Adding upstream version 241.upstream/241upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 450 insertions, 0 deletions

diff --git a/src/journal/journald-kmsg.c b/src/journal/journald-kmsg.c
new file mode 100644
index 0000000..ce82102
--- /dev/null
+++ b/src/journal/journald-kmsg.c
@@ -0,0 +1,450 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <fcntl.h>
+#include <sys/epoll.h>
+#include <sys/mman.h>
+#include <sys/socket.h>
+#include <unistd.h>
+
+#include "sd-device.h"
+#include "sd-messages.h"
+
+#include "alloc-util.h"
+#include "device-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 *identifier, const char *pid) {
+        pid_t pid_num;
+
+        if (!identifier || !pid)
+                return false;
+
+        if (parse_pid(pid, &pid_num) < 0)
+                return false;
+
+        return pid_num == getpid_cached() &&
+               streq(identifier, program_invocation_short_name);
+}
+
+void dev_kmsg_record(Server *s, 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 && LOG_FAC(priority) != 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)
+                        goto finish;
+
+                *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) {
+                _cleanup_(sd_device_unrefp) sd_device *d = NULL;
+
+                if (sd_device_new_from_device_id(&d, kernel_device) >= 0) {
+                        const char *g;
+                        char *b;
+
+                        if (sd_device_get_devname(d, &g) >= 0) {
+                                b = strappend("_UDEV_DEVNODE=", g);
+                                if (b) {
+                                        iovec[n++] = IOVEC_MAKE_STRING(b);
+                                        z++;
+                                }
+                        }
+
+                        if (sd_device_get_sysname(d, &g) >= 0) {
+                                b = strappend("_UDEV_SYSNAME=", g);
+                                if (b) {
+                                        iovec[n++] = IOVEC_MAKE_STRING(b);
+                                        z++;
+                                }
+                        }
+
+                        j = 0;
+                        FOREACH_DEVICE_DEVLINK(d, g) {
+
+                                if (j >= N_IOVEC_UDEV_FIELDS)
+                                        break;
+
+                                b = strappend("_UDEV_DEVLINK=", g);
+                                if (b) {
+                                        iovec[n++] = IOVEC_MAKE_STRING(b);
+                                        z++;
+                                }
+
+                                j++;
+                        }
+                }
+        }
+
+        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 (LOG_FAC(priority) == 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 (is_us(identifier, 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;
+}