Adding upstream version 3.5.24.upstream/3.5.24upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 298 insertions, 0 deletions

diff --git a/src/global/maillog_client.c b/src/global/maillog_client.c
new file mode 100644
index 0000000..50bfbeb
--- /dev/null
+++ b/src/global/maillog_client.c
@@ -0,0 +1,298 @@
+/*++
+/* NAME
+/*	maillog_client 3
+/* SUMMARY
+/*	choose between syslog client and postlog client
+/* SYNOPSIS
+/*	#include <maillog_client.h>
+/*
+/*	int	maillog_client_init(
+/*	const char *progname,
+/*	int	flags)
+/* DESCRIPTION
+/*	maillog_client_init() chooses between logging to the syslog
+/*	service or to the internal postlog service.
+/*
+/*	maillog_client_init() may be called before configuration
+/*	parameters are initialized. During this time, logging is
+/*	controlled by the presence or absence of POSTLOG_SERVICE
+/*	in the process environment (this is ignored if a program
+/*	runs with set-uid or set-gid permissions).
+/*
+/*	maillog_client_init() may also be called after configuration
+/*	parameters are initialized. During this time, logging is
+/*	controlled by the "maillog_file" parameter value.
+/*
+/*	Arguments:
+/* .IP progname
+/*	The program name that will be prepended to logfile records.
+/* .IP flags
+/*	Specify one of the following:
+/* .RS
+/* .IP MAILLOG_CLIENT_FLAG_NONE
+/*	No special processing.
+/* .IP MAILLOG_CLIENT_FLAG_LOGWRITER_FALLBACK
+/*	Try to fall back to writing the "maillog_file" directly,
+/*	if logging to the internal postlog service is enabled, but
+/*	the postlog service is unavailable. If the fallback fails,
+/*	die with a fatal error.
+/* .RE
+/* ENVIRONMENT
+/* .ad
+/* .fi
+/*	When logging to the internal postlog service is enabled,
+/*	each process exports the following information, to help
+/*	initialize the logging in a child process, before the child
+/*	has initialized its configuration parameters.
+/* .IP POSTLOG_SERVICE
+/*	The pathname of the public postlog service endpoint, usually
+/*	"$queue_directory/public/$postlog_service_name".
+/* .IP POSTLOG_HOSTNAME
+/*	The hostname to prepend to information that is sent to the
+/*	internal postlog logging service, usually "$myhostname".
+/* CONFIGURATION PARAMETERS
+/* .ad
+/* .fi
+/* .IP "maillog_file (empty)"
+/*	The name of an optional logfile. If the value is empty, or
+/*	unitialized and the process environment does not specify
+/*	POSTLOG_SERVICE, the program will log to the syslog service
+/*	instead.
+/* .IP "myhostname (default: see postconf -d output)"
+/*	The internet hostname of this mail system.
+/* .IP "postlog_service_name (postlog)"
+/*	The name of the internal postlog logging service.
+/* SEE ALSO
+/*	msg_syslog(3)   syslog client
+/*	msg_logger(3)   internal logger
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this
+/*	software.
+/* AUTHOR(S)
+/*	Wietse Venema
+/*	Google, Inc.
+/*	111 8th Avenue
+/*	New York, NY 10011, USA
+/*--*/
+
+ /*
+  * System library.
+  */
+#include <sys_defs.h>
+#include <stdlib.h>
+#include <string.h>
+
+ /*
+  * Utility library.
+  */
+#include <argv.h>
+#include <logwriter.h>
+#include <msg_logger.h>
+#include <msg_syslog.h>
+#include <safe.h>
+#include <stringops.h>
+
+ /*
+  * Global library.
+  */
+#include <mail_params.h>
+#include <mail_proto.h>
+#include <maillog_client.h>
+#include <msg.h>
+
+ /*
+  * Using logging to debug logging is painful.
+  */
+#define MAILLOG_CLIENT_DEBUG	0
+
+ /*
+  * Application-specific.
+  */
+static int maillog_client_flags;
+
+#define POSTLOG_SERVICE_ENV	"POSTLOG_SERVICE"
+#define POSTLOG_HOSTNAME_ENV	"POSTLOG_HOSTNAME"
+
+/* maillog_client_logwriter_fallback - fall back to logfile writer or bust */
+
+static void maillog_client_logwriter_fallback(const char *text)
+{
+    static int fallback_guard = 0;
+
+    /*
+     * Guard against recursive calls.
+     * 
+     * If an error happened before the maillog_file parameter was initialized,
+     * or if maillog_file logging is disabled, then we cannot fall back to a
+     * logfile. All we can do is to hope that stderr logging will bring out
+     * the bad news.
+     */
+    if (fallback_guard == 0 && var_maillog_file && *var_maillog_file
+	&& logwriter_one_shot(var_maillog_file, text, strlen(text)) < 0) {
+	fallback_guard = 1;
+	msg_fatal("logfile '%s' write error: %m", var_maillog_file);
+    }
+}
+
+/* maillog_client_init - set up syslog or internal log client */
+
+void    maillog_client_init(const char *progname, int flags)
+{
+    char   *import_service_path;
+    char   *import_hostname;
+
+    /*
+     * Crucially, only one logger mode can be in effect at any time,
+     * otherwise postlogd(8) may go into a loop.
+     */
+    enum {
+	MAILLOG_CLIENT_MODE_SYSLOG, MAILLOG_CLIENT_MODE_POSTLOG,
+    }       logger_mode;
+
+    /*
+     * Security: this code may run before the import_environment setting has
+     * taken effect. It has to guard against privilege escalation attacks on
+     * setgid programs, using malicious environment settings.
+     * 
+     * Import the postlog service name and hostname from the environment.
+     * 
+     * - These will be used and kept if the process has not yet initialized its
+     * configuration parameters.
+     * 
+     * - These will be set or updated if the configuration enables postlog
+     * logging.
+     * 
+     * - These will be removed if the configuration does not enable postlog
+     * logging.
+     */
+    if ((import_service_path = safe_getenv(POSTLOG_SERVICE_ENV)) != 0
+	&& *import_service_path == 0)
+	import_service_path = 0;
+    if ((import_hostname = safe_getenv(POSTLOG_HOSTNAME_ENV)) != 0
+	&& *import_hostname == 0)
+	import_hostname = 0;
+
+#if MAILLOG_CLIENT_DEBUG
+#define STRING_OR_NULL(s) ((s) ? (s) : "(null)")
+    msg_syslog_init(progname, LOG_PID, LOG_FACILITY);
+    msg_info("import_service_path=%s", STRING_OR_NULL(import_service_path));
+    msg_info("import_hostname=%s", STRING_OR_NULL(import_hostname));
+#endif
+
+    /*
+     * Before configuration parameters are initialized, the logging mode is
+     * controlled by the presence or absence of POSTLOG_SERVICE in the
+     * process environment. After configuration parameters are initialized,
+     * the logging mode is controlled by the "maillog_file" parameter value.
+     * 
+     * The configured mode may change after a process is started. The
+     * postlogd(8) server will proxy logging to syslogd where needed.
+     */
+    if (var_maillog_file ? *var_maillog_file == 0 : import_service_path == 0) {
+	logger_mode = MAILLOG_CLIENT_MODE_SYSLOG;
+    } else {
+	/* var_maillog_file ? *var_maillog_file : import_service_path != 0 */
+	logger_mode = MAILLOG_CLIENT_MODE_POSTLOG;
+    }
+
+    /*
+     * Postlog logging is enabled. Update the 'progname' as that may have
+     * changed since an earlier call, and update the environment settings if
+     * they differ from configuration settings. This blends two code paths,
+     * one code path where configuration parameters are initialized (the
+     * preferred path), and one code path that uses imports from environment.
+     */
+    if (logger_mode == MAILLOG_CLIENT_MODE_POSTLOG) {
+	char   *myhostname;
+	char   *service_path;
+
+	if (var_maillog_file && *var_maillog_file) {
+	    ARGV   *good_prefixes = argv_split(var_maillog_file_pfxs,
+					       CHARS_COMMA_SP);
+	    char  **cpp;
+
+	    for (cpp = good_prefixes->argv; /* see below */ ; cpp++) {
+		if (*cpp == 0)
+		    msg_fatal("%s value '%s' does not match any prefix in %s",
+			      VAR_MAILLOG_FILE, var_maillog_file,
+			      VAR_MAILLOG_FILE_PFXS);
+		if (strncmp(var_maillog_file, *cpp, strlen(*cpp)) == 0)
+		    break;
+	    }
+	    argv_free(good_prefixes);
+	}
+	if (var_myhostname && *var_myhostname) {
+	    myhostname = var_myhostname;
+	} else if ((myhostname = import_hostname) == 0) {
+	    myhostname = "amnesiac";
+	}
+#if MAILLOG_CLIENT_DEBUG
+	msg_info("myhostname=%s", STRING_OR_NULL(myhostname));
+#endif
+	if (var_postlog_service) {
+	    service_path = concatenate(var_queue_dir, "/", MAIL_CLASS_PUBLIC,
+				       "/", var_postlog_service, (char *) 0);
+	} else {
+	    service_path = import_service_path;
+	}
+	maillog_client_flags = flags;
+	msg_logger_init(progname, myhostname, service_path,
+			(flags & MAILLOG_CLIENT_FLAG_LOGWRITER_FALLBACK) ?
+			maillog_client_logwriter_fallback :
+			(MSG_LOGGER_FALLBACK_FN) 0);
+
+	/*
+	 * Export or update the exported postlog service pathname and the
+	 * hostname, so that a child process can bootstrap postlog logging
+	 * before it has processed main.cf and command-line options.
+	 */
+	if (import_service_path == 0
+	    || strcmp(service_path, import_service_path) != 0) {
+#if MAILLOG_CLIENT_DEBUG
+	    msg_info("export %s=%s", POSTLOG_SERVICE_ENV, service_path);
+#endif
+	    if (setenv(POSTLOG_SERVICE_ENV, service_path, 1) < 0)
+		msg_fatal("setenv: %m");
+	}
+	if (import_hostname == 0 || strcmp(myhostname, import_hostname) != 0) {
+#if MAILLOG_CLIENT_DEBUG
+	    msg_info("export %s=%s", POSTLOG_HOSTNAME_ENV, myhostname);
+#endif
+	    if (setenv(POSTLOG_HOSTNAME_ENV, myhostname, 1) < 0)
+		msg_fatal("setenv: %m");
+	}
+	if (service_path != import_service_path)
+	    myfree(service_path);
+	msg_logger_control(CA_MSG_LOGGER_CTL_CONNECT_NOW,
+			   CA_MSG_LOGGER_CTL_END);
+    }
+
+    /*
+     * Postlog logging is disabled. Silence the msg_logger client, and remove
+     * the environment settings that bootstrap postlog logging in a child
+     * process.
+     */
+    else {
+	msg_logger_control(CA_MSG_LOGGER_CTL_DISABLE, CA_MSG_LOGGER_CTL_END);
+	if ((import_service_path && unsetenv(POSTLOG_SERVICE_ENV))
+	    || (import_hostname && unsetenv(POSTLOG_HOSTNAME_ENV)))
+	    msg_fatal("unsetenv: %m");
+    }
+
+    /*
+     * Syslog logging is enabled. Update the 'progname' as that may have
+     * changed since an earlier call.
+     */
+    if (logger_mode == MAILLOG_CLIENT_MODE_SYSLOG) {
+	msg_syslog_init(progname, LOG_PID, LOG_FACILITY);
+    }
+
+    /*
+     * Syslog logging is disabled, silence the syslog client.
+     */
+    else {
+	msg_syslog_disable();
+    }
+}