| /* 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 "io-util.h" |
| #include "journal-importer.h" |
| #include "journal-util.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 "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(*identifier); |
| *identifier = t; |
| } |
| |
| } else if (l >= 8 && |
| startswith(p, "MESSAGE=")) { |
| char *t; |
| |
| t = memdup_suffix0(p + 8, l - 8); |
| if (t) { |
| free(*message); |
| *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) { |
| 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_warning_errno(r, "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 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_error_errno(r, "readlink(/proc/self/fd/%i) failed: %m", fd); |
| return; |
| } |
| |
| e = PATH_STARTSWITH_SET(k, "/dev/shm/", "/tmp/", "/var/tmp/"); |
| if (!e) { |
| log_error("Received file outside of allowed directories. Refusing."); |
| return; |
| } |
| |
| if (!filename_is_valid(e)) { |
| log_error("Received file in subdirectory of allowed directories. Refusing."); |
| return; |
| } |
| } |
| |
| if (fstat(fd, &st) < 0) { |
| log_error_errno(errno, "Failed to stat passed file, ignoring: %m"); |
| return; |
| } |
| |
| if (!S_ISREG(st.st_mode)) { |
| log_error("File passed is not regular. Ignoring."); |
| return; |
| } |
| |
| if (st.st_size <= 0) |
| 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_error("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); |
| p = mmap(NULL, ps, PROT_READ, MAP_PRIVATE, fd, 0); |
| if (p == MAP_FAILED) { |
| log_error_errno(errno, "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_error_errno(errno, "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_error("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_error_errno(r, "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_error_errno(errno, "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; |
| } |
