+/* Copyright (c) 2012 Apple Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+#include <dlfcn.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <mach/mach_time.h>
+#include <os/alloc_once_private.h>
+#include <os/trace.h>
+#include <_simple.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syslog.h>
+#include <sys/time.h>
+#include <unistd.h>
+
+// Move this to trace.h when it's removed from assumes.h
+typedef bool (*os_redirect_t)(const char *);
+
+struct os_trace_globals_s {
+ uint64_t start;
+ os_redirect_t redirect;
+ int logfd;
+ bool prepend_timestamp : 1;
+ bool errors_only : 1;
+};
+
+// If user picked a filename, use it and only it.
+// Otherwise, first try /var/tmp, then $TMPDIR, then give up.
+static inline
+int
+_os_trace_open_file(const char *suggestion)
+{
+ if (suggestion) {
+ return open(suggestion, O_WRONLY | O_APPEND | O_CREAT | O_NOFOLLOW |
+ O_EXCL | O_CLOEXEC, 0644);
+ }
+
+ int fd;
+ char filename[PATH_MAX];
+ char path[PATH_MAX];
+
+ snprintf(filename, sizeof(filename), "os_trace.%s.%d.log", getprogname(),
+ getpid());
+
+ strlcpy(path, "/var/tmp/", sizeof(path));
+ if (access(path, W_OK) == 0) {
+ strlcat(path, filename, sizeof(path));
+ fd = open(path, O_WRONLY | O_APPEND | O_CREAT | O_NOFOLLOW | O_EXCL |
+ O_CLOEXEC, 0644);
+ if (fd >= 0) {
+ return fd;
+ }
+ }
+
+ const char *tmpdir = getenv("TMPDIR");
+ if (tmpdir) {
+ strlcpy(path, tmpdir, sizeof(path));
+ if (access(path, W_OK) == 0) {
+ strlcat(path, filename, sizeof(path));
+ fd = open(path, O_WRONLY | O_APPEND | O_CREAT | O_NOFOLLOW |
+ O_EXCL | O_CLOEXEC, 0644);
+ if (fd >= 0) {
+ return fd;
+ }
+ }
+ }
+
+ return -1;
+}
+
+static
+void
+_os_trace_init(void *globals)
+{
+ struct os_trace_globals_s *g = globals;
+
+ g->errors_only = false;
+
+ g->redirect = dlsym(RTLD_MAIN_ONLY, "_os_trace_redirect_func");
+
+ // This is a bit of a hack. LIBDISPATCH_LOG is part of dispatch's API.
+ // But now all dispatch logging goes through os_trace. So we have to
+ // recognize this env var here in Libc.
+ // rdar://problem/11685359 tracks deprecating LIBDISPATCH_LOG from dispatch.
+ char *e = getenv("LIBDISPATCH_LOG");
+ if (!e) {
+ e = getenv("OS_TRACE");
+ }
+
+ // Default log destination
+ if (!e || strcmp(e, "YES") == 0) {
+#if DEBUG
+ e = "file";
+#else
+ e = "syslog";
+#endif
+ }
+
+ if (strcmp(e, "NO") == 0) {
+ g->logfd = -1;
+ g->errors_only = true;
+ } else if (strcmp(e, "syslog") == 0) {
+ g->logfd = -1;
+ } else if (strcmp(e, "stderr") == 0) {
+ g->logfd = STDERR_FILENO;
+ } else if (strcmp(e, "stdout") == 0) {
+ g->logfd = STDOUT_FILENO;
+ } else if (strcmp(e, "file") == 0) {
+ g->logfd = _os_trace_open_file(NULL);
+ if (g->logfd == -1) {
+ g->errors_only = true;
+ }
+ } else {
+ g->logfd = _os_trace_open_file(e);
+ if (g->logfd == -1) {
+ g->errors_only = true;
+ }
+ }
+
+ // From now on, g->logfd == -1 means syslog; anything >= 0 is the
+ // fd to use. Remember that file descriptor 0 is a perfectly valid
+ // value for open() to return if you closed (or never had) stdin.
+
+ // Timestamp every log message if logging directly to file and no
+ // redirector is set up.
+ if (g->logfd >= 0 && !g->redirect) {
+ g->prepend_timestamp = true;
+
+ struct timeval tv;
+ gettimeofday(&tv, NULL);
+
+ g->start = mach_absolute_time();
+
+ dprintf(g->logfd,
+ "=== os_trace log file opened for %s[%u] at %ld.%06u",
+ getprogname(), getpid(),
+ tv.tv_sec, tv.tv_usec);
+ if (g->prepend_timestamp) {
+ mach_timebase_info_data_t tbi;
+ if (mach_timebase_info(&tbi) == 0) {
+ dprintf(g->logfd, " [ns=ticks*%u/%u]",
+ tbi.numer, tbi.denom);
+ }
+ }
+ dprintf(g->logfd, " ===\n");
+ }
+}
+
+static inline __OS_CONST
+struct os_trace_globals_s *
+os_trace_globals(void)
+{
+ return (struct os_trace_globals_s *)
+ os_alloc_once(OS_ALLOC_ONCE_KEY_OS_TRACE,
+ sizeof(struct os_trace_globals_s),
+ _os_trace_init);
+}
+
+static __attribute__((always_inline))
+uint64_t
+_os_trace_ticks_since_start(void)
+{
+ return mach_absolute_time() - os_trace_globals()->start;
+}
+
+// False on error writing to file
+static inline
+bool
+_os_trace_write_fd(int level __attribute__((__unused__)),
+ char *str, int fd)
+{
+ size_t len = strlen(str);
+
+ str[len++] = '\n'; // overwrite null - don't use str*() anymore
+
+ ssize_t rc, wlen = 0;
+ do {
+ rc = write(fd, &str[wlen], len - wlen);
+ if (os_slowpath(rc == -1)) {
+ if(errno == EINTR) {
+ rc = 0;
+ } else {
+ return false;
+ }
+ }
+ wlen += rc;
+ } while (wlen < len);
+
+ return true;
+}
+
+static __attribute__((__noinline__))
+void
+_os_trace_write_error(void)
+{
+ char err_str[256];
+ const char *pfx = "os_trace() :";
+ size_t pfxlen = strlen(pfx);
+
+ strlcpy(err_str, pfx, sizeof(err_str));
+ strerror_r(errno, err_str+pfxlen, sizeof(err_str)-pfxlen);
+ _simple_asl_log(LOG_ERR, "com.apple.os_trace", err_str);
+}
+
+static inline
+void
+_os_trace_write(int level, char *str)
+{
+ int fd = os_trace_globals()->logfd;
+ os_redirect_t rdr = os_trace_globals()->redirect;
+ // true = redirect has fully handled, don't log
+ if (os_slowpath(rdr) && os_fastpath(rdr(str))) {
+ return;
+ }
+ if (os_slowpath(fd >= 0)) {
+ if (os_fastpath(_os_trace_write_fd(level, str, fd))) {
+ return;
+ } else {
+ _os_trace_write_error();
+ os_trace_globals()->logfd = -1;
+ // Don't return, fall out to syslog().
+ }
+ }
+ _simple_asl_log(level, "com.apple.os_trace", str);
+}
+
+static __attribute__((always_inline))
+void
+_os_tracev(int level, const char *msg, va_list ap)
+{
+ if (os_slowpath(os_trace_globals()->errors_only) && level > LOG_ERR) {
+ // more important = lower integer
+ return;
+ }
+ char *buf, *freebuf;
+ size_t len;
+
+ len = vasprintf(&buf, msg, ap);
+ if (!buf) {
+ return;
+ }
+ freebuf = buf;
+
+ // The os_trace macros prepend many spaces to the format string.
+ // Overwrite them with a timestamp, *or* skip them.
+ const size_t pfxlen = strlen(_OS_TRACE_PREFIX);
+ const size_t timelen = 16;
+ __OS_COMPILETIME_ASSERT__(pfxlen >= timelen);
+
+ if (os_fastpath(len > pfxlen)) {
+ if (os_slowpath(os_trace_globals()->prepend_timestamp)) {
+ char tmp = buf[timelen];
+ snprintf(buf, timelen + 1, "%16llu", _os_trace_ticks_since_start());
+ buf[timelen] = tmp; // snprintf's null
+ } else {
+ buf += pfxlen;
+ }
+ }
+
+ _os_trace_write(level, buf);
+ free(freebuf);
+}
+
+void
+_os_trace_error_str(char *msg)
+{
+ _os_trace_write(LOG_ERR, msg);
+}
+
+__OS_PRINTFLIKE(1, 2)
+void
+_os_trace(const char *msg, ...)
+{
+ va_list ap;
+ va_start(ap, msg);
+ _os_tracev(LOG_DEBUG, msg, ap);
+ va_end(ap);
+}
projects / apple / libc.git / blobdiff