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-rw-r--r--crypto/openssh/log.c657
1 files changed, 657 insertions, 0 deletions
diff --git a/crypto/openssh/log.c b/crypto/openssh/log.c
new file mode 100644
index 000000000000..6617f26726bc
--- /dev/null
+++ b/crypto/openssh/log.c
@@ -0,0 +1,657 @@
+/* $OpenBSD: log.c,v 1.64 2024/12/07 10:05:36 djm Exp $ */
+/*
+ * Author: Tatu Ylonen <ylo@cs.hut.fi>
+ * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
+ * All rights reserved
+ *
+ * As far as I am concerned, the code I have written for this software
+ * can be used freely for any purpose. Any derived versions of this
+ * software must be clearly marked as such, and if the derived work is
+ * incompatible with the protocol description in the RFC file, it must be
+ * called by a name other than "ssh" or "Secure Shell".
+ */
+/*
+ * Copyright (c) 2000 Markus Friedl. 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 "includes.h"
+
+#include <sys/types.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syslog.h>
+#include <time.h>
+#include <unistd.h>
+#if defined(HAVE_STRNVIS) && defined(HAVE_VIS_H) && !defined(BROKEN_STRNVIS)
+# include <vis.h>
+#endif
+
+#include "log.h"
+#include "match.h"
+
+static LogLevel log_level = SYSLOG_LEVEL_INFO;
+static int log_on_stderr = 1;
+static int log_stderr_fd = STDERR_FILENO;
+static int log_facility = LOG_AUTH;
+static const char *argv0;
+static log_handler_fn *log_handler;
+static void *log_handler_ctx;
+static char **log_verbose;
+static size_t nlog_verbose;
+
+extern char *__progname;
+
+#define LOG_SYSLOG_VIS (VIS_CSTYLE|VIS_NL|VIS_TAB|VIS_OCTAL)
+#define LOG_STDERR_VIS (VIS_SAFE|VIS_OCTAL)
+
+/* textual representation of log-facilities/levels */
+
+static struct {
+ const char *name;
+ SyslogFacility val;
+} log_facilities[] = {
+ { "DAEMON", SYSLOG_FACILITY_DAEMON },
+ { "USER", SYSLOG_FACILITY_USER },
+ { "AUTH", SYSLOG_FACILITY_AUTH },
+#ifdef LOG_AUTHPRIV
+ { "AUTHPRIV", SYSLOG_FACILITY_AUTHPRIV },
+#endif
+ { "LOCAL0", SYSLOG_FACILITY_LOCAL0 },
+ { "LOCAL1", SYSLOG_FACILITY_LOCAL1 },
+ { "LOCAL2", SYSLOG_FACILITY_LOCAL2 },
+ { "LOCAL3", SYSLOG_FACILITY_LOCAL3 },
+ { "LOCAL4", SYSLOG_FACILITY_LOCAL4 },
+ { "LOCAL5", SYSLOG_FACILITY_LOCAL5 },
+ { "LOCAL6", SYSLOG_FACILITY_LOCAL6 },
+ { "LOCAL7", SYSLOG_FACILITY_LOCAL7 },
+ { NULL, SYSLOG_FACILITY_NOT_SET }
+};
+
+static struct {
+ const char *name;
+ LogLevel val;
+} log_levels[] =
+{
+ { "QUIET", SYSLOG_LEVEL_QUIET },
+ { "FATAL", SYSLOG_LEVEL_FATAL },
+ { "ERROR", SYSLOG_LEVEL_ERROR },
+ { "INFO", SYSLOG_LEVEL_INFO },
+ { "VERBOSE", SYSLOG_LEVEL_VERBOSE },
+ { "DEBUG", SYSLOG_LEVEL_DEBUG1 },
+ { "DEBUG1", SYSLOG_LEVEL_DEBUG1 },
+ { "DEBUG2", SYSLOG_LEVEL_DEBUG2 },
+ { "DEBUG3", SYSLOG_LEVEL_DEBUG3 },
+ { NULL, SYSLOG_LEVEL_NOT_SET }
+};
+
+LogLevel
+log_level_get(void)
+{
+ return log_level;
+}
+
+SyslogFacility
+log_facility_number(char *name)
+{
+ int i;
+
+ if (name != NULL)
+ for (i = 0; log_facilities[i].name; i++)
+ if (strcasecmp(log_facilities[i].name, name) == 0)
+ return log_facilities[i].val;
+ return SYSLOG_FACILITY_NOT_SET;
+}
+
+const char *
+log_facility_name(SyslogFacility facility)
+{
+ u_int i;
+
+ for (i = 0; log_facilities[i].name; i++)
+ if (log_facilities[i].val == facility)
+ return log_facilities[i].name;
+ return NULL;
+}
+
+LogLevel
+log_level_number(char *name)
+{
+ int i;
+
+ if (name != NULL)
+ for (i = 0; log_levels[i].name; i++)
+ if (strcasecmp(log_levels[i].name, name) == 0)
+ return log_levels[i].val;
+ return SYSLOG_LEVEL_NOT_SET;
+}
+
+const char *
+log_level_name(LogLevel level)
+{
+ u_int i;
+
+ for (i = 0; log_levels[i].name != NULL; i++)
+ if (log_levels[i].val == level)
+ return log_levels[i].name;
+ return NULL;
+}
+
+void
+log_verbose_add(const char *s)
+{
+ char **tmp;
+
+ /* Ignore failures here */
+ if ((tmp = recallocarray(log_verbose, nlog_verbose, nlog_verbose + 1,
+ sizeof(*log_verbose))) != NULL) {
+ log_verbose = tmp;
+ if ((log_verbose[nlog_verbose] = strdup(s)) != NULL)
+ nlog_verbose++;
+ }
+}
+
+void
+log_verbose_reset(void)
+{
+ size_t i;
+
+ for (i = 0; i < nlog_verbose; i++)
+ free(log_verbose[i]);
+ free(log_verbose);
+ log_verbose = NULL;
+ nlog_verbose = 0;
+}
+
+/*
+ * Initialize the log.
+ */
+
+void
+log_init(const char *av0, LogLevel level, SyslogFacility facility,
+ int on_stderr)
+{
+#if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
+ struct syslog_data sdata = SYSLOG_DATA_INIT;
+#endif
+
+ argv0 = av0;
+
+ if (log_change_level(level) != 0) {
+ fprintf(stderr, "Unrecognized internal syslog level code %d\n",
+ (int) level);
+ exit(1);
+ }
+
+ log_handler = NULL;
+ log_handler_ctx = NULL;
+
+ log_on_stderr = on_stderr;
+ if (on_stderr)
+ return;
+
+ switch (facility) {
+ case SYSLOG_FACILITY_DAEMON:
+ log_facility = LOG_DAEMON;
+ break;
+ case SYSLOG_FACILITY_USER:
+ log_facility = LOG_USER;
+ break;
+ case SYSLOG_FACILITY_AUTH:
+ log_facility = LOG_AUTH;
+ break;
+#ifdef LOG_AUTHPRIV
+ case SYSLOG_FACILITY_AUTHPRIV:
+ log_facility = LOG_AUTHPRIV;
+ break;
+#endif
+ case SYSLOG_FACILITY_LOCAL0:
+ log_facility = LOG_LOCAL0;
+ break;
+ case SYSLOG_FACILITY_LOCAL1:
+ log_facility = LOG_LOCAL1;
+ break;
+ case SYSLOG_FACILITY_LOCAL2:
+ log_facility = LOG_LOCAL2;
+ break;
+ case SYSLOG_FACILITY_LOCAL3:
+ log_facility = LOG_LOCAL3;
+ break;
+ case SYSLOG_FACILITY_LOCAL4:
+ log_facility = LOG_LOCAL4;
+ break;
+ case SYSLOG_FACILITY_LOCAL5:
+ log_facility = LOG_LOCAL5;
+ break;
+ case SYSLOG_FACILITY_LOCAL6:
+ log_facility = LOG_LOCAL6;
+ break;
+ case SYSLOG_FACILITY_LOCAL7:
+ log_facility = LOG_LOCAL7;
+ break;
+ default:
+ fprintf(stderr,
+ "Unrecognized internal syslog facility code %d\n",
+ (int) facility);
+ exit(1);
+ }
+
+ /*
+ * If an external library (eg libwrap) attempts to use syslog
+ * immediately after reexec, syslog may be pointing to the wrong
+ * facility, so we force an open/close of syslog here.
+ */
+#if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
+ openlog_r(argv0 ? argv0 : __progname, LOG_PID, log_facility, &sdata);
+ closelog_r(&sdata);
+#else
+ openlog(argv0 ? argv0 : __progname, LOG_PID, log_facility);
+ closelog();
+#endif
+}
+
+int
+log_change_level(LogLevel new_log_level)
+{
+ /* no-op if log_init has not been called */
+ if (argv0 == NULL)
+ return 0;
+
+ switch (new_log_level) {
+ case SYSLOG_LEVEL_QUIET:
+ case SYSLOG_LEVEL_FATAL:
+ case SYSLOG_LEVEL_ERROR:
+ case SYSLOG_LEVEL_INFO:
+ case SYSLOG_LEVEL_VERBOSE:
+ case SYSLOG_LEVEL_DEBUG1:
+ case SYSLOG_LEVEL_DEBUG2:
+ case SYSLOG_LEVEL_DEBUG3:
+ log_level = new_log_level;
+ return 0;
+ default:
+ return -1;
+ }
+}
+
+int
+log_is_on_stderr(void)
+{
+ return log_on_stderr && log_stderr_fd == STDERR_FILENO;
+}
+
+/* redirect what would usually get written to stderr to specified file */
+void
+log_redirect_stderr_to(const char *logfile)
+{
+ int fd;
+
+ if (logfile == NULL) {
+ if (log_stderr_fd != STDERR_FILENO) {
+ close(log_stderr_fd);
+ log_stderr_fd = STDERR_FILENO;
+ }
+ return;
+ }
+
+ if ((fd = open(logfile, O_WRONLY|O_CREAT|O_APPEND, 0600)) == -1) {
+ fprintf(stderr, "Couldn't open logfile %s: %s\n", logfile,
+ strerror(errno));
+ exit(1);
+ }
+ log_stderr_fd = fd;
+}
+
+#define MSGBUFSIZ 1024
+
+void
+set_log_handler(log_handler_fn *handler, void *ctx)
+{
+ log_handler = handler;
+ log_handler_ctx = ctx;
+}
+
+static void
+do_log(LogLevel level, int force, const char *suffix, const char *fmt,
+ va_list args)
+{
+#if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
+ struct syslog_data sdata = SYSLOG_DATA_INIT;
+#endif
+ char msgbuf[MSGBUFSIZ];
+ char fmtbuf[MSGBUFSIZ];
+ char *txt = NULL;
+ int pri = LOG_INFO;
+ int saved_errno = errno;
+ log_handler_fn *tmp_handler;
+ const char *progname = argv0 != NULL ? argv0 : __progname;
+
+ if (!force && level > log_level)
+ return;
+
+ switch (level) {
+ case SYSLOG_LEVEL_FATAL:
+ if (!log_on_stderr)
+ txt = "fatal";
+ pri = LOG_CRIT;
+ break;
+ case SYSLOG_LEVEL_ERROR:
+ if (!log_on_stderr)
+ txt = "error";
+ pri = LOG_ERR;
+ break;
+ case SYSLOG_LEVEL_INFO:
+ pri = LOG_INFO;
+ break;
+ case SYSLOG_LEVEL_VERBOSE:
+ pri = LOG_INFO;
+ break;
+ case SYSLOG_LEVEL_DEBUG1:
+ txt = "debug1";
+ pri = LOG_DEBUG;
+ break;
+ case SYSLOG_LEVEL_DEBUG2:
+ txt = "debug2";
+ pri = LOG_DEBUG;
+ break;
+ case SYSLOG_LEVEL_DEBUG3:
+ txt = "debug3";
+ pri = LOG_DEBUG;
+ break;
+ default:
+ txt = "internal error";
+ pri = LOG_ERR;
+ break;
+ }
+ if (txt != NULL && log_handler == NULL) {
+ snprintf(fmtbuf, sizeof(fmtbuf), "%s: %s", txt, fmt);
+ vsnprintf(msgbuf, sizeof(msgbuf), fmtbuf, args);
+ } else {
+ vsnprintf(msgbuf, sizeof(msgbuf), fmt, args);
+ }
+ if (suffix != NULL) {
+ snprintf(fmtbuf, sizeof(fmtbuf), "%s: %s", msgbuf, suffix);
+ strlcpy(msgbuf, fmtbuf, sizeof(msgbuf));
+ }
+ strnvis(fmtbuf, msgbuf, sizeof(fmtbuf),
+ log_on_stderr ? LOG_STDERR_VIS : LOG_SYSLOG_VIS);
+ if (log_handler != NULL) {
+ /* Avoid recursion */
+ tmp_handler = log_handler;
+ log_handler = NULL;
+ tmp_handler(level, force, fmtbuf, log_handler_ctx);
+ log_handler = tmp_handler;
+ } else if (log_on_stderr) {
+ snprintf(msgbuf, sizeof msgbuf, "%s%s%.*s\r\n",
+ (log_on_stderr > 1) ? progname : "",
+ (log_on_stderr > 1) ? ": " : "",
+ (int)sizeof msgbuf - 3, fmtbuf);
+ (void)write(log_stderr_fd, msgbuf, strlen(msgbuf));
+ } else {
+#if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
+ openlog_r(progname, LOG_PID, log_facility, &sdata);
+ syslog_r(pri, &sdata, "%.500s", fmtbuf);
+ closelog_r(&sdata);
+#else
+ openlog(progname, LOG_PID, log_facility);
+ syslog(pri, "%.500s", fmtbuf);
+ closelog();
+#endif
+ }
+ errno = saved_errno;
+}
+
+void
+sshlog(const char *file, const char *func, int line, int showfunc,
+ LogLevel level, const char *suffix, const char *fmt, ...)
+{
+ va_list args;
+
+ va_start(args, fmt);
+ sshlogv(file, func, line, showfunc, level, suffix, fmt, args);
+ va_end(args);
+}
+
+void
+sshlogdie(const char *file, const char *func, int line, int showfunc,
+ LogLevel level, const char *suffix, const char *fmt, ...)
+{
+ va_list args;
+
+ va_start(args, fmt);
+ sshlogv(file, func, line, showfunc, SYSLOG_LEVEL_INFO,
+ suffix, fmt, args);
+ va_end(args);
+ cleanup_exit(255);
+}
+
+void
+sshlogv(const char *file, const char *func, int line, int showfunc,
+ LogLevel level, const char *suffix, const char *fmt, va_list args)
+{
+ char tag[128], fmt2[MSGBUFSIZ + 128];
+ int forced = 0;
+ const char *cp;
+ size_t i;
+
+ /* short circuit processing early if we're not going to log anything */
+ if (nlog_verbose == 0 && level > log_level)
+ return;
+
+ snprintf(tag, sizeof(tag), "%.48s:%.48s():%d (bin=%s, pid=%ld)",
+ (cp = strrchr(file, '/')) == NULL ? file : cp + 1, func, line,
+ argv0 == NULL ? "UNKNOWN" : argv0, (long)getpid());
+ for (i = 0; i < nlog_verbose; i++) {
+ if (match_pattern_list(tag, log_verbose[i], 0) == 1) {
+ forced = 1;
+ break;
+ }
+ }
+
+ if (forced)
+ snprintf(fmt2, sizeof(fmt2), "%s: %s", tag, fmt);
+ else if (showfunc)
+ snprintf(fmt2, sizeof(fmt2), "%s: %s", func, fmt);
+ else
+ strlcpy(fmt2, fmt, sizeof(fmt2));
+
+ do_log(level, forced, suffix, fmt2, args);
+}
+
+void
+sshlogdirect(LogLevel level, int forced, const char *fmt, ...)
+{
+ va_list args;
+
+ va_start(args, fmt);
+ do_log(level, forced, NULL, fmt, args);
+ va_end(args);
+}
+
+
+/*
+ * A simple system for ratelimiting aperiodic events such as logs, without
+ * needing to be hooked into a mainloop/timer. A running total of events is
+ * maintained and when it exceeds a threshold further events are dropped
+ * until the rate falls back below that threshold.
+ *
+ * To prevent flipping in and out of rate-limiting, there is a hysteresis
+ * timer that delays leaving the rate-limited state.
+ *
+ * While in the rate-limited state, events can be periodically allowed though
+ * and the number of dropped events since the last log obtained.
+ *
+ * XXX a moving average rate of events might be a better approach here rather
+ * than linear decay, which can suppress events for a while after large
+ * bursts.
+ */
+
+/* #define RATELIMIT_DEBUG 1 */
+
+#ifdef RATELIMIT_DEBUG
+# define RLDBG(x) do { \
+ printf("%s:%d %s: ", __FILE__, __LINE__, __func__); \
+ printf x; \
+ printf("\n"); \
+ fflush(stdout); \
+ } while (0)
+#else
+# define RLDBG(x)
+#endif
+
+/* set up a ratelimit */
+void
+log_ratelimit_init(struct log_ratelimit_ctx *rl, u_int threshold,
+ u_int max_accum, u_int hysteresis, u_int log_every)
+{
+ memset(rl, 0, sizeof(*rl));
+ rl->threshold = threshold;
+ rl->max_accum = max_accum;
+ rl->hysteresis = hysteresis;
+ rl->log_every = log_every;
+ RLDBG(("called: rl=%p thresh=%u max=%u hys=%u log_every=%u",
+ rl, rl->threshold, rl->max_accum, rl->hysteresis, rl->log_every));
+}
+
+/*
+ * check whether a log event should be dropped because of rate-limiting.
+ * returns non-zero if the event should be dropped. If events_since_last
+ * is supplied then, for periodic logs, it will be set to the number of
+ * dropped events since the last message.
+ */
+int
+log_ratelimit(struct log_ratelimit_ctx *rl, time_t now, int *active,
+ u_int *events_dropped)
+{
+ time_t olast_event;
+
+ RLDBG(("called: rl=%p thresh=%u max=%u hys=%u log_every=%u "
+ "accum=%u since=%ld since_last=%u", rl, rl->threshold,
+ rl->max_accum, rl->hysteresis,
+ rl->log_every, rl->accumulated_events,
+ rl->last_event == 0 ? -1 : (long)(now - rl->last_event),
+ rl->ratelimited_events));
+
+ if (now < 0)
+ return 0;
+ if (events_dropped != NULL)
+ *events_dropped = 0;
+ if (active != NULL)
+ *active = rl->ratelimit_active;
+
+ /* First, decay accumulated events */
+ if (rl->last_event <= 0)
+ rl->last_event = now;
+ if (now > rl->last_event) {
+ uint64_t n = now - rl->last_event;
+
+ if (n > UINT_MAX)
+ n = UINT_MAX;
+ if (rl->accumulated_events < (u_int)n)
+ rl->accumulated_events = 0;
+ else
+ rl->accumulated_events -= (u_int)n;
+ RLDBG(("decay: accum=%u", rl->accumulated_events));
+ }
+ rl->accumulated_events++; /* add this event */
+ if (rl->accumulated_events > rl->max_accum)
+ rl->accumulated_events = rl->max_accum;
+ olast_event = rl->last_event;
+ rl->last_event = now;
+ RLDBG(("check threshold: accum=%u vs thresh=%u",
+ rl->accumulated_events, rl->threshold));
+
+ /* Are we under threshold? */
+ if (rl->accumulated_events < rl->threshold) {
+ if (!rl->ratelimit_active)
+ return 0;
+ RLDBG(("under threshold: hys=%u since_hys=%ld since_last=%ld",
+ rl->hysteresis, rl->hysteresis_start == 0 ? -1 :
+ (long)(now - rl->hysteresis_start),
+ olast_event == 0 ? -1 : (long)(now - olast_event)));
+ if (rl->hysteresis_start == 0) {
+ /* active, but under threshold; hysteresis */
+ if (olast_event + rl->hysteresis < now) {
+ /* hysteresis expired before this event */
+ RLDBG(("hysteresis preexpired"));
+ goto inactive;
+ }
+ RLDBG(("start hysteresis"));
+ rl->hysteresis_start = now;
+ } else if (rl->hysteresis_start + rl->hysteresis < now) {
+ /* Hysteresis period expired, transition to inactive */
+ RLDBG(("complete hysteresis"));
+ inactive:
+ if (events_dropped != NULL)
+ *events_dropped = rl->ratelimited_events;
+ if (active != NULL)
+ *active = 0;
+ rl->ratelimit_active = 0;
+ rl->ratelimit_start = 0;
+ rl->last_log = 0;
+ rl->hysteresis_start = 0;
+ rl->ratelimited_events = 0;
+ return 0;
+ }
+ /* ratelimiting active, but in hysteresis period */
+ } else if (!rl->ratelimit_active) {
+ /* Transition to rate-limiting */
+ RLDBG(("start ratelimit"));
+ rl->ratelimit_active = 1;
+ rl->ratelimit_start = now;
+ rl->last_log = now;
+ rl->hysteresis_start = 0;
+ rl->ratelimited_events = 1;
+ if (active != NULL)
+ *active = 1;
+ return 1;
+ } else if (rl->hysteresis_start != 0) {
+ /* active and over threshold; reset hysteresis timer */
+ RLDBG(("clear hysteresis"));
+ rl->hysteresis_start = 0;
+ }
+
+ /* over threshold or in hysteresis period; log periodically */
+ if (active != NULL)
+ *active = 1;
+ RLDBG(("log_every=%u since_log=%ld", rl->log_every,
+ (long)(now - rl->last_log)));
+ if (rl->log_every > 0 && now >= rl->last_log + rl->log_every) {
+ RLDBG(("periodic: since_last=%u", rl->ratelimited_events));
+ rl->last_log = now;
+ if (events_dropped != NULL) {
+ *events_dropped = rl->ratelimited_events;
+ rl->ratelimited_events = 0;
+ }
+ return 0;
+ }
+
+ /* drop event */
+ rl->ratelimited_events++;
+ RLDBG(("drop: ratelimited_events=%u", rl->ratelimited_events));
+ return 1;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2025-11-07 16:47:03 +0000