diff options
Diffstat (limited to 'log.c')
| -rw-r--r-- | log.c | 258 |
1 files changed, 240 insertions, 18 deletions
@@ -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; +} |