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Diffstat (limited to 'log.c')
-rw-r--r--log.c258
1 files changed, 240 insertions, 18 deletions
diff --git a/log.c b/log.c
index 54a7cbb..d769a33 100644
--- a/log.c
+++ b/log.c
@@ -12,7 +12,12 @@
* Author: Stefano Brivio <sbrivio@redhat.com>
*/
+#include <arpa/inet.h>
+#include <limits.h>
+#include <errno.h>
+#include <fcntl.h>
#include <stdio.h>
+#include <stdint.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
@@ -20,36 +25,49 @@
#include <syslog.h>
#include <stdarg.h>
#include <sys/socket.h>
-#include <sys/un.h>
#include "log.h"
+#include "util.h"
+#include "passt.h"
-/* For __openlog() and __setlogmask() wrappers, and passt_vsyslog() */
-static int log_mask;
-static int log_sock = -1;
-static char log_ident[BUFSIZ];
-static int log_opt;
-static time_t log_debug_start;
-int log_trace;
+static int log_sock = -1; /* Optional socket to system logger */
+static char log_ident[BUFSIZ]; /* Identifier string for openlog() */
+static int log_mask; /* Current log priority mask */
+static int log_opt; /* Options for openlog() */
+
+static int log_file = -1; /* Optional log file descriptor */
+static size_t log_size; /* Maximum log file size in bytes */
+static size_t log_written; /* Currently used bytes in log file */
+static size_t log_cut_size; /* Bytes to cut at start on rotation */
+static char log_header[BUFSIZ]; /* File header, written back on cuts */
+
+static time_t log_start; /* Start timestamp */
+int log_trace; /* --trace mode enabled */
#define logfn(name, level) \
void name(const char *format, ...) { \
struct timespec tp; \
va_list args; \
\
- if (setlogmask(0) & LOG_MASK(LOG_DEBUG)) { \
+ if (setlogmask(0) & LOG_MASK(LOG_DEBUG) && log_file == -1) { \
clock_gettime(CLOCK_REALTIME, &tp); \
fprintf(stderr, "%li.%04li: ", \
- tp.tv_sec - log_debug_start, \
+ tp.tv_sec - log_start, \
tp.tv_nsec / (100L * 1000)); \
- } else { \
+ } \
+ \
+ if ((LOG_MASK(LOG_PRI(level)) & log_mask) || \
+ setlogmask(0) == LOG_MASK(LOG_EMERG)) { \
va_start(args, format); \
- passt_vsyslog(level, format, args); \
+ if (log_file != -1) \
+ logfile_write(level, format, args); \
+ else if (!(setlogmask(0) & LOG_MASK(LOG_DEBUG))) \
+ passt_vsyslog(level, format, args); \
va_end(args); \
} \
\
- if (setlogmask(0) & LOG_MASK(LOG_DEBUG) || \
- setlogmask(0) == LOG_MASK(LOG_EMERG)) { \
+ if ((setlogmask(0) & LOG_MASK(LOG_DEBUG) || \
+ setlogmask(0) == LOG_MASK(LOG_EMERG)) && log_file == -1) { \
va_start(args, format); \
(void)vfprintf(stderr, format, args); \
va_end(args); \
@@ -58,6 +76,16 @@ void name(const char *format, ...) { \
} \
}
+/* Prefixes for log file messages, indexed by priority */
+const char *logfile_prefix[] = {
+ NULL, NULL, NULL, /* Unused: LOG_EMERG, LOG_ALERT, LOG_CRIT */
+ "ERROR: ",
+ "WARNING: ",
+ NULL, /* Unused: LOG_NOTICE */
+ "info: ",
+ " ", /* LOG_DEBUG */
+};
+
logfn(err, LOG_ERR)
logfn(warn, LOG_WARNING)
logfn(info, LOG_INFO)
@@ -79,7 +107,7 @@ void __openlog(const char *ident, int option, int facility)
struct timespec tp;
clock_gettime(CLOCK_REALTIME, &tp);
- log_debug_start = tp.tv_sec;
+ log_start = tp.tv_sec;
if (log_sock < 0) {
struct sockaddr_un a = { .sun_family = AF_UNIX, };
@@ -124,9 +152,6 @@ void passt_vsyslog(int pri, const char *format, va_list ap)
char buf[BUFSIZ];
int n;
- if (!(LOG_MASK(LOG_PRI(pri)) & log_mask))
- return;
-
/* Send without name and timestamp, the system logger should add them */
n = snprintf(buf, BUFSIZ, "<%i> ", pri);
@@ -141,3 +166,200 @@ void passt_vsyslog(int pri, const char *format, va_list ap)
if (send(log_sock, buf, n, 0) != n)
fprintf(stderr, "Failed to send %i bytes to syslog\n", n);
}
+
+/**
+ * logfile_init() - Open log file and write header with PID and path
+ * @name: Identifier for header: passt or pasta
+ * @path: Path to log file
+ * @size: Maximum size of log file: log_cut_size is calculatd here
+ */
+void logfile_init(const char *name, const char *path, size_t size)
+{
+ char nl = '\n', exe[PATH_MAX] = { 0 };
+ int n;
+
+ if (readlink("/proc/self/exe", exe, PATH_MAX - 1) < 0) {
+ perror("readlink /proc/self/exe");
+ exit(EXIT_FAILURE);
+ }
+
+ log_file = open(path, O_CREAT | O_TRUNC | O_APPEND | O_RDWR | O_CLOEXEC,
+ S_IRUSR | S_IWUSR);
+ if (log_file == -1) {
+ err("Couldn't open log file %s: %s", path, strerror(errno));
+ exit(EXIT_FAILURE);
+ }
+
+ log_size = size ? size : LOGFILE_SIZE_DEFAULT;
+
+ n = snprintf(log_header, sizeof(log_header), "%s: %s (%i)",
+ name, exe, getpid());
+
+ if (write(log_file, log_header, n) <= 0 ||
+ write(log_file, &nl, 1) <= 0) {
+ perror("Couldn't write to log file\n");
+ exit(EXIT_FAILURE);
+ }
+
+ /* For FALLOC_FL_COLLAPSE_RANGE: VFS block size can be up to one page */
+ log_cut_size = ROUND_UP(log_size * LOGFILE_CUT_RATIO / 100, PAGE_SIZE);
+}
+
+#ifdef FALLOC_FL_COLLAPSE_RANGE
+/**
+ * logfile_rotate_fallocate() - Write header, set log_written after fallocate()
+ * @fd: Log file descriptor
+ * @ts: Current timestamp
+ *
+ * #syscalls lseek ppc64le:_llseek ppc64:_llseek armv6l:_llseek armv7l:_llseek
+ */
+static void logfile_rotate_fallocate(int fd, struct timespec *ts)
+{
+ char buf[BUFSIZ], *nl;
+ int n;
+
+ if (lseek(fd, 0, SEEK_SET) == -1)
+ return;
+ if (read(fd, buf, BUFSIZ) == -1)
+ return;
+
+ n = snprintf(buf, BUFSIZ,
+ "%s - log truncated at %li.%04li", log_header,
+ ts->tv_sec - log_start, ts->tv_nsec / (100L * 1000));
+
+ /* Avoid partial lines by padding the header with spaces */
+ nl = memchr(buf + n + 1, '\n', BUFSIZ - n - 1);
+ if (nl)
+ memset(buf + n, ' ', nl - (buf + n));
+
+ if (lseek(fd, 0, SEEK_SET) == -1)
+ return;
+ if (write(fd, buf, BUFSIZ) == -1)
+ return;
+
+ log_written -= log_cut_size;
+}
+#endif /* FALLOC_FL_COLLAPSE_RANGE */
+
+/**
+ * logfile_rotate_move() - Fallback: move recent entries toward start, then cut
+ * @fd: Log file descriptor
+ * @ts: Current timestamp
+ *
+ * #syscalls lseek ppc64le:_llseek ppc64:_llseek armv6l:_llseek armv7l:_llseek
+ * #syscalls ftruncate
+ */
+static void logfile_rotate_move(int fd, struct timespec *ts)
+{
+ int header_len, write_offset, end, discard, n;
+ char buf[BUFSIZ], *nl;
+
+ header_len = snprintf(buf, BUFSIZ,
+ "%s - log truncated at %li.%04li\n", log_header,
+ ts->tv_sec - log_start,
+ ts->tv_nsec / (100L * 1000));
+ if (lseek(fd, 0, SEEK_SET) == -1)
+ return;
+ if (write(fd, buf, header_len) == -1)
+ return;
+
+ end = write_offset = header_len;
+ discard = log_cut_size + header_len;
+
+ /* Try to cut cleanly at newline */
+ if (lseek(fd, discard, SEEK_SET) == -1)
+ goto out;
+ if ((n = read(fd, buf, BUFSIZ)) <= 0)
+ goto out;
+ if ((nl = memchr(buf, '\n', n)))
+ discard += (nl - buf) + 1;
+
+ /* Go to first block to be moved */
+ if (lseek(fd, discard, SEEK_SET) == -1)
+ goto out;
+
+ while ((n = read(fd, buf, BUFSIZ)) > 0) {
+ end = header_len;
+
+ if (lseek(fd, write_offset, SEEK_SET) == -1)
+ goto out;
+ if ((n = write(fd, buf, n)) == -1)
+ goto out;
+ write_offset += n;
+
+ if ((n = lseek(fd, 0, SEEK_CUR)) == -1)
+ goto out;
+
+ if (lseek(fd, discard - header_len, SEEK_CUR) == -1)
+ goto out;
+
+ end = n;
+ }
+
+out:
+ if (ftruncate(fd, end))
+ return;
+
+ log_written = end;
+}
+
+/**
+ * logfile_rotate() - "Rotate" log file once it's full
+ * @fd: Log file descriptor
+ * @ts: Current timestamp
+ *
+ * Return: 0 on success, negative error code on failure
+ *
+ * #syscalls fcntl
+ *
+ * fallocate() passed as EXTRA_SYSCALL only if FALLOC_FL_COLLAPSE_RANGE is there
+ */
+static int logfile_rotate(int fd, struct timespec *ts)
+{
+ if (fcntl(fd, F_SETFL, O_RDWR /* Drop O_APPEND: explicit lseek() */))
+ return -errno;
+
+#ifdef FALLOC_FL_COLLAPSE_RANGE
+ /* Only for Linux >= 3.15, extent-based ext4 or XFS, glibc >= 2.18 */
+ if (!fallocate(fd, FALLOC_FL_COLLAPSE_RANGE, 0, log_cut_size))
+ logfile_rotate_fallocate(fd, ts);
+ else
+#endif
+ logfile_rotate_move(fd, ts);
+
+ if (fcntl(fd, F_SETFL, O_RDWR | O_APPEND))
+ return -errno;
+
+ return 0;
+}
+
+/**
+ * logfile_write() - Write entry to log file, trigger rotation if full
+ * @pri: Facility and level map, same as priority for vsyslog()
+ * @format: Same as vsyslog() format
+ * @ap: Same as vsyslog() ap
+ */
+void logfile_write(int pri, const char *format, va_list ap)
+{
+ struct timespec ts;
+ char buf[BUFSIZ];
+ int n;
+
+ if (clock_gettime(CLOCK_REALTIME, &ts))
+ return;
+
+ n = snprintf(buf, BUFSIZ, "%li.%04li: %s",
+ ts.tv_sec - log_start, ts.tv_nsec / (100L * 1000),
+ logfile_prefix[pri]);
+
+ n += vsnprintf(buf + n, BUFSIZ - n, format, ap);
+
+ if (format[strlen(format)] != '\n')
+ n += snprintf(buf + n, BUFSIZ - n, "\n");
+
+ if ((log_written + n >= log_size) && logfile_rotate(log_file, &ts))
+ return;
+
+ if ((n = write(log_file, buf, n)) >= 0)
+ log_written += n;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-03 22:04:31 +0000