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Diffstat (limited to 'src/postlogd/postlogd.c')
| -rw-r--r-- | src/postlogd/postlogd.c | 267 |
1 files changed, 267 insertions, 0 deletions
diff --git a/src/postlogd/postlogd.c b/src/postlogd/postlogd.c new file mode 100644 index 0000000..4c6db63 --- /dev/null +++ b/src/postlogd/postlogd.c @@ -0,0 +1,267 @@ +/*++ +/* NAME +/* postlogd 8 +/* SUMMARY +/* Postfix internal log server +/* SYNOPSIS +/* \fBpostlogd\fR [generic Postfix daemon options] +/* DESCRIPTION +/* This program logs events on behalf of Postfix programs +/* when the maillog configuration parameter specifies a non-empty +/* value. +/* BUGS +/* Non-daemon Postfix programs don't know that they should log +/* to the internal logging service before they have processed +/* command-line options and main.cf parameters. These programs +/* still log earlier events to the syslog service. +/* +/* If Postfix is down, the non-daemon programs \fBpostfix\fR(1), +/* \fBpostsuper\fR(1), \fBpostmulti\fR(1), and \fBpostlog\fR(1), +/* will log directly to \fB$maillog_file\fR. These programs +/* expect to run with root privileges, for example during +/* Postfix start-up, reload, or shutdown. +/* +/* Other non-daemon Postfix programs will never write directly to +/* \fB$maillog_file\fR (also, logging to stdout would interfere +/* with the operation of some of these programs). These programs +/* can log to \fBpostlogd\fR(8) if they are run by the super-user, +/* or if their executable file has set-gid permission. Do not +/* set this permission on programs other than \fBpostdrop\fR(1) +/* and \fBpostqueue\fR(1). +/* CONFIGURATION PARAMETERS +/* .ad +/* .fi +/* Changes to \fBmain.cf\fR are picked up automatically, as +/* \fBpostlogd\fR(8) processes run for only a limited amount +/* of time. Use the command "\fBpostfix reload\fR" to speed +/* up a change. +/* +/* The text below provides only a parameter summary. See +/* \fBpostconf\fR(5) for more details including examples. +/* .IP "\fBconfig_directory (see 'postconf -d' output)\fR" +/* The default location of the Postfix main.cf and master.cf +/* configuration files. +/* .IP "\fBmaillog_file (empty)\fR" +/* The name of an optional logfile that is written by the Postfix +/* \fBpostlogd\fR(8) service. +/* .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 "\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". +/* .IP "\fBservice_name (read-only)\fR" +/* The master.cf service name of a Postfix daemon process. +/* .IP "\fBpostlogd_watchdog_timeout (10s)\fR" +/* How much time a \fBpostlogd\fR(8) process may take to process a request +/* before it is terminated by a built-in watchdog timer. +/* SEE ALSO +/* postconf(5), configuration parameters +/* syslogd(8), system logging +/* README_FILES +/* .ad +/* .fi +/* Use "\fBpostconf readme_directory\fR" or +/* "\fBpostconf html_directory\fR" to locate this information. +/* .na +/* .nf +/* MAILLOG_README, Postfix logging to file or stdout +/* LICENSE +/* .ad +/* .fi +/* The Secure Mailer license must be distributed with this software. +/* HISTORY +/* .ad +/* .fi +/* This service was introduced with Postfix version 3.4. +/* AUTHOR(S) +/* Wietse Venema +/* Google, Inc. +/* 111 8th Avenue +/* New York, NY 10011, USA +/*--*/ + + /* + * System library. + */ +#include <sys_defs.h> + + /* + * Utility library. + */ +#include <logwriter.h> +#include <msg.h> +#include <msg_logger.h> +#include <stringops.h> +#include <vstream.h> + + /* + * Global library. + */ +#include <mail_params.h> +#include <mail_task.h> +#include <mail_version.h> +#include <maillog_client.h> + + /* + * Server skeleton. + */ +#include <mail_server.h> + + /* + * Tunable parameters. + */ +int var_postlogd_watchdog; + + /* + * Silly little macros. + */ +#define STR(x) vstring_str(x) +#define LEN(x) VSTRING_LEN(x) + + /* + * Logfile stream. + */ +static VSTREAM *postlogd_stream = 0; + +/* postlogd_fallback - log messages from postlogd(8) itself */ + +static void postlogd_fallback(const char *buf) +{ + (void) logwriter_write(postlogd_stream, buf, strlen(buf)); +} + +/* postlogd_service - perform service for client */ + +static void postlogd_service(char *buf, ssize_t len, char *unused_service, + char **unused_argv) +{ + + if (postlogd_stream) { + (void) logwriter_write(postlogd_stream, buf, len); + } + + /* + * After a configuration change that removes the maillog_file pathname, + * this service may still receive messages (after "postfix reload" or + * after process refresh) from programs that use the old maillog_file + * setting. Redirect those messages to the current logging mechanism. + */ + else { + char *bp = buf; + char *progname_pid; + + /* + * Avoid surprises: strip off the date, time, host, and program[pid]: + * prefix that were prepended by msg_logger(3). Then, hope that the + * current logging driver suppresses its own PID, when it sees that + * there is a PID embedded in the 'program name'. + */ + (void) mystrtok(&bp, CHARS_SPACE); /* month */ + (void) mystrtok(&bp, CHARS_SPACE); /* day */ + (void) mystrtok(&bp, CHARS_SPACE); /* time */ + (void) mystrtok(&bp, CHARS_SPACE); /* host */ + progname_pid = mystrtok(&bp, ":" CHARS_SPACE); /* name[pid] sans ':' */ + bp += strspn(bp, CHARS_SPACE); + if (progname_pid) + maillog_client_init(progname_pid, MAILLOG_CLIENT_FLAG_NONE); + msg_info("%.*s", (int) (len - (bp - buf)), bp); + + /* + * Restore the program name, in case postlogd(8) needs to log + * something about itself. We have to call maillog_client_init() in + * any case, because neither msg_syslog_init() nor openlog() make a + * copy of the name argument. We can't leave that pointing into the + * middle of the above message buffer. + */ + maillog_client_init(mail_task((char *) 0), MAILLOG_CLIENT_FLAG_NONE); + } +} + +/* pre_jail_init - pre-jail handling */ + +static void pre_jail_init(char *unused_service_name, char **argv) +{ + + /* + * During process initialization, the postlogd daemon will log events to + * the postlog socket, so that they can be logged to file later. Once the + * postlogd daemon is handling requests, it will stop logging to the + * postlog socket and will instead write to the logfile, to avoid + * infinite recursion. + */ + + /* + * Sanity check. This service takes no command-line arguments. + */ + if (argv[0]) + msg_fatal("unexpected command-line argument: %s", argv[0]); + + /* + * After a configuration change that removes the maillog_file pathname, + * this service may still receive messages from processes that still use + * the old configuration. Those messages will have to be redirected to + * the current logging subsystem. + */ + if (*var_maillog_file != 0) { + + /* + * Instantiate the logwriter or bust. + */ + postlogd_stream = logwriter_open_or_die(var_maillog_file); + + /* + * Inform the msg_logger client to stop using the postlog socket, and + * to call our logwriter. + */ + msg_logger_control(CA_MSG_LOGGER_CTL_FALLBACK_ONLY, + CA_MSG_LOGGER_CTL_FALLBACK_FN(postlogd_fallback), + CA_MSG_LOGGER_CTL_END); + } +} + +/* post_jail_init - post-jail initialization */ + +static void post_jail_init(char *unused_name, char **unused_argv) +{ + + /* + * Prevent automatic process suicide after a limited number of client + * requests. It is OK to terminate after a limited amount of idle time. + */ + var_use_limit = 0; +} + +MAIL_VERSION_STAMP_DECLARE; + +/* main - pass control to the multi-threaded skeleton */ + +int main(int argc, char **argv) +{ + static const CONFIG_TIME_TABLE time_table[] = { + VAR_POSTLOGD_WATCHDOG, DEF_POSTLOGD_WATCHDOG, &var_postlogd_watchdog, 10, 0, + 0, + }; + + /* + * Fingerprint executables and core dumps. + */ + MAIL_VERSION_STAMP_ALLOCATE; + + /* + * This is a datagram service, not a stream service, so that postlogd can + * restart immediately after "postfix reload" without requiring clients + * to resend messages. Those messages remain queued in the kernel until a + * new postlogd process retrieves them. It would be unreasonable to + * require that clients retransmit logs, especially in the case of a + * fatal or panic error. + */ + dgram_server_main(argc, argv, postlogd_service, + CA_MAIL_SERVER_TIME_TABLE(time_table), + CA_MAIL_SERVER_PRE_INIT(pre_jail_init), + CA_MAIL_SERVER_POST_INIT(post_jail_init), + CA_MAIL_SERVER_SOLITARY, + CA_MAIL_SERVER_WATCHDOG(&var_postlogd_watchdog), + 0); +} |