d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
freebsd-skq/libxo/xo_syslog.c
David E. O'Brien 5ffdcf4ecc More closely match the 
https://github.com/Juniper/libxo/releases/download/0.4.5/libxo-0.4.5.tar.gz
tarball.

Reviewed by: phil
2016-03-16 23:39:55 +00:00

707 lines
19 KiB
C
Raw Blame History

/*
* Copyright (c) 2015, Juniper Networks, Inc.
* All rights reserved.
* This SOFTWARE is licensed under the LICENSE provided in the
* ../Copyright file. By downloading, installing, copying, or otherwise
* using the SOFTWARE, you agree to be bound by the terms of that
* LICENSE.
* Phil Shafer, June 2015
*/
/*
* Portions of this file are:
* Copyright (c) 1983, 1988, 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.
* 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.
*/
#include <sys/cdefs.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/syslog.h>
#include <sys/uio.h>
#include <sys/un.h>
#include <netdb.h>
#include <errno.h>
#include <fcntl.h>
#include <paths.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <stdarg.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/sysctl.h>
#include "xo_config.h"
#include "xo.h"
#include "xo_encoder.h" /* For xo_realloc */
#include "xo_buf.h"
/*
* SYSLOG (RFC 5424) requires an enterprise identifier. This turns
* out to be a fickle little issue. For a single-vendor box, the
* system should have a single EID that all software can use. When
* VendorX turns FreeBSD into a product, all software (kernel and
* utilities) should report VendorX's EID. But when software is
* installed on top of an external operating system, the application
* should report it's own EID, distinct from the base OS.
*
* To make this happen, the kernel should support a sysctl to assign a
* custom enterprise-id ("kern.syslog.enterprise_id"). libxo then
* allows an application to set a custom EID to override that system
* wide value, if needed.
*
* We try to set the stock IANA assigned Enterprise ID value for the
* vendors we know about (FreeBSD, macosx), but fallback to the
* "example" EID defined by IANA. See:
* https://www.iana.org/assignments/enterprise-numbers/enterprise-numbers
*/
#define XO_SYSLOG_ENTERPRISE_ID "kern.syslog.enterprise_id"
#if defined(__FreeBSD__)
#define XO_DEFAULT_EID 2238
#elif defined(__macosx__)
#define XO_DEFAULT_EID 63
#else
#define XO_DEFAULT_EID 32473 /* Fallback to the "example" number */
#endif
#ifdef _SC_HOST_NAME_MAX
#define HOST_NAME_MAX _SC_HOST_NAME_MAX
#else
#define HOST_NAME_MAX 255
#endif /* _SC_HOST_NAME_MAX */
#ifndef UNUSED
#define UNUSED __attribute__ ((__unused__))
#endif /* UNUSED */
static int xo_logfile = -1; /* fd for log */
static int xo_status; /* connection xo_status */
static int xo_opened; /* have done openlog() */
static int xo_logstat = 0; /* xo_status bits, set by openlog() */
static const char *xo_logtag = NULL; /* string to tag the entry with */
static int xo_logfacility = LOG_USER; /* default facility code */
static int xo_logmask = 0xff; /* mask of priorities to be logged */
static pthread_mutex_t xo_syslog_mutex UNUSED = PTHREAD_MUTEX_INITIALIZER;
static int xo_unit_test; /* Fake data for unit test */
#define REAL_VOID(_x) \
do { int really_ignored = _x; if (really_ignored) { }} while (0)
#if !defined(HAVE_DECL___ISTHREADED) || !HAVE_DECL___ISTHREADED
#define __isthreaded 1
#endif
#define THREAD_LOCK() \
do { \
if (__isthreaded) pthread_mutex_lock(&xo_syslog_mutex); \
} while(0)
#define THREAD_UNLOCK() \
do { \
if (__isthreaded) pthread_mutex_unlock(&xo_syslog_mutex); \
} while(0)
static void xo_disconnect_log(void); /* disconnect from syslogd */
static void xo_connect_log(void); /* (re)connect to syslogd */
static void xo_open_log_unlocked(const char *, int, int);
enum {
NOCONN = 0,
CONNDEF,
CONNPRIV,
};
static xo_syslog_open_t xo_syslog_open;
static xo_syslog_send_t xo_syslog_send;
static xo_syslog_close_t xo_syslog_close;
static char xo_syslog_enterprise_id[12];
/*
* Record an enterprise ID, which functions as a namespace for syslog
* messages. The value is pre-formatted into a string. This allows
* applications to customize their syslog message set, when needed.
*/
void
xo_set_syslog_enterprise_id (unsigned short eid)
{
snprintf(xo_syslog_enterprise_id, sizeof(xo_syslog_enterprise_id),
"%u", eid);
}
/*
* Handle the work of transmitting the syslog message
*/
static void
xo_send_syslog (char *full_msg, char *v0_hdr,
char *text_only)
{
if (xo_syslog_send) {
xo_syslog_send(full_msg, v0_hdr, text_only);
return;
}
int fd;
int full_len = strlen(full_msg);
/* Output to stderr if requested. */
if (xo_logstat & LOG_PERROR) {
struct iovec iov[3];
struct iovec *v = iov;
char newline[] = "\n";
v->iov_base = v0_hdr;
v->iov_len = strlen(v0_hdr);
v += 1;
v->iov_base = text_only;
v->iov_len = strlen(text_only);
v += 1;
v->iov_base = newline;
v->iov_len = 1;
v += 1;
REAL_VOID(writev(STDERR_FILENO, iov, 3));
}
/* Get connected, output the message to the local logger. */
if (!xo_opened)
xo_open_log_unlocked(xo_logtag, xo_logstat | LOG_NDELAY, 0);
xo_connect_log();
/*
* If the send() fails, there are two likely scenarios:
* 1) syslogd was restarted
* 2) /var/run/log is out of socket buffer space, which
* in most cases means local DoS.
* If the error does not indicate a full buffer, we address
* case #1 by attempting to reconnect to /var/run/log[priv]
* and resending the message once.
*
* If we are working with a privileged socket, the retry
* attempts end there, because we don't want to freeze a
* critical application like su(1) or sshd(8).
*
* Otherwise, we address case #2 by repeatedly retrying the
* send() to give syslogd a chance to empty its socket buffer.
*/
if (send(xo_logfile, full_msg, full_len, 0) < 0) {
if (errno != ENOBUFS) {
/*
* Scenario 1: syslogd was restarted
* reconnect and resend once
*/
xo_disconnect_log();
xo_connect_log();
if (send(xo_logfile, full_msg, full_len, 0) >= 0) {
return;
}
/*
* if the resend failed, fall through to
* possible scenario 2
*/
}
while (errno == ENOBUFS) {
/*
* Scenario 2: out of socket buffer space
* possible DoS, fail fast on a privileged
* socket
*/
if (xo_status == CONNPRIV)
break;
usleep(1);
if (send(xo_logfile, full_msg, full_len, 0) >= 0) {
return;
}
}
} else {
return;
}
/*
* Output the message to the console; try not to block
* as a blocking console should not stop other processes.
* Make sure the error reported is the one from the syslogd failure.
*/
int flags = O_WRONLY | O_NONBLOCK;
#ifdef O_CLOEXEC
flags |= O_CLOEXEC;
#endif /* O_CLOEXEC */
if (xo_logstat & LOG_CONS
&& (fd = open(_PATH_CONSOLE, flags, 0)) >= 0) {
struct iovec iov[2];
struct iovec *v = iov;
char crnl[] = "\r\n";
char *p;
p = strchr(full_msg, '>') + 1;
v->iov_base = p;
v->iov_len = full_len - (p - full_msg);
++v;
v->iov_base = crnl;
v->iov_len = 2;
REAL_VOID(writev(fd, iov, 2));
(void) close(fd);
}
}
/* Should be called with mutex acquired */
static void
xo_disconnect_log (void)
{
if (xo_syslog_close) {
xo_syslog_close();
return;
}
/*
* If the user closed the FD and opened another in the same slot,
* that's their problem. They should close it before calling on
* system services.
*/
if (xo_logfile != -1) {
close(xo_logfile);
xo_logfile = -1;
}
xo_status = NOCONN; /* retry connect */
}
/* Should be called with mutex acquired */
static void
xo_connect_log (void)
{
if (xo_syslog_open) {
xo_syslog_open();
return;
}
struct sockaddr_un saddr; /* AF_UNIX address of local logger */
if (xo_logfile == -1) {
int flags = SOCK_DGRAM;
#ifdef SOCK_CLOEXEC
flags |= SOCK_CLOEXEC;
#endif /* SOCK_CLOEXEC */
if ((xo_logfile = socket(AF_UNIX, flags, 0)) == -1)
return;
}
if (xo_logfile != -1 && xo_status == NOCONN) {
#ifdef HAVE_SUN_LEN
saddr.sun_len = sizeof(saddr);
#endif /* HAVE_SUN_LEN */
saddr.sun_family = AF_UNIX;
/*
* First try privileged socket. If no success,
* then try default socket.
*/
#ifdef _PATH_LOG_PRIV
(void) strncpy(saddr.sun_path, _PATH_LOG_PRIV,
sizeof saddr.sun_path);
if (connect(xo_logfile, (struct sockaddr *) &saddr,
sizeof(saddr)) != -1)
xo_status = CONNPRIV;
#endif /* _PATH_LOG_PRIV */
#ifdef _PATH_LOG
if (xo_status == NOCONN) {
(void) strncpy(saddr.sun_path, _PATH_LOG,
sizeof saddr.sun_path);
if (connect(xo_logfile, (struct sockaddr *)&saddr,
sizeof(saddr)) != -1)
xo_status = CONNDEF;
}
#endif /* _PATH_LOG */
#ifdef _PATH_OLDLOG
if (xo_status == NOCONN) {
/*
* Try the old "/dev/log" path, for backward
* compatibility.
*/
(void) strncpy(saddr.sun_path, _PATH_OLDLOG,
sizeof saddr.sun_path);
if (connect(xo_logfile, (struct sockaddr *)&saddr,
sizeof(saddr)) != -1)
xo_status = CONNDEF;
}
#endif /* _PATH_OLDLOG */
if (xo_status == NOCONN) {
(void) close(xo_logfile);
xo_logfile = -1;
}
}
}
static void
xo_open_log_unlocked (const char *ident, int logstat, int logfac)
{
if (ident != NULL)
xo_logtag = ident;
xo_logstat = logstat;
if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0)
xo_logfacility = logfac;
if (xo_logstat & LOG_NDELAY) /* open immediately */
xo_connect_log();
xo_opened = 1; /* ident and facility has been set */
}
void
xo_open_log (const char *ident, int logstat, int logfac)
{
THREAD_LOCK();
xo_open_log_unlocked(ident, logstat, logfac);
THREAD_UNLOCK();
}
void
xo_close_log (void)
{
THREAD_LOCK();
if (xo_logfile != -1) {
(void) close(xo_logfile);
xo_logfile = -1;
}
xo_logtag = NULL;
xo_status = NOCONN;
THREAD_UNLOCK();
}
/* xo_set_logmask -- set the log mask level */
int
xo_set_logmask (int pmask)
{
int omask;
THREAD_LOCK();
omask = xo_logmask;
if (pmask != 0)
xo_logmask = pmask;
THREAD_UNLOCK();
return (omask);
}
void
xo_set_syslog_handler (xo_syslog_open_t open_func,
xo_syslog_send_t send_func,
xo_syslog_close_t close_func)
{
xo_syslog_open = open_func;
xo_syslog_send = send_func;
xo_syslog_close = close_func;
}
static size_t
xo_snprintf (char *out, size_t outsize, const char *fmt, ...)
{
int status;
size_t retval = 0;
va_list ap;
if (out && outsize) {
va_start(ap, fmt);
status = vsnprintf(out, outsize, fmt, ap);
if (status < 0) { /* this should never happen, */
*out = 0; /* handle it in the safest way possible if it does */
retval = 0;
} else {
retval = status;
retval = retval > outsize ? outsize : retval;
}
va_end(ap);
}
return retval;
}
static int
xo_syslog_handle_write (void *opaque, const char *data)
{
xo_buffer_t *xbp = opaque;
int len = strlen(data);
int left = xo_buf_left(xbp);
if (len > left - 1)
len = left - 1;
memcpy(xbp->xb_curp, data, len);
xbp->xb_curp += len;
*xbp->xb_curp = '\0';
return len;
}
static void
xo_syslog_handle_close (void *opaque UNUSED)
{
}
static int
xo_syslog_handle_flush (void *opaque UNUSED)
{
return 0;
}
void
xo_set_unit_test_mode (int value)
{
xo_unit_test = value;
}
void
xo_vsyslog (int pri, const char *name, const char *fmt, va_list vap)
{
int saved_errno = errno;
char tbuf[2048];
char *tp = NULL, *ep = NULL;
unsigned start_of_msg = 0;
char *v0_hdr = NULL;
xo_buffer_t xb;
static pid_t my_pid;
unsigned log_offset;
if (my_pid == 0)
my_pid = xo_unit_test ? 222 : getpid();
/* Check for invalid bits */
if (pri & ~(LOG_PRIMASK|LOG_FACMASK)) {
xo_syslog(LOG_ERR | LOG_CONS | LOG_PERROR | LOG_PID,
"syslog-unknown-priority",
"syslog: unknown facility/priority: %#x", pri);
pri &= LOG_PRIMASK|LOG_FACMASK;
}
THREAD_LOCK();
/* Check priority against setlogmask values. */
if (!(LOG_MASK(LOG_PRI(pri)) & xo_logmask)) {
THREAD_UNLOCK();
return;
}
/* Set default facility if none specified. */
if ((pri & LOG_FACMASK) == 0)
pri |= xo_logfacility;
/* Create the primary stdio hook */
xb.xb_bufp = tbuf;
xb.xb_curp = tbuf;
xb.xb_size = sizeof(tbuf);
xo_handle_t *xop = xo_create(XO_STYLE_SDPARAMS, 0);
if (xop == NULL) {
THREAD_UNLOCK();
return;
}
#ifdef HAVE_GETPROGNAME
if (xo_logtag == NULL)
xo_logtag = getprogname();
#endif /* HAVE_GETPROGNAME */
xo_set_writer(xop, &xb, xo_syslog_handle_write, xo_syslog_handle_close,
xo_syslog_handle_flush);
/* Build the message; start by getting the time */
struct tm tm;
struct timeval tv;
/* Unit test hack: fake a fixed time */
if (xo_unit_test) {
tv.tv_sec = 1435085229;
tv.tv_usec = 123456;
} else
gettimeofday(&tv, NULL);
(void) localtime_r(&tv.tv_sec, &tm);
if (xo_logstat & LOG_PERROR) {
/*
* For backwards compatibility, we need to make the old-style
* message. This message can be emitted to the console/tty.
*/
v0_hdr = alloca(2048);
tp = v0_hdr;
ep = v0_hdr + 2048;
if (xo_logtag != NULL)
tp += xo_snprintf(tp, ep - tp, "%s", xo_logtag);
if (xo_logstat & LOG_PID)
tp += xo_snprintf(tp, ep - tp, "[%d]", my_pid);
if (xo_logtag)
tp += xo_snprintf(tp, ep - tp, ": ");
}
log_offset = xb.xb_curp - xb.xb_bufp;
/* Add PRI, PRIVAL, and VERSION */
xb.xb_curp += xo_snprintf(xb.xb_curp, xo_buf_left(&xb), "<%d>1 ", pri);
/* Add TIMESTAMP with milliseconds and TZOFFSET */
xb.xb_curp += strftime(xb.xb_curp, xo_buf_left(&xb), "%FT%T", &tm);
xb.xb_curp += xo_snprintf(xb.xb_curp, xo_buf_left(&xb),
".%03.3u", tv.tv_usec / 1000);
xb.xb_curp += strftime(xb.xb_curp, xo_buf_left(&xb), "%z ", &tm);
/*
* Add HOSTNAME; we rely on gethostname and don't fluff with
* ip addresses. Might need to revisit.....
*/
char hostname[HOST_NAME_MAX];
hostname[0] = '\0';
if (xo_unit_test)
strcpy(hostname, "worker-host");
else
(void) gethostname(hostname, sizeof(hostname));
xb.xb_curp += xo_snprintf(xb.xb_curp, xo_buf_left(&xb), "%s ",
hostname[0] ? hostname : "-");
/* Add APP-NAME */
xb.xb_curp += xo_snprintf(xb.xb_curp, xo_buf_left(&xb), "%s ",
xo_logtag ?: "-");
/* Add PROCID */
xb.xb_curp += xo_snprintf(xb.xb_curp, xo_buf_left(&xb), "%d ", my_pid);
/*
* Add MSGID. The user should provide us with a name, which we
* prefix with the current enterprise ID, as learned from the kernel.
* If the kernel won't tell us, we use the stock/builtin number.
*/
char *buf UNUSED = NULL;
const char *eid = xo_syslog_enterprise_id;
const char *at_sign = "@";
if (name == NULL) {
name = "-";
eid = at_sign = "";
} else if (*name == '@') {
/* Our convention is to prefix IANA-defined names with an "@" */
name += 1;
eid = at_sign = "";
} else if (eid[0] == '\0') {
#ifdef HAVE_SYSCTLBYNAME
/*
* See if the kernel knows the sysctl for the enterprise ID
*/
size_t size = 0;
if (sysctlbyname(XO_SYSLOG_ENTERPRISE_ID, NULL, &size, NULL, 0) == 0
&& size > 0) {
buf = alloca(size);
if (sysctlbyname(XO_SYSLOG_ENTERPRISE_ID, buf, &size, NULL, 0) == 0
&& size > 0)
eid = buf;
}
#endif /* HAVE_SYSCTLBYNAME */
if (eid[0] == '\0') {
/* Fallback to our base default */
xo_set_syslog_enterprise_id(XO_DEFAULT_EID);
eid = xo_syslog_enterprise_id;
}
}
xb.xb_curp += xo_snprintf(xb.xb_curp, xo_buf_left(&xb), "%s [%s%s%s ",
name, name, at_sign, eid);
/*
* Now for the real content. We make two distinct passes thru the
* xo_emit engine, first for the SD-PARAMS and then for the text
* message.
*/
va_list ap;
va_copy(ap, vap);
errno = saved_errno; /* Restore saved error value */
xo_emit_hv(xop, fmt, ap);
xo_flush_h(xop);
va_end(ap);
/* Trim trailing space */
if (xb.xb_curp[-1] == ' ')
xb.xb_curp -= 1;
/* Close the structured data (SD-ELEMENT) */
xb.xb_curp += xo_snprintf(xb.xb_curp, xo_buf_left(&xb), "] ");
/*
* Since our MSG is known to be UTF-8, we MUST prefix it with
* that most-annoying-of-all-UTF-8 features, the BOM (0xEF.BB.BF).
*/
xb.xb_curp += xo_snprintf(xb.xb_curp, xo_buf_left(&xb),
"%c%c%c", 0xEF, 0xBB, 0xBF);
/* Save the start of the message */
if (xo_logstat & LOG_PERROR)
start_of_msg = xb.xb_curp - xb.xb_bufp;
xo_set_style(xop, XO_STYLE_TEXT);
xo_set_flags(xop, XOF_UTF8);
errno = saved_errno; /* Restore saved error value */
xo_emit_hv(xop, fmt, ap);
xo_flush_h(xop);
/* Remove a trailing newline */
if (xb.xb_curp[-1] == '\n')
*--xb.xb_curp = '\0';
if (xo_get_flags(xop) & XOF_LOG_SYSLOG)
fprintf(stderr, "xo: syslog: %s\n", xb.xb_bufp + log_offset);
xo_send_syslog(xb.xb_bufp, v0_hdr, xb.xb_bufp + start_of_msg);
xo_destroy(xop);
THREAD_UNLOCK();
}
/*
* syslog - print message on log file; output is intended for syslogd(8).
*/
void
xo_syslog (int pri, const char *name, const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
xo_vsyslog(pri, name, fmt, ap);
va_end(ap);
}
Reference in New Issue View Git Blame Copy Permalink