diff options
Diffstat (limited to 'lib/zlog_targets.c')
-rw-r--r-- | lib/zlog_targets.c | 577 |
1 files changed, 577 insertions, 0 deletions
diff --git a/lib/zlog_targets.c b/lib/zlog_targets.c new file mode 100644 index 0000000..b0f7571 --- /dev/null +++ b/lib/zlog_targets.c @@ -0,0 +1,577 @@ +// SPDX-License-Identifier: ISC +/* + * Copyright (c) 2015-19 David Lamparter, for NetDEF, Inc. + */ + +#include "zebra.h" + +#include <sys/un.h> +#include <syslog.h> + +#include "memory.h" +#include "frrcu.h" +#include "frr_pthread.h" +#include "printfrr.h" +#include "zlog.h" +#include "zlog_targets.h" + +/* these allocations are intentionally left active even when doing full exit + * cleanup, in order to keep the logging subsystem fully functional until the + * absolute end. + */ + +DEFINE_MGROUP_ACTIVEATEXIT(LOG, "logging subsystem"); + +DEFINE_MTYPE_STATIC(LOG, LOG_FD, "log file target"); +DEFINE_MTYPE_STATIC(LOG, LOG_FD_NAME, "log file name"); +DEFINE_MTYPE_STATIC(LOG, LOG_FD_ROTATE, "log file rotate helper"); +DEFINE_MTYPE_STATIC(LOG, LOG_SYSL, "syslog target"); + +struct zlt_fd { + struct zlog_target zt; + + atomic_uint_fast32_t fd; + + char ts_subsec; + bool record_priority; + + struct rcu_head_close head_close; +}; + +static const char * const prionames[] = { + [LOG_EMERG] = "emergencies: ", + [LOG_ALERT] = "alerts: ", + [LOG_CRIT] = "critical: ", + [LOG_ERR] = "errors: ", + [LOG_WARNING] = "warnings: ", + [LOG_NOTICE] = "notifications: ", + [LOG_INFO] = "informational: ", + [LOG_DEBUG] = "debugging: ", +}; + +void zlog_fd(struct zlog_target *zt, struct zlog_msg *msgs[], size_t nmsgs) +{ + struct zlt_fd *zte = container_of(zt, struct zlt_fd, zt); + int fd; + size_t i, textlen, iovpos = 0; + size_t niov = MIN(4 * nmsgs + 1, IOV_MAX); + struct iovec iov[niov]; + /* "\nYYYY-MM-DD HH:MM:SS.NNNNNNNNN+ZZ:ZZ " = 37 chars */ +#define TS_LEN 40 + char ts_buf[TS_LEN * nmsgs], *ts_pos = ts_buf; + + fd = atomic_load_explicit(&zte->fd, memory_order_relaxed); + + for (i = 0; i < nmsgs; i++) { + struct zlog_msg *msg = msgs[i]; + int prio = zlog_msg_prio(msg); + + if (prio <= zt->prio_min) { + struct fbuf fbuf = { + .buf = ts_buf, + .pos = ts_pos, + .len = sizeof(ts_buf), + }; + + iov[iovpos].iov_base = ts_pos; + zlog_msg_ts(msg, &fbuf, + ZLOG_TS_LEGACY | zte->ts_subsec); + ts_pos = fbuf.pos; + + *ts_pos++ = ' '; + iov[iovpos].iov_len = + ts_pos - (char *)iov[iovpos].iov_base; + + iovpos++; + + if (zte->record_priority) { + iov[iovpos].iov_base = (char *)prionames[prio]; + iov[iovpos].iov_len = + strlen(iov[iovpos].iov_base); + + iovpos++; + } + + iov[iovpos].iov_base = zlog_prefix; + iov[iovpos].iov_len = zlog_prefixsz; + + iovpos++; + + iov[iovpos].iov_base = + (char *)zlog_msg_text(msg, &textlen); + iov[iovpos].iov_len = textlen + 1; + + iovpos++; + } + + /* conditions that trigger writing: + * - out of space for more timestamps/headers + * - this being the last message in the batch + * - not enough remaining iov entries + */ + if (iovpos > 0 && (ts_buf + sizeof(ts_buf) - ts_pos < TS_LEN + || i + 1 == nmsgs + || array_size(iov) - iovpos < 5)) { + writev(fd, iov, iovpos); + + iovpos = 0; + ts_pos = ts_buf; + } + } + + assert(iovpos == 0); +} + +static void zlog_fd_sigsafe(struct zlog_target *zt, const char *text, + size_t len) +{ + struct zlt_fd *zte = container_of(zt, struct zlt_fd, zt); + struct iovec iov[4]; + int fd; + + iov[0].iov_base = (char *)prionames[LOG_CRIT]; + iov[0].iov_len = zte->record_priority ? strlen(iov[0].iov_base) : 0; + + iov[1].iov_base = zlog_prefix; + iov[1].iov_len = zlog_prefixsz; + + iov[2].iov_base = (char *)text; + iov[2].iov_len = len; + + iov[3].iov_base = (char *)"\n"; + iov[3].iov_len = 1; + + fd = atomic_load_explicit(&zte->fd, memory_order_relaxed); + + writev(fd, iov, array_size(iov)); +} + +/* + * (re-)configuration + */ + +void zlog_file_init(struct zlog_cfg_file *zcf) +{ + memset(zcf, 0, sizeof(*zcf)); + zcf->prio_min = ZLOG_DISABLED; + zcf->fd = -1; + pthread_mutex_init(&zcf->cfg_mtx, NULL); +} + +static void zlog_file_target_free(struct zlt_fd *zlt) +{ + if (!zlt) + return; + + rcu_close(&zlt->head_close, zlt->fd); + rcu_free(MTYPE_LOG_FD, zlt, zt.rcu_head); +} + +void zlog_file_fini(struct zlog_cfg_file *zcf) +{ + if (zcf->active) { + struct zlt_fd *ztf; + struct zlog_target *zt; + + zt = zlog_target_replace(&zcf->active->zt, NULL); + ztf = container_of(zt, struct zlt_fd, zt); + zlog_file_target_free(ztf); + } + XFREE(MTYPE_LOG_FD_NAME, zcf->filename); + pthread_mutex_destroy(&zcf->cfg_mtx); +} + +static bool zlog_file_cycle(struct zlog_cfg_file *zcf) +{ + struct zlog_target *zt, *old; + struct zlt_fd *zlt = NULL; + int fd; + bool rv = true; + + do { + if (zcf->prio_min == ZLOG_DISABLED) + break; + + if (zcf->fd != -1) + fd = dup(zcf->fd); + else if (zcf->filename) + fd = open(zcf->filename, + O_WRONLY | O_APPEND | O_CREAT | O_CLOEXEC + | O_NOCTTY, + LOGFILE_MASK); + else + fd = -1; + + if (fd < 0) { + rv = false; + break; + } + + zt = zlog_target_clone(MTYPE_LOG_FD, &zcf->active->zt, + sizeof(*zlt)); + zlt = container_of(zt, struct zlt_fd, zt); + + zlt->fd = fd; + zlt->record_priority = zcf->record_priority; + zlt->ts_subsec = zcf->ts_subsec; + + zlt->zt.prio_min = zcf->prio_min; + zlt->zt.logfn = zcf->zlog_wrap ? zcf->zlog_wrap : zlog_fd; + zlt->zt.logfn_sigsafe = zlog_fd_sigsafe; + } while (0); + + old = zlog_target_replace(zcf->active ? &zcf->active->zt : NULL, + zlt ? &zlt->zt : NULL); + zcf->active = zlt; + + zlog_file_target_free(container_of_null(old, struct zlt_fd, zt)); + + return rv; +} + +void zlog_file_set_other(struct zlog_cfg_file *zcf) +{ + frr_with_mutex (&zcf->cfg_mtx) { + zlog_file_cycle(zcf); + } +} + +bool zlog_file_set_filename(struct zlog_cfg_file *zcf, const char *filename) +{ + frr_with_mutex (&zcf->cfg_mtx) { + XFREE(MTYPE_LOG_FD_NAME, zcf->filename); + zcf->filename = XSTRDUP(MTYPE_LOG_FD_NAME, filename); + zcf->fd = -1; + + return zlog_file_cycle(zcf); + } + assert(0); + return false; +} + +bool zlog_file_set_fd(struct zlog_cfg_file *zcf, int fd) +{ + frr_with_mutex (&zcf->cfg_mtx) { + if (zcf->fd == fd) + return true; + + XFREE(MTYPE_LOG_FD_NAME, zcf->filename); + zcf->fd = fd; + + return zlog_file_cycle(zcf); + } + assert(0); + return false; +} + +struct rcu_close_rotate { + struct rcu_head_close head_close; + struct rcu_head head_self; +}; + +bool zlog_file_rotate(struct zlog_cfg_file *zcf) +{ + struct rcu_close_rotate *rcr; + int fd; + + frr_with_mutex (&zcf->cfg_mtx) { + if (!zcf->active || !zcf->filename) + return true; + + fd = open(zcf->filename, + O_WRONLY | O_APPEND | O_CREAT | O_CLOEXEC | O_NOCTTY, + LOGFILE_MASK); + if (fd < 0) + return false; + + fd = atomic_exchange_explicit(&zcf->active->fd, + (uint_fast32_t)fd, + memory_order_relaxed); + } + + rcr = XCALLOC(MTYPE_LOG_FD_ROTATE, sizeof(*rcr)); + rcu_close(&rcr->head_close, fd); + rcu_free(MTYPE_LOG_FD_ROTATE, rcr, head_self); + + return true; +} + +/* fixed crash logging */ + +static struct zlt_fd zlog_crashlog; + +static void zlog_crashlog_sigsafe(struct zlog_target *zt, const char *text, + size_t len) +{ + static int crashlog_fd = -1; + + if (crashlog_fd == -1) { +#ifdef HAVE_OPENAT + crashlog_fd = openat(zlog_tmpdirfd, "crashlog", + O_WRONLY | O_APPEND | O_CREAT, + LOGFILE_MASK); +#endif + if (crashlog_fd < 0) + crashlog_fd = -2; + } + + if (crashlog_fd == -2) + return; + + zlog_crashlog.fd = crashlog_fd; + zlog_fd_sigsafe(&zlog_crashlog.zt, text, len); +} + +/* this is used for assert failures (they don't need AS-Safe logging) */ +static void zlog_crashlog_plain(struct zlog_target *zt, struct zlog_msg *msgs[], + size_t nmsgs) +{ + size_t i, len; + const char *text; + + for (i = 0; i < nmsgs; i++) { + if (zlog_msg_prio(msgs[i]) > zt->prio_min) + continue; + + text = zlog_msg_text(msgs[i], &len); + zlog_crashlog_sigsafe(zt, text, len); + } +} + +static void zlog_crashlog_init(void) +{ + zlog_crashlog.zt.prio_min = LOG_CRIT; + zlog_crashlog.zt.logfn = zlog_crashlog_plain; + zlog_crashlog.zt.logfn_sigsafe = zlog_crashlog_sigsafe; + zlog_crashlog.fd = -1; + + zlog_target_replace(NULL, &zlog_crashlog.zt); +} + +/* fixed logging for test/auxiliary programs */ + +static struct zlt_fd zlog_aux_stdout; +static bool zlog_is_aux; + +static int zlt_aux_init(const char *prefix, int prio_min) +{ + zlog_is_aux = true; + + zlog_aux_stdout.zt.prio_min = prio_min; + zlog_aux_stdout.zt.logfn = zlog_fd; + zlog_aux_stdout.zt.logfn_sigsafe = zlog_fd_sigsafe; + zlog_aux_stdout.fd = STDOUT_FILENO; + + zlog_target_replace(NULL, &zlog_aux_stdout.zt); + zlog_startup_end(); + return 0; +} + +static int zlt_init(const char *progname, const char *protoname, + unsigned short instance, uid_t uid, gid_t gid) +{ + openlog(progname, LOG_CONS | LOG_NDELAY | LOG_PID, LOG_DAEMON); + return 0; +} + +static int zlt_fini(void) +{ + closelog(); + return 0; +} + +/* fixed startup logging to stderr */ + +static struct zlt_fd zlog_startup_stderr; + +__attribute__((_CONSTRUCTOR(450))) static void zlog_startup_init(void) +{ + zlog_startup_stderr.zt.prio_min = LOG_WARNING; + zlog_startup_stderr.zt.logfn = zlog_fd; + zlog_startup_stderr.zt.logfn_sigsafe = zlog_fd_sigsafe; + zlog_startup_stderr.fd = STDERR_FILENO; + + zlog_target_replace(NULL, &zlog_startup_stderr.zt); + + hook_register(zlog_aux_init, zlt_aux_init); + hook_register(zlog_init, zlt_init); + hook_register(zlog_fini, zlt_fini); +} + +void zlog_startup_end(void) +{ + static bool startup_ended = false; + + if (startup_ended) + return; + startup_ended = true; + + zlog_target_replace(&zlog_startup_stderr.zt, NULL); + + if (zlog_is_aux) + return; + + /* until here, crashlogs go to stderr */ + zlog_crashlog_init(); +} + +/* syslog */ + +struct zlt_syslog { + struct zlog_target zt; + + int syslog_facility; +}; + +static void zlog_syslog(struct zlog_target *zt, struct zlog_msg *msgs[], + size_t nmsgs) +{ + size_t i; + struct zlt_syslog *zte = container_of(zt, struct zlt_syslog, zt); + const char *text; + size_t text_len; + + for (i = 0; i < nmsgs; i++) { + if (zlog_msg_prio(msgs[i]) > zt->prio_min) + continue; + + text = zlog_msg_text(msgs[i], &text_len); + syslog(zlog_msg_prio(msgs[i]) | zte->syslog_facility, "%.*s", + (int)text_len, text); + } +} + +#ifndef _PATH_LOG +#define _PATH_LOG "/dev/log" +#endif + +static void zlog_syslog_sigsafe(struct zlog_target *zt, const char *text, + size_t len) +{ + static int syslog_fd = -1; + + char hdr[192]; + size_t hdrlen; + struct iovec iov[2]; + + if (syslog_fd == -1) { + syslog_fd = socket(AF_UNIX, SOCK_DGRAM, 0); + if (syslog_fd >= 0) { + struct sockaddr_un sa; + socklen_t salen = sizeof(sa); + + sa.sun_family = AF_UNIX; + strlcpy(sa.sun_path, _PATH_LOG, sizeof(sa.sun_path)); +#ifdef HAVE_STRUCT_SOCKADDR_UN_SUN_LEN + salen = sa.sun_len = SUN_LEN(&sa); +#endif + if (connect(syslog_fd, (struct sockaddr *)&sa, salen)) { + close(syslog_fd); + syslog_fd = -1; + } + } + + /* /dev/log could be a fifo instead of a socket */ + if (syslog_fd == -1) { + syslog_fd = open(_PATH_LOG, O_WRONLY | O_NOCTTY); + if (syslog_fd < 0) + /* give up ... */ + syslog_fd = -2; + } + } + + if (syslog_fd == -2) + return; + + /* note zlog_prefix includes trailing ": ", need to cut off 2 chars */ + hdrlen = snprintfrr(hdr, sizeof(hdr), "<%d>%.*s[%ld]: ", LOG_CRIT, + zlog_prefixsz > 2 ? (int)(zlog_prefixsz - 2) : 0, + zlog_prefix, (long)getpid()); + + iov[0].iov_base = hdr; + iov[0].iov_len = hdrlen; + + iov[1].iov_base = (char *)text; + iov[1].iov_len = len; + + writev(syslog_fd, iov, array_size(iov)); +} + + +static pthread_mutex_t syslog_cfg_mutex = PTHREAD_MUTEX_INITIALIZER; +static struct zlt_syslog *zlt_syslog; +static int syslog_facility = LOG_DAEMON; +static int syslog_prio_min = ZLOG_DISABLED; + +void zlog_syslog_set_facility(int facility) +{ + struct zlog_target *newztc; + struct zlt_syslog *newzt; + + frr_with_mutex (&syslog_cfg_mutex) { + if (facility == syslog_facility) + return; + syslog_facility = facility; + + if (syslog_prio_min == ZLOG_DISABLED) + return; + + newztc = zlog_target_clone(MTYPE_LOG_SYSL, &zlt_syslog->zt, + sizeof(*newzt)); + newzt = container_of(newztc, struct zlt_syslog, zt); + newzt->syslog_facility = syslog_facility; + + zlog_target_free(MTYPE_LOG_SYSL, + zlog_target_replace(&zlt_syslog->zt, + &newzt->zt)); + + zlt_syslog = newzt; + } +} + +int zlog_syslog_get_facility(void) +{ + frr_with_mutex (&syslog_cfg_mutex) { + return syslog_facility; + } + assert(0); + return 0; +} + +void zlog_syslog_set_prio_min(int prio_min) +{ + struct zlog_target *newztc; + struct zlt_syslog *newzt = NULL; + + frr_with_mutex (&syslog_cfg_mutex) { + if (prio_min == syslog_prio_min) + return; + syslog_prio_min = prio_min; + + if (syslog_prio_min != ZLOG_DISABLED) { + newztc = zlog_target_clone(MTYPE_LOG_SYSL, + &zlt_syslog->zt, + sizeof(*newzt)); + newzt = container_of(newztc, struct zlt_syslog, zt); + newzt->zt.prio_min = prio_min; + newzt->zt.logfn = zlog_syslog; + newzt->zt.logfn_sigsafe = zlog_syslog_sigsafe; + newzt->syslog_facility = syslog_facility; + } + + zlog_target_free(MTYPE_LOG_SYSL, + zlog_target_replace(&zlt_syslog->zt, + &newzt->zt)); + + zlt_syslog = newzt; + } +} + +int zlog_syslog_get_prio_min(void) +{ + frr_with_mutex (&syslog_cfg_mutex) { + return syslog_prio_min; + } + assert(0); + return 0; +} |