| /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
| |
| /*** |
| 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 <unistd.h> |
| #include <stddef.h> |
| #include <sys/epoll.h> |
| |
| #include "socket-util.h" |
| #include "path-util.h" |
| #include "selinux-util.h" |
| #include "journald-server.h" |
| #include "journald-native.h" |
| #include "journald-kmsg.h" |
| #include "journald-console.h" |
| #include "journald-syslog.h" |
| #include "journald-wall.h" |
| |
| bool valid_user_field(const char *p, size_t l, bool allow_protected) { |
| const char *a; |
| |
| /* We kinda enforce POSIX syntax recommendations for |
| environment variables here, but make a couple of additional |
| requirements. |
| |
| http://pubs.opengroup.org/onlinepubs/000095399/basedefs/xbd_chap08.html */ |
| |
| /* No empty field names */ |
| if (l <= 0) |
| return false; |
| |
| /* Don't allow names longer than 64 chars */ |
| if (l > 64) |
| return false; |
| |
| /* Variables starting with an underscore are protected */ |
| if (!allow_protected && p[0] == '_') |
| return false; |
| |
| /* Don't allow digits as first character */ |
| if (p[0] >= '0' && p[0] <= '9') |
| return false; |
| |
| /* Only allow A-Z0-9 and '_' */ |
| for (a = p; a < p + l; a++) |
| if ((*a < 'A' || *a > 'Z') && |
| (*a < '0' || *a > '9') && |
| *a != '_') |
| return false; |
| |
| return true; |
| } |
| |
| static bool allow_object_pid(struct ucred *ucred) { |
| return ucred && ucred->uid == 0; |
| } |
| |
| void server_process_native_message( |
| Server *s, |
| const void *buffer, size_t buffer_size, |
| struct ucred *ucred, |
| struct timeval *tv, |
| const char *label, size_t label_len) { |
| |
| struct iovec *iovec = NULL; |
| unsigned n = 0, j, tn = (unsigned) -1; |
| const char *p; |
| size_t remaining, m = 0; |
| int priority = LOG_INFO; |
| char *identifier = NULL, *message = NULL; |
| pid_t object_pid = 0; |
| |
| assert(s); |
| assert(buffer || buffer_size == 0); |
| |
| p = buffer; |
| remaining = buffer_size; |
| |
| 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; |
| } |
| |
| if (e == p) { |
| /* Entry separator */ |
| server_dispatch_message(s, iovec, n, m, ucred, tv, label, label_len, NULL, priority, object_pid); |
| n = 0; |
| priority = LOG_INFO; |
| |
| p++; |
| remaining--; |
| continue; |
| } |
| |
| if (*p == '.' || *p == '#') { |
| /* Ignore control commands for now, and |
| * comments too. */ |
| remaining -= (e - p) + 1; |
| p = e + 1; |
| continue; |
| } |
| |
| /* A property follows */ |
| |
| /* n received properties, +1 for _TRANSPORT */ |
| if (!GREEDY_REALLOC(iovec, m, n + 1 + N_IOVEC_META_FIELDS + |
| !!object_pid * N_IOVEC_OBJECT_FIELDS)) { |
| log_oom(); |
| break; |
| } |
| |
| q = memchr(p, '=', e - p); |
| if (q) { |
| if (valid_user_field(p, q - p, false)) { |
| size_t l; |
| |
| l = e - p; |
| |
| /* If the field name starts with an |
| * underscore, skip the variable, |
| * since that indidates a trusted |
| * field */ |
| iovec[n].iov_base = (char*) p; |
| iovec[n].iov_len = l; |
| n++; |
| |
| /* 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 = strndup(p + 18, l - 18); |
| if (t) { |
| free(identifier); |
| identifier = t; |
| } |
| } else if (l >= 8 && |
| startswith(p, "MESSAGE=")) { |
| char *t; |
| |
| t = strndup(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=")); |
| char_array_0(buf); |
| |
| /* ignore error */ |
| parse_pid(buf, &object_pid); |
| } |
| } |
| |
| remaining -= (e - p) + 1; |
| p = e + 1; |
| continue; |
| } else { |
| le64_t l_le; |
| uint64_t l; |
| char *k; |
| |
| if (remaining < e - p + 1 + sizeof(uint64_t) + 1) { |
| log_debug("Failed to parse message, ignoring."); |
| break; |
| } |
| |
| memcpy(&l_le, e + 1, sizeof(uint64_t)); |
| l = le64toh(l_le); |
| |
| if (l > DATA_SIZE_MAX) { |
| log_debug("Received binary data block too large, ignoring."); |
| break; |
| } |
| |
| 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((e - p) + 1 + l); |
| 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 (valid_user_field(p, e - p, false)) { |
| iovec[n].iov_base = k; |
| iovec[n].iov_len = (e - p) + 1 + l; |
| n++; |
| } 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_SET_STRING(iovec[tn], "_TRANSPORT=journal"); |
| |
| if (message) { |
| if (s->forward_to_syslog) |
| server_forward_syslog(s, 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, m, ucred, tv, label, label_len, NULL, priority, object_pid); |
| |
| finish: |
| for (j = 0; j < n; j++) { |
| if (j == tn) |
| continue; |
| |
| if (iovec[j].iov_base < buffer || |
| (const uint8_t*) iovec[j].iov_base >= (const uint8_t*) buffer + buffer_size) |
| free(iovec[j].iov_base); |
| } |
| |
| free(iovec); |
| free(identifier); |
| free(message); |
| } |
| |
| void server_process_native_file( |
| Server *s, |
| int fd, |
| struct ucred *ucred, |
| struct timeval *tv, |
| const char *label, size_t label_len) { |
| |
| struct stat st; |
| _cleanup_free_ void *p = NULL; |
| ssize_t n; |
| int r; |
| |
| assert(s); |
| assert(fd >= 0); |
| |
| if (!ucred || ucred->uid != 0) { |
| _cleanup_free_ char *sl = NULL, *k = NULL; |
| const char *e; |
| |
| if (asprintf(&sl, "/proc/self/fd/%i", fd) < 0) { |
| log_oom(); |
| return; |
| } |
| |
| r = readlink_malloc(sl, &k); |
| if (r < 0) { |
| log_error("readlink(%s) failed: %m", sl); |
| return; |
| } |
| |
| e = path_startswith(k, "/dev/shm/"); |
| if (!e) |
| e = path_startswith(k, "/tmp/"); |
| if (!e) |
| e = path_startswith(k, "/var/tmp/"); |
| if (!e) { |
| log_error("Received file outside of allowed directories. Refusing."); |
| return; |
| } |
| |
| if (!filename_is_safe(e)) { |
| log_error("Received file in subdirectory of allowed directories. Refusing."); |
| return; |
| } |
| } |
| |
| /* Data is in the passed file, since it didn't fit in a |
| * datagram. 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 */ |
| |
| if (fstat(fd, &st) < 0) { |
| log_error("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; |
| |
| if (st.st_size > ENTRY_SIZE_MAX) { |
| log_error("File passed too large. Ignoring."); |
| return; |
| } |
| |
| p = malloc(st.st_size); |
| if (!p) { |
| log_oom(); |
| return; |
| } |
| |
| n = pread(fd, p, st.st_size, 0); |
| if (n < 0) |
| log_error("Failed to read file, ignoring: %s", strerror(-n)); |
| else if (n > 0) |
| server_process_native_message(s, p, n, ucred, tv, label, label_len); |
| } |
| |
| int server_open_native_socket(Server*s) { |
| union sockaddr_union sa; |
| int one, r; |
| |
| assert(s); |
| |
| if (s->native_fd < 0) { |
| |
| s->native_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); |
| if (s->native_fd < 0) { |
| log_error("socket() failed: %m"); |
| return -errno; |
| } |
| |
| zero(sa); |
| sa.un.sun_family = AF_UNIX; |
| strncpy(sa.un.sun_path, "/run/systemd/journal/socket", sizeof(sa.un.sun_path)); |
| |
| unlink(sa.un.sun_path); |
| |
| r = bind(s->native_fd, &sa.sa, offsetof(union sockaddr_union, un.sun_path) + strlen(sa.un.sun_path)); |
| if (r < 0) { |
| log_error("bind(%s) failed: %m", sa.un.sun_path); |
| return -errno; |
| } |
| |
| chmod(sa.un.sun_path, 0666); |
| } else |
| fd_nonblock(s->native_fd, 1); |
| |
| one = 1; |
| r = setsockopt(s->native_fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one)); |
| if (r < 0) { |
| log_error("SO_PASSCRED failed: %m"); |
| return -errno; |
| } |
| |
| #ifdef HAVE_SELINUX |
| if (use_selinux()) { |
| one = 1; |
| r = setsockopt(s->native_fd, SOL_SOCKET, SO_PASSSEC, &one, sizeof(one)); |
| if (r < 0) |
| log_warning("SO_PASSSEC failed: %m"); |
| } |
| #endif |
| |
| one = 1; |
| r = setsockopt(s->native_fd, SOL_SOCKET, SO_TIMESTAMP, &one, sizeof(one)); |
| if (r < 0) { |
| log_error("SO_TIMESTAMP failed: %m"); |
| return -errno; |
| } |
| |
| r = sd_event_add_io(s->event, &s->native_event_source, s->native_fd, EPOLLIN, process_datagram, s); |
| if (r < 0) { |
| log_error("Failed to add native server fd to event loop: %s", strerror(-r)); |
| return r; |
| } |
| |
| return 0; |
| } |