/*-*- 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 <sys/socket.h> #include <sys/un.h> #include <errno.h> #include <stddef.h> #include <unistd.h> #include <fcntl.h> #include <printf.h> #define SD_JOURNAL_SUPPRESS_LOCATION #include "sd-journal.h" #include "util.h" #include "socket-util.h" #define SNDBUF_SIZE (8*1024*1024) #define ALLOCA_CODE_FUNC(f, func) \ do { \ size_t _fl; \ const char *_func = (func); \ char **_f = &(f); \ _fl = strlen(_func) + 1; \ *_f = alloca(_fl + 10); \ memcpy(*_f, "CODE_FUNC=", 10); \ memcpy(*_f + 10, _func, _fl); \ } while(false) /* We open a single fd, and we'll share it with the current process, * all its threads, and all its subprocesses. This means we need to * initialize it atomically, and need to operate on it atomically * never assuming we are the only user */ static int journal_fd(void) { int fd; static int fd_plus_one = 0; retry: if (fd_plus_one > 0) return fd_plus_one - 1; fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0); if (fd < 0) return -errno; fd_inc_sndbuf(fd, SNDBUF_SIZE); if (!__sync_bool_compare_and_swap(&fd_plus_one, 0, fd+1)) { close_nointr_nofail(fd); goto retry; } return fd; } _public_ int sd_journal_print(int priority, const char *format, ...) { int r; va_list ap; va_start(ap, format); r = sd_journal_printv(priority, format, ap); va_end(ap); return r; } _public_ int sd_journal_printv(int priority, const char *format, va_list ap) { /* FIXME: Instead of limiting things to LINE_MAX we could do a C99 variable-length array on the stack here in a loop. */ char buffer[8 + LINE_MAX], p[11]; struct iovec iov[2]; if (priority < 0 || priority > 7) return -EINVAL; if (!format) return -EINVAL; snprintf(p, sizeof(p), "PRIORITY=%i", priority & LOG_PRIMASK); char_array_0(p); memcpy(buffer, "MESSAGE=", 8); vsnprintf(buffer+8, sizeof(buffer) - 8, format, ap); char_array_0(buffer); zero(iov); IOVEC_SET_STRING(iov[0], buffer); IOVEC_SET_STRING(iov[1], p); return sd_journal_sendv(iov, 2); } static int fill_iovec_sprintf(const char *format, va_list ap, int extra, struct iovec **_iov) { PROTECT_ERRNO; int r, n = 0, i = 0, j; struct iovec *iov = NULL; assert(_iov); if (extra > 0) { n = MAX(extra * 2, extra + 4); iov = malloc0(n * sizeof(struct iovec)); if (!iov) { r = -ENOMEM; goto fail; } i = extra; } while (format) { struct iovec *c; char *buffer; va_list aq; if (i >= n) { n = MAX(i*2, 4); c = realloc(iov, n * sizeof(struct iovec)); if (!c) { r = -ENOMEM; goto fail; } iov = c; } va_copy(aq, ap); if (vasprintf(&buffer, format, aq) < 0) { va_end(aq); r = -ENOMEM; goto fail; } va_end(aq); VA_FORMAT_ADVANCE(format, ap); IOVEC_SET_STRING(iov[i++], buffer); format = va_arg(ap, char *); } *_iov = iov; return i; fail: for (j = 0; j < i; j++) free(iov[j].iov_base); free(iov); return r; } _public_ int sd_journal_send(const char *format, ...) { int r, i, j; va_list ap; struct iovec *iov = NULL; va_start(ap, format); i = fill_iovec_sprintf(format, ap, 0, &iov); va_end(ap); if (_unlikely_(i < 0)) { r = i; goto finish; } r = sd_journal_sendv(iov, i); finish: for (j = 0; j < i; j++) free(iov[j].iov_base); free(iov); return r; } _public_ int sd_journal_sendv(const struct iovec *iov, int n) { PROTECT_ERRNO; int fd, buffer_fd; struct iovec *w; uint64_t *l; int i, j = 0; struct msghdr mh; struct sockaddr_un sa; ssize_t k; union { struct cmsghdr cmsghdr; uint8_t buf[CMSG_SPACE(sizeof(int))]; } control; struct cmsghdr *cmsg; /* We use /dev/shm instead of /tmp here, since we want this to * be a tmpfs, and one that is available from early boot on * and where unprivileged users can create files. */ char path[] = "/dev/shm/journal.XXXXXX"; bool have_syslog_identifier = false; if (_unlikely_(!iov)) return -EINVAL; if (_unlikely_(n <= 0)) return -EINVAL; w = alloca(sizeof(struct iovec) * n * 5 + 3); l = alloca(sizeof(uint64_t) * n); for (i = 0; i < n; i++) { char *c, *nl; if (_unlikely_(!iov[i].iov_base || iov[i].iov_len <= 1)) return -EINVAL; c = memchr(iov[i].iov_base, '=', iov[i].iov_len); if (_unlikely_(!c || c == iov[i].iov_base)) return -EINVAL; have_syslog_identifier = have_syslog_identifier || (c == (char *) iov[i].iov_base + 17 && memcmp(iov[i].iov_base, "SYSLOG_IDENTIFIER", 17) == 0); nl = memchr(iov[i].iov_base, '\n', iov[i].iov_len); if (nl) { if (_unlikely_(nl < c)) return -EINVAL; /* Already includes a newline? Bummer, then * let's write the variable name, then a * newline, then the size (64bit LE), followed * by the data and a final newline */ w[j].iov_base = iov[i].iov_base; w[j].iov_len = c - (char*) iov[i].iov_base; j++; IOVEC_SET_STRING(w[j++], "\n"); l[i] = htole64(iov[i].iov_len - (c - (char*) iov[i].iov_base) - 1); w[j].iov_base = &l[i]; w[j].iov_len = sizeof(uint64_t); j++; w[j].iov_base = c + 1; w[j].iov_len = iov[i].iov_len - (c - (char*) iov[i].iov_base) - 1; j++; } else /* Nothing special? Then just add the line and * append a newline */ w[j++] = iov[i]; IOVEC_SET_STRING(w[j++], "\n"); } if (!have_syslog_identifier && string_is_safe(program_invocation_short_name)) { /* Implicitly add program_invocation_short_name, if it * is not set explicitly. We only do this for * program_invocation_short_name, and nothing else * since everything else is much nicer to retrieve * from the outside. */ IOVEC_SET_STRING(w[j++], "SYSLOG_IDENTIFIER="); IOVEC_SET_STRING(w[j++], program_invocation_short_name); IOVEC_SET_STRING(w[j++], "\n"); } fd = journal_fd(); if (_unlikely_(fd < 0)) return fd; zero(sa); sa.sun_family = AF_UNIX; strncpy(sa.sun_path, "/run/systemd/journal/socket", sizeof(sa.sun_path)); zero(mh); mh.msg_name = &sa; mh.msg_namelen = offsetof(struct sockaddr_un, sun_path) + strlen(sa.sun_path); mh.msg_iov = w; mh.msg_iovlen = j; k = sendmsg(fd, &mh, MSG_NOSIGNAL); if (k >= 0) return 0; if (errno != EMSGSIZE && errno != ENOBUFS) return -errno; /* Message doesn't fit... Let's dump the data in a temporary * file and just pass a file descriptor of it to the other * side */ buffer_fd = mkostemp(path, O_CLOEXEC|O_RDWR); if (buffer_fd < 0) return -errno; if (unlink(path) < 0) { close_nointr_nofail(buffer_fd); return -errno; } n = writev(buffer_fd, w, j); if (n < 0) { close_nointr_nofail(buffer_fd); return -errno; } mh.msg_iov = NULL; mh.msg_iovlen = 0; zero(control); mh.msg_control = &control; mh.msg_controllen = sizeof(control); cmsg = CMSG_FIRSTHDR(&mh); cmsg->cmsg_level = SOL_SOCKET; cmsg->cmsg_type = SCM_RIGHTS; cmsg->cmsg_len = CMSG_LEN(sizeof(int)); memcpy(CMSG_DATA(cmsg), &buffer_fd, sizeof(int)); mh.msg_controllen = cmsg->cmsg_len; k = sendmsg(fd, &mh, MSG_NOSIGNAL); close_nointr_nofail(buffer_fd); if (k < 0) return -errno; return 0; } static int fill_iovec_perror_and_send(const char *message, int skip, struct iovec iov[]) { PROTECT_ERRNO; size_t n, k; k = isempty(message) ? 0 : strlen(message) + 2; n = 8 + k + 256 + 1; for (;;) { char buffer[n]; char* j; errno = 0; j = strerror_r(_saved_errno_, buffer + 8 + k, n - 8 - k); if (errno == 0) { char error[6 + 10 + 1]; /* for a 32bit value */ if (j != buffer + 8 + k) memmove(buffer + 8 + k, j, strlen(j)+1); memcpy(buffer, "MESSAGE=", 8); if (k > 0) { memcpy(buffer + 8, message, k - 2); memcpy(buffer + 8 + k - 2, ": ", 2); } snprintf(error, sizeof(error), "ERRNO=%u", _saved_errno_); char_array_0(error); IOVEC_SET_STRING(iov[skip+0], "PRIORITY=3"); IOVEC_SET_STRING(iov[skip+1], buffer); IOVEC_SET_STRING(iov[skip+2], error); return sd_journal_sendv(iov, skip + 3); } if (errno != ERANGE) return -errno; n *= 2; } } _public_ int sd_journal_perror(const char *message) { struct iovec iovec[3]; return fill_iovec_perror_and_send(message, 0, iovec); } _public_ int sd_journal_stream_fd(const char *identifier, int priority, int level_prefix) { union sockaddr_union sa; int fd; char *header; size_t l; ssize_t r; if (priority < 0 || priority > 7) return -EINVAL; fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0); if (fd < 0) return -errno; zero(sa); sa.un.sun_family = AF_UNIX; strncpy(sa.un.sun_path, "/run/systemd/journal/stdout", sizeof(sa.un.sun_path)); r = connect(fd, &sa.sa, offsetof(union sockaddr_union, un.sun_path) + strlen(sa.un.sun_path)); if (r < 0) { close_nointr_nofail(fd); return -errno; } if (shutdown(fd, SHUT_RD) < 0) { close_nointr_nofail(fd); return -errno; } fd_inc_sndbuf(fd, SNDBUF_SIZE); if (!identifier) identifier = ""; l = strlen(identifier); header = alloca(l + 1 + 1 + 2 + 2 + 2 + 2 + 2); memcpy(header, identifier, l); header[l++] = '\n'; header[l++] = '\n'; /* unit id */ header[l++] = '0' + priority; header[l++] = '\n'; header[l++] = '0' + !!level_prefix; header[l++] = '\n'; header[l++] = '0'; header[l++] = '\n'; header[l++] = '0'; header[l++] = '\n'; header[l++] = '0'; header[l++] = '\n'; r = loop_write(fd, header, l, false); if (r < 0) { close_nointr_nofail(fd); return (int) r; } if ((size_t) r != l) { close_nointr_nofail(fd); return -errno; } return fd; } _public_ int sd_journal_print_with_location(int priority, const char *file, const char *line, const char *func, const char *format, ...) { int r; va_list ap; va_start(ap, format); r = sd_journal_printv_with_location(priority, file, line, func, format, ap); va_end(ap); return r; } _public_ int sd_journal_printv_with_location(int priority, const char *file, const char *line, const char *func, const char *format, va_list ap) { char buffer[8 + LINE_MAX], p[11]; struct iovec iov[5]; char *f; if (priority < 0 || priority > 7) return -EINVAL; if (_unlikely_(!format)) return -EINVAL; snprintf(p, sizeof(p), "PRIORITY=%i", priority & LOG_PRIMASK); char_array_0(p); memcpy(buffer, "MESSAGE=", 8); vsnprintf(buffer+8, sizeof(buffer) - 8, format, ap); char_array_0(buffer); /* func is initialized from __func__ which is not a macro, but * a static const char[], hence cannot easily be prefixed with * CODE_FUNC=, hence let's do it manually here. */ ALLOCA_CODE_FUNC(f, func); zero(iov); IOVEC_SET_STRING(iov[0], buffer); IOVEC_SET_STRING(iov[1], p); IOVEC_SET_STRING(iov[2], file); IOVEC_SET_STRING(iov[3], line); IOVEC_SET_STRING(iov[4], f); return sd_journal_sendv(iov, ELEMENTSOF(iov)); } _public_ int sd_journal_send_with_location(const char *file, const char *line, const char *func, const char *format, ...) { int r, i, j; va_list ap; struct iovec *iov = NULL; char *f; va_start(ap, format); i = fill_iovec_sprintf(format, ap, 3, &iov); va_end(ap); if (_unlikely_(i < 0)) { r = i; goto finish; } ALLOCA_CODE_FUNC(f, func); IOVEC_SET_STRING(iov[0], file); IOVEC_SET_STRING(iov[1], line); IOVEC_SET_STRING(iov[2], f); r = sd_journal_sendv(iov, i); finish: for (j = 3; j < i; j++) free(iov[j].iov_base); free(iov); return r; } _public_ int sd_journal_sendv_with_location( const char *file, const char *line, const char *func, const struct iovec *iov, int n) { struct iovec *niov; char *f; if (_unlikely_(!iov)) return -EINVAL; if (_unlikely_(n <= 0)) return -EINVAL; niov = alloca(sizeof(struct iovec) * (n + 3)); memcpy(niov, iov, sizeof(struct iovec) * n); ALLOCA_CODE_FUNC(f, func); IOVEC_SET_STRING(niov[n++], file); IOVEC_SET_STRING(niov[n++], line); IOVEC_SET_STRING(niov[n++], f); return sd_journal_sendv(niov, n); } _public_ int sd_journal_perror_with_location( const char *file, const char *line, const char *func, const char *message) { struct iovec iov[6]; char *f; ALLOCA_CODE_FUNC(f, func); IOVEC_SET_STRING(iov[0], file); IOVEC_SET_STRING(iov[1], line); IOVEC_SET_STRING(iov[2], f); return fill_iovec_perror_and_send(message, 3, iov); }