/*-*- 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" /* Make sure not to make this smaller than the maximum coredump * size. See COREDUMP_MAX in coredump.c */ #define ENTRY_SIZE_MAX (1024*1024*768) #define DATA_SIZE_MAX (1024*1024*768) static bool valid_user_field(const char *p, size_t l) { 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 (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)) { 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)) { 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); } 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; struct epoll_event ev; 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() failed: %m"); 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; } zero(ev); ev.events = EPOLLIN; ev.data.fd = s->native_fd; if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, s->native_fd, &ev) < 0) { log_error("Failed to add native server fd to epoll object: %m"); return -errno; } return 0; }