util-linux/misc-utils/logger.c

/*
 * Copyright (c) 1983, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
 *
 * 1999-02-22 Arkadiusz Miśkiewicz <misiek@pld.ORG.PL>
 * - added Native Language Support
 * Sun Mar 21 1999 - Arnaldo Carvalho de Melo <acme@conectiva.com.br>
 * - fixed strerr(errno) in gettext calls
 */

#include <errno.h>
#include <limits.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/time.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <getopt.h>
#include <pwd.h>
#include <signal.h>
#include <sys/uio.h>

#include "all-io.h"
#include "c.h"
#include "closestream.h"
#include "nls.h"
#include "pathnames.h"
#include "strutils.h"
#include "xalloc.h"
#include "strv.h"
#include "list.h"

#define	SYSLOG_NAMES
#include <syslog.h>

#ifdef HAVE_LIBSYSTEMD
# define SD_JOURNAL_SUPPRESS_LOCATION
# include <systemd/sd-daemon.h>
# include <systemd/sd-journal.h>
#endif

#ifdef HAVE_SYS_TIMEX_H
# include <sys/timex.h>
#endif

enum {
	TYPE_UDP = (1 << 1),
	TYPE_TCP = (1 << 2),
	ALL_TYPES = TYPE_UDP | TYPE_TCP
};

enum {
	AF_UNIX_ERRORS_OFF = 0,
	AF_UNIX_ERRORS_ON,
	AF_UNIX_ERRORS_AUTO
};

enum {
	OPT_PRIO_PREFIX = CHAR_MAX + 1,
	OPT_JOURNALD,
	OPT_RFC3164,
	OPT_RFC5424,
	OPT_SOCKET_ERRORS,
	OPT_MSGID,
	OPT_NOACT,
	OPT_ID,
	OPT_STRUCTURED_DATA_ID,
	OPT_STRUCTURED_DATA_PARAM,
	OPT_OCTET_COUNT
};

/* rfc5424 structured data */
struct structured_data {
	char *id;		/* SD-ID */
	char **params;		/* array with SD-PARAMs */

	struct list_head	sds;
};

struct logger_ctl {
	int fd;
	int pri;
	pid_t pid;			/* zero when unwanted */
	char *hdr;			/* the syslog header (based on protocol) */
	char const *tag;
	char *msgid;
	char *unix_socket;		/* -u <path> or default to _PATH_DEVLOG */
	char *server;
	char *port;
	int socket_type;
	size_t max_message_size;
	struct list_head user_sds;	/* user defined rfc5424 structured data */
	struct list_head reserved_sds;	/* standard rfc5424 structured data */

	void (*syslogfp)(struct logger_ctl *ctl);

	unsigned int
			unix_socket_errors:1,	/* whether to report or not errors */
			noact:1,		/* do not write to sockets */
			prio_prefix:1,		/* read priority from input */
			stderr_printout:1,	/* output message to stderr */
			rfc5424_time:1,		/* include time stamp */
			rfc5424_tq:1,		/* include time quality markup */
			rfc5424_host:1,		/* include hostname */
			skip_empty_lines:1,	/* do not send empty lines when processing files */
			octet_count:1;		/* use RFC6587 octet counting */
};

#define is_connected(_ctl)	((_ctl)->fd >= 0)
static void logger_reopen(struct logger_ctl *ctl);

/*
 * For tests we want to be able to control datetime outputs
 */
#ifdef TEST_LOGGER
static inline int logger_gettimeofday(struct timeval *tv, struct timezone *tz)
{
	char *str = getenv("LOGGER_TEST_TIMEOFDAY");
	uintmax_t sec, usec;

	if (str && sscanf(str, "%ju.%ju", &sec, &usec) == 2) {
		tv->tv_sec = sec;
		tv->tv_usec = usec;
		return tv->tv_sec >= 0 && tv->tv_usec >= 0 ? 0 : -EINVAL;
	}

	return gettimeofday(tv, tz);
}

static inline char *logger_xgethostname(void)
{
	char *str = getenv("LOGGER_TEST_HOSTNAME");
	return str ? xstrdup(str) : xgethostname();
}

static inline pid_t logger_getpid(void)
{
	char *str = getenv("LOGGER_TEST_GETPID");
	unsigned int pid;

	if (str && sscanf(str, "%u", &pid) == 1)
		return pid;
	return getpid();
}


#undef HAVE_NTP_GETTIME		/* force to default non-NTP */

#else /* !TEST_LOGGER */
# define logger_gettimeofday(x, y)	gettimeofday(x, y)
# define logger_xgethostname		xgethostname
# define logger_getpid			getpid
#endif


static int decode(const char *name, const CODE *codetab)
{
	register const CODE *c;

	if (name == NULL || *name == '\0')
		return -1;
	if (isdigit(*name)) {
		int num;
		char *end = NULL;

		errno = 0;
		num = strtol(name, &end, 10);
		if (errno || name == end || (end && *end))
			return -1;
		for (c = codetab; c->c_name; c++)
			if (num == c->c_val)
				return num;
		return -1;
	}
	for (c = codetab; c->c_name; c++)
		if (!strcasecmp(name, c->c_name))
			return (c->c_val);

	return -1;
}

static int pencode(char *s)
{
	int facility, level;
	char *separator;

	assert(s);

	separator = strchr(s, '.');
	if (separator) {
		*separator = '\0';
		facility = decode(s, facilitynames);
		if (facility < 0)
			errx(EXIT_FAILURE, _("unknown facility name: %s"), s);
		s = ++separator;
	} else
		facility = LOG_USER;
	level = decode(s, prioritynames);
	if (level < 0)
		errx(EXIT_FAILURE, _("unknown priority name: %s"), s);
	if (facility == LOG_KERN)
		facility = LOG_USER;	/* kern is forbidden */
	return ((level & LOG_PRIMASK) | (facility & LOG_FACMASK));
}

static int unix_socket(struct logger_ctl *ctl, const char *path, int *socket_type)
{
	int fd = -1, i, type = -1;
	static struct sockaddr_un s_addr;	/* AF_UNIX address of local logger */

	if (strlen(path) >= sizeof(s_addr.sun_path))
		errx(EXIT_FAILURE, _("openlog %s: pathname too long"), path);

	s_addr.sun_family = AF_UNIX;
	strcpy(s_addr.sun_path, path);

	for (i = 2; i; i--) {
		int st = -1;

		if (i == 2 && *socket_type & TYPE_UDP) {
			st = SOCK_DGRAM;
			type = TYPE_UDP;
		}
		if (i == 1 && *socket_type & TYPE_TCP) {
			st = SOCK_STREAM;
			type = TYPE_TCP;
		}
		if (st == -1 || (fd = socket(AF_UNIX, st, 0)) == -1)
			continue;
		if (connect(fd, (struct sockaddr *)&s_addr, sizeof(s_addr)) == -1) {
			close(fd);
			continue;
		}
		break;
	}

	if (i == 0) {
		if (ctl->unix_socket_errors)
			err(EXIT_FAILURE, _("socket %s"), path);

		/* write_output() will try to reconnect */
		return -1;
	}

	/* replace ALL_TYPES with the real TYPE_* */
	if (type > 0 && type != *socket_type)
		*socket_type = type;
	return fd;
}

static int inet_socket(const char *servername, const char *port, int *socket_type)
{
	int fd, errcode, i, type = -1;
	struct addrinfo hints, *res;
	const char *p = port;

	for (i = 2; i; i--) {
		memset(&hints, 0, sizeof(hints));
		if (i == 2 && *socket_type & TYPE_UDP) {
			hints.ai_socktype = SOCK_DGRAM;
			type = TYPE_UDP;
			if (port == NULL)
				p = "syslog";
		}
		if (i == 1 && *socket_type & TYPE_TCP) {
			hints.ai_socktype = SOCK_STREAM;
			type = TYPE_TCP;
			if (port == NULL)
				p = "syslog-conn";
		}
		if (hints.ai_socktype == 0)
			continue;
		hints.ai_family = AF_UNSPEC;
		errcode = getaddrinfo(servername, p, &hints, &res);
		if (errcode != 0)
			errx(EXIT_FAILURE, _("failed to resolve name %s port %s: %s"),
			     servername, p, gai_strerror(errcode));
		if ((fd = socket(res->ai_family, res->ai_socktype, res->ai_protocol)) == -1) {
			freeaddrinfo(res);
			continue;
		}
		if (connect(fd, res->ai_addr, res->ai_addrlen) == -1) {
			freeaddrinfo(res);
			close(fd);
			continue;
		}

		freeaddrinfo(res);
		break;
	}

	if (i == 0)
		errx(EXIT_FAILURE, _("failed to connect to %s port %s"), servername, p);

	/* replace ALL_TYPES with the real TYPE_* */
	if (type > 0 && type != *socket_type)
		*socket_type = type;
	return fd;
}

#ifdef HAVE_LIBSYSTEMD
static int journald_entry(struct logger_ctl *ctl, FILE *fp)
{
	struct iovec *iovec;
	char *buf = NULL;
	ssize_t sz;
	int n, lines = 0, vectors = 8, ret = 0, msgline = -1;
	size_t dummy = 0;

	iovec = xmalloc(vectors * sizeof(struct iovec));
	while (1) {
		buf = NULL;
		sz = getline(&buf, &dummy, fp);
		if (sz == -1 ||
		   (sz = rtrim_whitespace((unsigned char *) buf)) == 0) {
			free(buf);
			break;
		}

		if (strncmp(buf, "MESSAGE=", 8) == 0) {
			if (msgline == -1)
				msgline = lines;	/* remember the first message */
			else {
				char *p = xrealloc(iovec[msgline].iov_base,
						   iovec[msgline].iov_len + sz - 8 + 2);

				iovec[msgline].iov_base = p;
				p += iovec[msgline].iov_len;
				*p++ = '\n';
				memcpy(p, buf + 8, sz - 8);
				free(buf);

				iovec[msgline].iov_len += sz - 8 + 1;
				continue;
			}
		}

		if (lines == vectors) {
			vectors *= 2;
			if (IOV_MAX < vectors)
				errx(EXIT_FAILURE, _("maximum input lines (%d) exceeded"), IOV_MAX);
			iovec = xrealloc(iovec, vectors * sizeof(struct iovec));
		}
		iovec[lines].iov_base = buf;
		iovec[lines].iov_len = sz;
		++lines;
	}

	if (!ctl->noact)
		ret = sd_journal_sendv(iovec, lines);
	if (ctl->stderr_printout) {
		for (n = 0; n < lines; n++)
			fprintf(stderr, "%s\n", (char *) iovec[n].iov_base);
	}
	for (n = 0; n < lines; n++)
		free(iovec[n].iov_base);
	free(iovec);
	return ret;
}
#endif

static char const *xgetlogin(void)
{
	char const *cp;
	struct passwd *pw;

	if (!(cp = getlogin()) || !*cp)
		cp = (pw = getpwuid(geteuid()))? pw->pw_name : "<someone>";
	return cp;
}

/* this creates a timestamp based on current time according to the
 * fine rules of RFC3164, most importantly it ensures in a portable
 * way that the month day is correctly written (with a SP instead
 * of a leading 0). The function uses a static buffer which is
 * overwritten on the next call (just like ctime() does).
 */
static char const *rfc3164_current_time(void)
{
	static char time[32];
	struct timeval tv;
	struct tm tm;
	static char const * const monthnames[] = {
		"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug",
		"Sep", "Oct", "Nov", "Dec"
	};

	logger_gettimeofday(&tv, NULL);
	localtime_r(&tv.tv_sec, &tm);
	snprintf(time, sizeof(time),"%s %2d %2.2d:%2.2d:%2.2d",
		monthnames[tm.tm_mon], tm.tm_mday,
		tm.tm_hour, tm.tm_min, tm.tm_sec);
	return time;
}

#define next_iovec(ary, idx) __extension__ ({		\
		assert(ARRAY_SIZE(ary) > (size_t)idx);	\
		assert(idx >= 0);			\
		&ary[idx++];				\
})

#define iovec_add_string(ary, idx, str, len)		\
	do {						\
		struct iovec *v = next_iovec(ary, idx);	\
		v->iov_base = (void *) str;		\
		v->iov_len = len ? len : strlen(str);	\
	} while (0)

#define iovec_memcmp(ary, idx, str, len)		\
		memcmp((ary)[(idx) - 1].iov_base, str, len)

/* writes generated buffer to desired destination. For TCP syslog,
 * we use RFC6587 octet-stuffing (unless octet-counting is selected).
 * This is not great, but doing full blown RFC5425 (TLS) looks like
 * it is too much for the logger utility. If octet-counting is
 * selected, we use that.
 */
static void write_output(struct logger_ctl *ctl, const char *const msg)
{
	struct iovec iov[4];
	int iovlen = 0;
	char *octet = NULL;

	/* initial connect failed? */
	if (!ctl->noact && !is_connected(ctl))
		logger_reopen(ctl);

	/* 1) octen count */
	if (ctl->octet_count) {
		size_t len = xasprintf(&octet, "%zu ", strlen(ctl->hdr) + strlen(msg));
		iovec_add_string(iov, iovlen, octet, len);
	}

	/* 2) header */
	iovec_add_string(iov, iovlen, ctl->hdr, 0);

	/* 3) message */
	iovec_add_string(iov, iovlen, msg, 0);

	if (!ctl->noact && is_connected(ctl)) {
		struct msghdr message = { 0 };
#ifdef SCM_CREDENTIALS
		struct cmsghdr *cmhp;
		struct ucred *cred;
		union {
			struct cmsghdr cmh;
			char   control[CMSG_SPACE(sizeof(struct ucred))];
		} cbuf;
#endif

		/* 4) add extra \n to make sure message is terminated */
		if ((ctl->socket_type == TYPE_TCP) && !ctl->octet_count)
			iovec_add_string(iov, iovlen, "\n", 1);

		message.msg_iov = iov;
		message.msg_iovlen = iovlen;

#ifdef SCM_CREDENTIALS
		/* syslog/journald may follow local socket credentials rather
		 * than in the message PID. If we use --id as root than we can
		 * force kernel to accept another valid PID than the real logger(1)
		 * PID.
		 */
		if (ctl->pid && !ctl->server && ctl->pid != getpid()
		    && geteuid() == 0 && kill(ctl->pid, 0) == 0) {

			message.msg_control = cbuf.control;
			message.msg_controllen = CMSG_SPACE(sizeof(struct ucred));

			cmhp = CMSG_FIRSTHDR(&message);
			cmhp->cmsg_len = CMSG_LEN(sizeof(struct ucred));
			cmhp->cmsg_level = SOL_SOCKET;
			cmhp->cmsg_type = SCM_CREDENTIALS;
			cred = (struct ucred *) CMSG_DATA(cmhp);

			cred->pid = ctl->pid;
		}
#endif
		/* Note that logger(1) maybe executed for long time (as pipe
		 * reader) and connection endpoint (syslogd) may be restarted.
		 *
		 * The libc syslog() function reconnects on failed send().
		 * Let's do the same to be robust.    [kzak -- Oct 2017]
		 *
		 * MSG_NOSIGNAL is POSIX.1-2008 compatible, but it for example
		 * not supported by apple-darwin15.6.0.
		 */
#ifndef MSG_NOSIGNAL
# define MSG_NOSIGNAL 0
#endif
		if (sendmsg(ctl->fd, &message, MSG_NOSIGNAL) < 0) {
			logger_reopen(ctl);
			if (sendmsg(ctl->fd, &message, MSG_NOSIGNAL) < 0)
				warn(_("send message failed"));
		}
	}

	if (ctl->stderr_printout) {
		/* make sure it's terminated for stderr */
		if (iovec_memcmp(iov, iovlen, "\n", 1) != 0)
			iovec_add_string(iov, iovlen, "\n", 1);

		ignore_result( writev(STDERR_FILENO, iov, iovlen) );
	}

	free(octet);
}

#define NILVALUE "-"
static void syslog_rfc3164_header(struct logger_ctl *const ctl)
{
	char pid[30], *hostname;

	*pid = '\0';
	if (ctl->pid)
		snprintf(pid, sizeof(pid), "[%d]", ctl->pid);

	if ((hostname = logger_xgethostname())) {
		char *dot = strchr(hostname, '.');
		if (dot)
			*dot = '\0';
	} else
		hostname = xstrdup(NILVALUE);

	xasprintf(&ctl->hdr, "<%d>%.15s %s %.200s%s: ",
		 ctl->pri, rfc3164_current_time(), hostname, ctl->tag, pid);

	free(hostname);
}

static inline struct list_head *get_user_structured_data(struct logger_ctl *ctl)
{
	return &ctl->user_sds;
}

static inline struct list_head *get_reserved_structured_data(struct logger_ctl *ctl)
{
	return &ctl->reserved_sds;
}

static int has_structured_data_id(struct list_head *ls, const char *id)
{
	struct list_head *p;

	if (!ls || list_empty(ls))
		return 0;

	list_for_each(p, ls) {
		struct structured_data *sd = list_entry(p, struct structured_data, sds);
		if (sd-&