Adding upstream version 255.4.upstream/255.4

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

1 files changed, 536 insertions, 0 deletions

diff --git a/src/journal/journald-native.c b/src/journal/journald-native.c
new file mode 100644
index 0000000..315ec0b
--- /dev/null
+++ b/src/journal/journald-native.c
@@ -0,0 +1,536 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <stddef.h>
+#include <sys/epoll.h>
+#include <sys/mman.h>
+#include <sys/statvfs.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "fs-util.h"
+#include "iovec-util.h"
+#include "journal-importer.h"
+#include "journal-internal.h"
+#include "journal-util.h"
+#include "journald-client.h"
+#include "journald-console.h"
+#include "journald-kmsg.h"
+#include "journald-native.h"
+#include "journald-server.h"
+#include "journald-syslog.h"
+#include "journald-wall.h"
+#include "memfd-util.h"
+#include "memory-util.h"
+#include "missing_fcntl.h"
+#include "parse-util.h"
+#include "path-util.h"
+#include "process-util.h"
+#include "selinux-util.h"
+#include "socket-util.h"
+#include "string-util.h"
+#include "strv.h"
+#include "unaligned.h"
+
+static bool allow_object_pid(const struct ucred *ucred) {
+        return ucred && ucred->uid == 0;
+}
+
+static void server_process_entry_meta(
+                const char *p, size_t l,
+                const struct ucred *ucred,
+                int *priority,
+                char **identifier,
+                char **message,
+                pid_t *object_pid) {
+
+        /* We need to determine the priority of this entry for the rate limiting logic */
+
+        if (l == 10 &&
+            startswith(p, "PRIORITY=") &&
+            p[9] >= '0' && p[9] <= '9')
+                *priority = (*priority & LOG_FACMASK) | (p[9] - '0');
+
+        else if (l == 17 &&
+                 startswith(p, "SYSLOG_FACILITY=") &&
+                 p[16] >= '0' && p[16] <= '9')
+                *priority = (*priority & LOG_PRIMASK) | ((p[16] - '0') << 3);
+
+        else if (l == 18 &&
+                 startswith(p, "SYSLOG_FACILITY=") &&
+                 p[16] >= '0' && p[16] <= '9' &&
+                 p[17] >= '0' && p[17] <= '9')
+                *priority = (*priority & LOG_PRIMASK) | (((p[16] - '0')*10 + (p[17] - '0')) << 3);
+
+        else if (l >= 19 &&
+                 startswith(p, "SYSLOG_IDENTIFIER=")) {
+                char *t;
+
+                t = memdup_suffix0(p + 18, l - 18);
+                if (t)
+                        free_and_replace(*identifier, t);
+
+        } else if (l >= 8 &&
+                   startswith(p, "MESSAGE=")) {
+                char *t;
+
+                t = memdup_suffix0(p + 8, l - 8);
+                if (t)
+                        free_and_replace(*message, t);
+
+        } else if (l > STRLEN("OBJECT_PID=") &&
+                   l < STRLEN("OBJECT_PID=")  + DECIMAL_STR_MAX(pid_t) &&
+                   startswith(p, "OBJECT_PID=") &&
+                   allow_object_pid(ucred)) {
+                char buf[DECIMAL_STR_MAX(pid_t)];
+                memcpy(buf, p + STRLEN("OBJECT_PID="),
+                       l - STRLEN("OBJECT_PID="));
+                buf[l-STRLEN("OBJECT_PID=")] = '\0';
+
+                (void) parse_pid(buf, object_pid);
+        }
+}
+
+static int server_process_entry(
+                Server *s,
+                const void *buffer, size_t *remaining,
+                ClientContext *context,
+                const struct ucred *ucred,
+                const struct timeval *tv,
+                const char *label, size_t label_len) {
+
+        /* Process a single entry from a native message. Returns 0 if nothing special happened and the message
+         * processing should continue, and a negative or positive value otherwise.
+         *
+         * Note that *remaining is altered on both success and failure. */
+
+        size_t n = 0, j, tn = SIZE_MAX, entry_size = 0;
+        char *identifier = NULL, *message = NULL;
+        struct iovec *iovec = NULL;
+        int priority = LOG_INFO;
+        pid_t object_pid = 0;
+        const char *p;
+        int r = 1;
+
+        p = buffer;
+
+        while (*remaining > 0) {
+                const char *e, *q;
+
+                e = memchr(p, '\n', *remaining);
+
+                if (!e) {
+                        /* Trailing noise, let's ignore it, and flush what we collected */
+                        log_debug("Received message with trailing noise, ignoring.");
+                        break; /* finish processing of the message */
+                }
+
+                if (e == p) {
+                        /* Entry separator */
+                        *remaining -= 1;
+                        break;
+                }
+
+                if (IN_SET(*p, '.', '#')) {
+                        /* Ignore control commands for now, and comments too. */
+                        *remaining -= (e - p) + 1;
+                        p = e + 1;
+                        continue;
+                }
+
+                /* A property follows */
+                if (n > ENTRY_FIELD_COUNT_MAX) {
+                        log_debug("Received an entry that has more than " STRINGIFY(ENTRY_FIELD_COUNT_MAX) " fields, ignoring entry.");
+                        goto finish;
+                }
+
+                /* n existing properties, 1 new, +1 for _TRANSPORT */
+                if (!GREEDY_REALLOC(iovec,
+                                    n + 2 +
+                                    N_IOVEC_META_FIELDS + N_IOVEC_OBJECT_FIELDS +
+                                    client_context_extra_fields_n_iovec(context))) {
+                        r = log_oom();
+                        goto finish;
+                }
+
+                q = memchr(p, '=', e - p);
+                if (q) {
+                        if (journal_field_valid(p, q - p, false)) {
+                                size_t l;
+
+                                l = e - p;
+                                if (l > DATA_SIZE_MAX) {
+                                        log_debug("Received text block of %zu bytes is too large, ignoring entry.", l);
+                                        goto finish;
+                                }
+
+                                if (entry_size + l + n + 1 > ENTRY_SIZE_MAX) { /* data + separators + trailer */
+                                        log_debug("Entry is too big (%zu bytes after processing %zu entries), ignoring entry.",
+                                                  entry_size + l, n + 1);
+                                        goto finish;
+                                }
+
+                                /* If the field name starts with an underscore, skip the variable, since that indicates
+                                 * a trusted field */
+                                iovec[n++] = IOVEC_MAKE((char*) p, l);
+                                entry_size += l;
+
+                                server_process_entry_meta(p, l, ucred,
+                                                          &priority,
+                                                          &identifier,
+                                                          &message,
+                                                          &object_pid);
+                        }
+
+                        *remaining -= (e - p) + 1;
+                        p = e + 1;
+                        continue;
+                } else {
+                        uint64_t l, total;
+                        char *k;
+
+                        if (*remaining < e - p + 1 + sizeof(uint64_t) + 1) {
+                                log_debug("Failed to parse message, ignoring.");
+                                break;
+                        }
+
+                        l = unaligned_read_le64(e + 1);
+                        if (l > DATA_SIZE_MAX) {
+                                log_debug("Received binary data block of %"PRIu64" bytes is too large, ignoring entry.", l);
+                                goto finish;
+                        }
+
+                        total = (e - p) + 1 + l;
+                        if (entry_size + total + n + 1 > ENTRY_SIZE_MAX) { /* data + separators + trailer */
+                                log_debug("Entry is too big (%"PRIu64"bytes after processing %zu fields), ignoring.",
+                                          entry_size + total, n + 1);
+                                goto finish;
+                        }
+
+                        if ((uint64_t) *remaining < e - p + 1 + sizeof(uint64_t) + l + 1 ||
+                            e[1+sizeof(uint64_t)+l] != '\n') {
+                                log_debug("Failed to parse message, ignoring.");
+                                break;
+                        }
+
+                        k = malloc(total);
+                        if (!k) {
+                                log_oom();
+                                break;
+                        }
+
+                        memcpy(k, p, e - p);
+                        k[e - p] = '=';
+                        memcpy(k + (e - p) + 1, e + 1 + sizeof(uint64_t), l);
+
+                        if (journal_field_valid(p, e - p, false)) {
+                                iovec[n] = IOVEC_MAKE(k, (e - p) + 1 + l);
+                                entry_size += iovec[n].iov_len;
+                                n++;
+
+                                server_process_entry_meta(k, (e - p) + 1 + l, ucred,
+                                                          &priority,
+                                                          &identifier,
+                                                          &message,
+                                                          &object_pid);
+                        } else
+                                free(k);
+
+                        *remaining -= (e - p) + 1 + sizeof(uint64_t) + l + 1;
+                        p = e + 1 + sizeof(uint64_t) + l + 1;
+                }
+        }
+
+        if (n <= 0)
+                goto finish;
+
+        tn = n++;
+        iovec[tn] = IOVEC_MAKE_STRING("_TRANSPORT=journal");
+        entry_size += STRLEN("_TRANSPORT=journal");
+
+        if (entry_size + n + 1 > ENTRY_SIZE_MAX) { /* data + separators + trailer */
+                log_debug("Entry is too big with %zu properties and %zu bytes, ignoring.", n, entry_size);
+                goto finish;
+        }
+
+        r = 0; /* Success, we read the message. */
+
+        if (!client_context_test_priority(context, priority))
+                goto finish;
+
+        if (message) {
+                /* Ensure message is not NULL, otherwise strlen(message) would crash. This check needs to
+                 * be here until server_process_entry() is able to process messages containing \0 characters,
+                 * as we would have access to the actual size of message. */
+                r = client_context_check_keep_log(context, message, strlen(message));
+                if (r <= 0)
+                        goto finish;
+
+                if (s->forward_to_syslog)
+                        server_forward_syslog(s, syslog_fixup_facility(priority), identifier, message, ucred, tv);
+
+                if (s->forward_to_kmsg)
+                        server_forward_kmsg(s, priority, identifier, message, ucred);
+
+                if (s->forward_to_console)
+                        server_forward_console(s, priority, identifier, message, ucred);
+
+                if (s->forward_to_wall)
+                        server_forward_wall(s, priority, identifier, message, ucred);
+        }
+
+        server_dispatch_message(s, iovec, n, MALLOC_ELEMENTSOF(iovec), context, tv, priority, object_pid);
+
+finish:
+        for (j = 0; j < n; j++)  {
+                if (j == tn)
+                        continue;
+
+                if (iovec[j].iov_base < buffer ||
+                    (const char*) iovec[j].iov_base >= p + *remaining)
+                        free(iovec[j].iov_base);
+        }
+
+        free(iovec);
+        free(identifier);
+        free(message);
+
+        return r;
+}
+
+void server_process_native_message(
+                Server *s,
+                const char *buffer, size_t buffer_size,
+                const struct ucred *ucred,
+                const struct timeval *tv,
+                const char *label, size_t label_len) {
+
+        size_t remaining = buffer_size;
+        ClientContext *context = NULL;
+        int r;
+
+        assert(s);
+        assert(buffer || buffer_size == 0);
+
+        if (ucred && pid_is_valid(ucred->pid)) {
+                r = client_context_get(s, ucred->pid, ucred, label, label_len, NULL, &context);
+                if (r < 0)
+                        log_ratelimit_warning_errno(r, JOURNAL_LOG_RATELIMIT,
+                                                    "Failed to retrieve credentials for PID " PID_FMT ", ignoring: %m",
+                                                    ucred->pid);
+        }
+
+        do {
+                r = server_process_entry(s,
+                                         (const uint8_t*) buffer + (buffer_size - remaining), &remaining,
+                                         context, ucred, tv, label, label_len);
+        } while (r == 0);
+}
+
+void server_process_native_file(
+                Server *s,
+                int fd,
+                const struct ucred *ucred,
+                const struct timeval *tv,
+                const char *label, size_t label_len) {
+
+        struct stat st;
+        bool sealed;
+        int r;
+
+        /* Data is in the passed fd, probably it didn't fit in a datagram. */
+
+        assert(s);
+        assert(fd >= 0);
+
+        if (fstat(fd, &st) < 0) {
+                log_ratelimit_error_errno(errno, JOURNAL_LOG_RATELIMIT, "Failed to stat passed file, ignoring: %m");
+                return;
+        }
+
+        r = stat_verify_regular(&st);
+        if (r < 0) {
+                log_ratelimit_error_errno(r, JOURNAL_LOG_RATELIMIT, "File passed is not regular, ignoring: %m");
+                return;
+        }
+
+        if (st.st_size <= 0)
+                return;
+
+        int flags = fcntl(fd, F_GETFL);
+        if (flags < 0) {
+                log_ratelimit_error_errno(errno, JOURNAL_LOG_RATELIMIT, "Failed to get flags of passed file, ignoring: %m");
+                return;
+        }
+
+        if ((flags & ~(O_ACCMODE|RAW_O_LARGEFILE)) != 0) {
+                log_ratelimit_error(JOURNAL_LOG_RATELIMIT, "Unexpected flags of passed memory fd, ignoring message: %m");
+                return;
+        }
+
+        /* If it's a memfd, check if it is sealed. If so, we can just mmap it and use it, and do not need to
+         * copy the data out. */
+        sealed = memfd_get_sealed(fd) > 0;
+
+        if (!sealed && (!ucred || ucred->uid != 0)) {
+                _cleanup_free_ char *k = NULL;
+                const char *e;
+
+                /* If this is not a sealed memfd, and the peer is unknown or
+                 * unprivileged, then verify the path. */
+
+                r = fd_get_path(fd, &k);
+                if (r < 0) {
+                        log_ratelimit_error_errno(r, JOURNAL_LOG_RATELIMIT,
+                                                  "readlink(/proc/self/fd/%i) failed: %m", fd);
+                        return;
+                }
+
+                e = PATH_STARTSWITH_SET(k, "/dev/shm/", "/tmp/", "/var/tmp/");
+                if (!e) {
+                        log_ratelimit_error(JOURNAL_LOG_RATELIMIT,
+                                            "Received file outside of allowed directories. Refusing.");
+                        return;
+                }
+
+                if (!filename_is_valid(e)) {
+                        log_ratelimit_error(JOURNAL_LOG_RATELIMIT,
+                                            "Received file in subdirectory of allowed directories. Refusing.");
+                        return;
+                }
+        }
+
+        /* When !sealed, set a lower memory limit. We have to read the file, effectively doubling memory
+         * use. */
+        if (st.st_size > ENTRY_SIZE_MAX / (sealed ? 1 : 2)) {
+                log_ratelimit_error(JOURNAL_LOG_RATELIMIT,
+                                    "File passed too large (%"PRIu64" bytes). Ignoring.",
+                                    (uint64_t) st.st_size);
+                return;
+        }
+
+        if (sealed) {
+                void *p;
+                size_t ps;
+
+                /* The file is sealed, we can just map it and use it. */
+
+                ps = PAGE_ALIGN(st.st_size);
+                assert(ps < SIZE_MAX);
+                p = mmap(NULL, ps, PROT_READ, MAP_PRIVATE, fd, 0);
+                if (p == MAP_FAILED) {
+                        log_ratelimit_error_errno(errno, JOURNAL_LOG_RATELIMIT,
+                                                  "Failed to map memfd, ignoring: %m");
+                        return;
+                }
+
+                server_process_native_message(s, p, st.st_size, ucred, tv, label, label_len);
+                assert_se(munmap(p, ps) >= 0);
+        } else {
+                _cleanup_free_ void *p = NULL;
+                struct statvfs vfs;
+                ssize_t n;
+
+                if (fstatvfs(fd, &vfs) < 0) {
+                        log_ratelimit_error_errno(errno, JOURNAL_LOG_RATELIMIT,
+                                                  "Failed to stat file system of passed file, not processing it: %m");
+                        return;
+                }
+
+                /* Refuse operating on file systems that have
+                 * mandatory locking enabled, see:
+                 *
+                 * https://github.com/systemd/systemd/issues/1822
+                 */
+                if (vfs.f_flag & ST_MANDLOCK) {
+                        log_ratelimit_error(JOURNAL_LOG_RATELIMIT,
+                                            "Received file descriptor from file system with mandatory locking enabled, not processing it.");
+                        return;
+                }
+
+                /* Make the fd non-blocking. On regular files this has
+                 * the effect of bypassing mandatory locking. Of
+                 * course, this should normally not be necessary given
+                 * the check above, but let's better be safe than
+                 * sorry, after all NFS is pretty confusing regarding
+                 * file system flags, and we better don't trust it,
+                 * and so is SMB. */
+                r = fd_nonblock(fd, true);
+                if (r < 0) {
+                        log_ratelimit_error_errno(r, JOURNAL_LOG_RATELIMIT,
+                                                  "Failed to make fd non-blocking, not processing it: %m");
+                        return;
+                }
+
+                /* The file is not sealed, we can't map the file here, since
+                 * clients might then truncate it and trigger a SIGBUS for
+                 * us. So let's stupidly read it. */
+
+                p = malloc(st.st_size);
+                if (!p) {
+                        log_oom();
+                        return;
+                }
+
+                n = pread(fd, p, st.st_size, 0);
+                if (n < 0)
+                        log_ratelimit_error_errno(errno, JOURNAL_LOG_RATELIMIT,
+                                                  "Failed to read file, ignoring: %m");
+                else if (n > 0)
+                        server_process_native_message(s, p, n, ucred, tv, label, label_len);
+        }
+}
+
+int server_open_native_socket(Server *s, const char *native_socket) {
+        int r;
+
+        assert(s);
+        assert(native_socket);
+
+        if (s->native_fd < 0) {
+                union sockaddr_union sa;
+                size_t sa_len;
+
+                r = sockaddr_un_set_path(&sa.un, native_socket);
+                if (r < 0)
+                        return log_error_errno(r, "Unable to use namespace path %s for AF_UNIX socket: %m", native_socket);
+                sa_len = r;
+
+                s->native_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
+                if (s->native_fd < 0)
+                        return log_error_errno(errno, "socket() failed: %m");
+
+                (void) sockaddr_un_unlink(&sa.un);
+
+                r = bind(s->native_fd, &sa.sa, sa_len);
+                if (r < 0)
+                        return log_error_errno(errno, "bind(%s) failed: %m", sa.un.sun_path);
+
+                (void) chmod(sa.un.sun_path, 0666);
+        } else
+                (void) fd_nonblock(s->native_fd, true);
+
+        r = setsockopt_int(s->native_fd, SOL_SOCKET, SO_PASSCRED, true);
+        if (r < 0)
+                return log_error_errno(r, "SO_PASSCRED failed: %m");
+
+        if (mac_selinux_use()) {
+                r = setsockopt_int(s->native_fd, SOL_SOCKET, SO_PASSSEC, true);
+                if (r < 0)
+                        log_warning_errno(r, "SO_PASSSEC failed: %m");
+        }
+
+        r = setsockopt_int(s->native_fd, SOL_SOCKET, SO_TIMESTAMP, true);
+        if (r < 0)
+                return log_error_errno(r, "SO_TIMESTAMP failed: %m");
+
+        r = sd_event_add_io(s->event, &s->native_event_source, s->native_fd, EPOLLIN, server_process_datagram, s);
+        if (r < 0)
+                return log_error_errno(r, "Failed to add native server fd to event loop: %m");
+
+        r = sd_event_source_set_priority(s->native_event_source, SD_EVENT_PRIORITY_NORMAL+5);
+        if (r < 0)
+                return log_error_errno(r, "Failed to adjust native event source priority: %m");
+
+        return 0;
+}