout),
0);
}