| /* SPDX-License-Identifier: LGPL-2.1+ */ |
| /*** |
| This file is part of systemd. |
| |
| Copyright 2011 Lennart Poettering |
| |
| systemd is free software; you can redistribute it and/or modify it |
| under the terms of the GNU Lesser General Public License as published by |
| the Free Software Foundation; either version 2.1 of the License, or |
| (at your option) any later version. |
| |
| systemd is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public License |
| along with systemd; If not, see <http://www.gnu.org/licenses/>. |
| ***/ |
| |
| #include <fcntl.h> |
| #include <sys/epoll.h> |
| #include <sys/mman.h> |
| #include <sys/socket.h> |
| #include <unistd.h> |
| |
| #include "libudev.h" |
| #include "sd-messages.h" |
| |
| #include "alloc-util.h" |
| #include "escape.h" |
| #include "fd-util.h" |
| #include "format-util.h" |
| #include "io-util.h" |
| #include "journald-kmsg.h" |
| #include "journald-server.h" |
| #include "journald-syslog.h" |
| #include "parse-util.h" |
| #include "process-util.h" |
| #include "stdio-util.h" |
| #include "string-util.h" |
| |
| void server_forward_kmsg( |
| Server *s, |
| int priority, |
| const char *identifier, |
| const char *message, |
| const struct ucred *ucred) { |
| |
| _cleanup_free_ char *ident_buf = NULL; |
| struct iovec iovec[5]; |
| char header_priority[DECIMAL_STR_MAX(priority) + 3], |
| header_pid[STRLEN("[]: ") + DECIMAL_STR_MAX(pid_t) + 1]; |
| int n = 0; |
| |
| assert(s); |
| assert(priority >= 0); |
| assert(priority <= 999); |
| assert(message); |
| |
| if (_unlikely_(LOG_PRI(priority) > s->max_level_kmsg)) |
| return; |
| |
| if (_unlikely_(s->dev_kmsg_fd < 0)) |
| return; |
| |
| /* Never allow messages with kernel facility to be written to |
| * kmsg, regardless where the data comes from. */ |
| priority = syslog_fixup_facility(priority); |
| |
| /* First: priority field */ |
| xsprintf(header_priority, "<%i>", priority); |
| iovec[n++] = IOVEC_MAKE_STRING(header_priority); |
| |
| /* Second: identifier and PID */ |
| if (ucred) { |
| if (!identifier) { |
| get_process_comm(ucred->pid, &ident_buf); |
| identifier = ident_buf; |
| } |
| |
| xsprintf(header_pid, "["PID_FMT"]: ", ucred->pid); |
| |
| if (identifier) |
| iovec[n++] = IOVEC_MAKE_STRING(identifier); |
| |
| iovec[n++] = IOVEC_MAKE_STRING(header_pid); |
| } else if (identifier) { |
| iovec[n++] = IOVEC_MAKE_STRING(identifier); |
| iovec[n++] = IOVEC_MAKE_STRING(": "); |
| } |
| |
| /* Fourth: message */ |
| iovec[n++] = IOVEC_MAKE_STRING(message); |
| iovec[n++] = IOVEC_MAKE_STRING("\n"); |
| |
| if (writev(s->dev_kmsg_fd, iovec, n) < 0) |
| log_debug_errno(errno, "Failed to write to /dev/kmsg for logging: %m"); |
| } |
| |
| static bool is_us(const char *pid) { |
| pid_t t; |
| |
| assert(pid); |
| |
| if (parse_pid(pid, &t) < 0) |
| return false; |
| |
| return t == getpid_cached(); |
| } |
| |
| static void dev_kmsg_record(Server *s, const char *p, size_t l) { |
| |
| _cleanup_free_ char *message = NULL, *syslog_priority = NULL, *syslog_pid = NULL, *syslog_facility = NULL, *syslog_identifier = NULL, *source_time = NULL, *identifier = NULL, *pid = NULL; |
| struct iovec iovec[N_IOVEC_META_FIELDS + 7 + N_IOVEC_KERNEL_FIELDS + 2 + N_IOVEC_UDEV_FIELDS]; |
| char *kernel_device = NULL; |
| unsigned long long usec; |
| size_t n = 0, z = 0, j; |
| int priority, r; |
| char *e, *f, *k; |
| uint64_t serial; |
| size_t pl; |
| |
| assert(s); |
| assert(p); |
| |
| if (l <= 0) |
| return; |
| |
| e = memchr(p, ',', l); |
| if (!e) |
| return; |
| *e = 0; |
| |
| r = safe_atoi(p, &priority); |
| if (r < 0 || priority < 0 || priority > 999) |
| return; |
| |
| if (s->forward_to_kmsg && (priority & LOG_FACMASK) != LOG_KERN) |
| return; |
| |
| l -= (e - p) + 1; |
| p = e + 1; |
| e = memchr(p, ',', l); |
| if (!e) |
| return; |
| *e = 0; |
| |
| r = safe_atou64(p, &serial); |
| if (r < 0) |
| return; |
| |
| if (s->kernel_seqnum) { |
| /* We already read this one? */ |
| if (serial < *s->kernel_seqnum) |
| return; |
| |
| /* Did we lose any? */ |
| if (serial > *s->kernel_seqnum) |
| server_driver_message(s, 0, |
| "MESSAGE_ID=" SD_MESSAGE_JOURNAL_MISSED_STR, |
| LOG_MESSAGE("Missed %"PRIu64" kernel messages", |
| serial - *s->kernel_seqnum), |
| NULL); |
| |
| /* Make sure we never read this one again. Note that |
| * we always store the next message serial we expect |
| * here, simply because this makes handling the first |
| * message with serial 0 easy. */ |
| *s->kernel_seqnum = serial + 1; |
| } |
| |
| l -= (e - p) + 1; |
| p = e + 1; |
| f = memchr(p, ';', l); |
| if (!f) |
| return; |
| /* Kernel 3.6 has the flags field, kernel 3.5 lacks that */ |
| e = memchr(p, ',', l); |
| if (!e || f < e) |
| e = f; |
| *e = 0; |
| |
| r = safe_atollu(p, &usec); |
| if (r < 0) |
| return; |
| |
| l -= (f - p) + 1; |
| p = f + 1; |
| e = memchr(p, '\n', l); |
| if (!e) |
| return; |
| *e = 0; |
| |
| pl = e - p; |
| l -= (e - p) + 1; |
| k = e + 1; |
| |
| for (j = 0; l > 0 && j < N_IOVEC_KERNEL_FIELDS; j++) { |
| char *m; |
| /* Metadata fields attached */ |
| |
| if (*k != ' ') |
| break; |
| |
| k++, l--; |
| |
| e = memchr(k, '\n', l); |
| if (!e) |
| return; |
| |
| *e = 0; |
| |
| if (cunescape_length_with_prefix(k, e - k, "_KERNEL_", UNESCAPE_RELAX, &m) < 0) |
| break; |
| |
| if (startswith(m, "_KERNEL_DEVICE=")) |
| kernel_device = m + 15; |
| |
| iovec[n++] = IOVEC_MAKE_STRING(m); |
| z++; |
| |
| l -= (e - k) + 1; |
| k = e + 1; |
| } |
| |
| if (kernel_device) { |
| struct udev_device *ud; |
| |
| ud = udev_device_new_from_device_id(s->udev, kernel_device); |
| if (ud) { |
| const char *g; |
| struct udev_list_entry *ll; |
| char *b; |
| |
| g = udev_device_get_devnode(ud); |
| if (g) { |
| b = strappend("_UDEV_DEVNODE=", g); |
| if (b) { |
| iovec[n++] = IOVEC_MAKE_STRING(b); |
| z++; |
| } |
| } |
| |
| g = udev_device_get_sysname(ud); |
| if (g) { |
| b = strappend("_UDEV_SYSNAME=", g); |
| if (b) { |
| iovec[n++] = IOVEC_MAKE_STRING(b); |
| z++; |
| } |
| } |
| |
| j = 0; |
| ll = udev_device_get_devlinks_list_entry(ud); |
| udev_list_entry_foreach(ll, ll) { |
| |
| if (j > N_IOVEC_UDEV_FIELDS) |
| break; |
| |
| g = udev_list_entry_get_name(ll); |
| if (g) { |
| b = strappend("_UDEV_DEVLINK=", g); |
| if (b) { |
| iovec[n++] = IOVEC_MAKE_STRING(b); |
| z++; |
| } |
| } |
| |
| j++; |
| } |
| |
| udev_device_unref(ud); |
| } |
| } |
| |
| if (asprintf(&source_time, "_SOURCE_MONOTONIC_TIMESTAMP=%llu", usec) >= 0) |
| iovec[n++] = IOVEC_MAKE_STRING(source_time); |
| |
| iovec[n++] = IOVEC_MAKE_STRING("_TRANSPORT=kernel"); |
| |
| if (asprintf(&syslog_priority, "PRIORITY=%i", priority & LOG_PRIMASK) >= 0) |
| iovec[n++] = IOVEC_MAKE_STRING(syslog_priority); |
| |
| if (asprintf(&syslog_facility, "SYSLOG_FACILITY=%i", LOG_FAC(priority)) >= 0) |
| iovec[n++] = IOVEC_MAKE_STRING(syslog_facility); |
| |
| if ((priority & LOG_FACMASK) == LOG_KERN) |
| iovec[n++] = IOVEC_MAKE_STRING("SYSLOG_IDENTIFIER=kernel"); |
| else { |
| pl -= syslog_parse_identifier((const char**) &p, &identifier, &pid); |
| |
| /* Avoid any messages we generated ourselves via |
| * log_info() and friends. */ |
| if (pid && is_us(pid)) |
| goto finish; |
| |
| if (identifier) { |
| syslog_identifier = strappend("SYSLOG_IDENTIFIER=", identifier); |
| if (syslog_identifier) |
| iovec[n++] = IOVEC_MAKE_STRING(syslog_identifier); |
| } |
| |
| if (pid) { |
| syslog_pid = strappend("SYSLOG_PID=", pid); |
| if (syslog_pid) |
| iovec[n++] = IOVEC_MAKE_STRING(syslog_pid); |
| } |
| } |
| |
| if (cunescape_length_with_prefix(p, pl, "MESSAGE=", UNESCAPE_RELAX, &message) >= 0) |
| iovec[n++] = IOVEC_MAKE_STRING(message); |
| |
| server_dispatch_message(s, iovec, n, ELEMENTSOF(iovec), NULL, NULL, priority, 0); |
| |
| finish: |
| for (j = 0; j < z; j++) |
| free(iovec[j].iov_base); |
| } |
| |
| static int server_read_dev_kmsg(Server *s) { |
| char buffer[8192+1]; /* the kernel-side limit per record is 8K currently */ |
| ssize_t l; |
| |
| assert(s); |
| assert(s->dev_kmsg_fd >= 0); |
| |
| l = read(s->dev_kmsg_fd, buffer, sizeof(buffer) - 1); |
| if (l == 0) |
| return 0; |
| if (l < 0) { |
| /* Old kernels who don't allow reading from /dev/kmsg |
| * return EINVAL when we try. So handle this cleanly, |
| * but don' try to ever read from it again. */ |
| if (errno == EINVAL) { |
| s->dev_kmsg_event_source = sd_event_source_unref(s->dev_kmsg_event_source); |
| return 0; |
| } |
| |
| if (IN_SET(errno, EAGAIN, EINTR, EPIPE)) |
| return 0; |
| |
| return log_error_errno(errno, "Failed to read from kernel: %m"); |
| } |
| |
| dev_kmsg_record(s, buffer, l); |
| return 1; |
| } |
| |
| int server_flush_dev_kmsg(Server *s) { |
| int r; |
| |
| assert(s); |
| |
| if (s->dev_kmsg_fd < 0) |
| return 0; |
| |
| if (!s->dev_kmsg_readable) |
| return 0; |
| |
| log_debug("Flushing /dev/kmsg..."); |
| |
| for (;;) { |
| r = server_read_dev_kmsg(s); |
| if (r < 0) |
| return r; |
| |
| if (r == 0) |
| break; |
| } |
| |
| return 0; |
| } |
| |
| static int dispatch_dev_kmsg(sd_event_source *es, int fd, uint32_t revents, void *userdata) { |
| Server *s = userdata; |
| |
| assert(es); |
| assert(fd == s->dev_kmsg_fd); |
| assert(s); |
| |
| if (revents & EPOLLERR) |
| log_warning("/dev/kmsg buffer overrun, some messages lost."); |
| |
| if (!(revents & EPOLLIN)) |
| log_error("Got invalid event from epoll for /dev/kmsg: %"PRIx32, revents); |
| |
| return server_read_dev_kmsg(s); |
| } |
| |
| int server_open_dev_kmsg(Server *s) { |
| mode_t mode; |
| int r; |
| |
| assert(s); |
| |
| if (s->read_kmsg) |
| mode = O_RDWR|O_CLOEXEC|O_NONBLOCK|O_NOCTTY; |
| else |
| mode = O_WRONLY|O_CLOEXEC|O_NONBLOCK|O_NOCTTY; |
| |
| s->dev_kmsg_fd = open("/dev/kmsg", mode); |
| if (s->dev_kmsg_fd < 0) { |
| log_full(errno == ENOENT ? LOG_DEBUG : LOG_WARNING, |
| "Failed to open /dev/kmsg, ignoring: %m"); |
| return 0; |
| } |
| |
| if (!s->read_kmsg) |
| return 0; |
| |
| r = sd_event_add_io(s->event, &s->dev_kmsg_event_source, s->dev_kmsg_fd, EPOLLIN, dispatch_dev_kmsg, s); |
| if (r < 0) { |
| |
| /* This will fail with EPERM on older kernels where |
| * /dev/kmsg is not readable. */ |
| if (r == -EPERM) { |
| r = 0; |
| goto fail; |
| } |
| |
| log_error_errno(r, "Failed to add /dev/kmsg fd to event loop: %m"); |
| goto fail; |
| } |
| |
| r = sd_event_source_set_priority(s->dev_kmsg_event_source, SD_EVENT_PRIORITY_IMPORTANT+10); |
| if (r < 0) { |
| log_error_errno(r, "Failed to adjust priority of kmsg event source: %m"); |
| goto fail; |
| } |
| |
| s->dev_kmsg_readable = true; |
| |
| return 0; |
| |
| fail: |
| s->dev_kmsg_event_source = sd_event_source_unref(s->dev_kmsg_event_source); |
| s->dev_kmsg_fd = safe_close(s->dev_kmsg_fd); |
| |
| return r; |
| } |
| |
| int server_open_kernel_seqnum(Server *s) { |
| _cleanup_close_ int fd; |
| uint64_t *p; |
| int r; |
| |
| assert(s); |
| |
| /* We store the seqnum we last read in an mmaped file. That |
| * way we can just use it like a variable, but it is |
| * persistent and automatically flushed at reboot. */ |
| |
| fd = open("/run/systemd/journal/kernel-seqnum", O_RDWR|O_CREAT|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, 0644); |
| if (fd < 0) { |
| log_error_errno(errno, "Failed to open /run/systemd/journal/kernel-seqnum, ignoring: %m"); |
| return 0; |
| } |
| |
| r = posix_fallocate(fd, 0, sizeof(uint64_t)); |
| if (r != 0) { |
| log_error_errno(r, "Failed to allocate sequential number file, ignoring: %m"); |
| return 0; |
| } |
| |
| p = mmap(NULL, sizeof(uint64_t), PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); |
| if (p == MAP_FAILED) { |
| log_error_errno(errno, "Failed to map sequential number file, ignoring: %m"); |
| return 0; |
| } |
| |
| s->kernel_seqnum = p; |
| |
| return 0; |
| } |