X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Flibsystemd-bus%2Fbus-socket.c;fp=src%2Flibsystemd-bus%2Fbus-socket.c;h=0000000000000000000000000000000000000000;hp=0c4b6af447297fbe8f1e348f096df36d879f37d9;hb=6bb648a16ae4a682ad4784412af706d2e6a3e4da;hpb=883b36908788361a8bb945ce884dc518da83b371 diff --git a/src/libsystemd-bus/bus-socket.c b/src/libsystemd-bus/bus-socket.c deleted file mode 100644 index 0c4b6af44..000000000 --- a/src/libsystemd-bus/bus-socket.c +++ /dev/null @@ -1,1105 +0,0 @@ -/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ - -/*** - This file is part of systemd. - - Copyright 2013 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 . -***/ - -#include -#include -#include -#include -#include -#include - -#include "util.h" -#include "macro.h" -#include "missing.h" -#include "strv.h" -#include "utf8.h" -#include "sd-daemon.h" - -#include "sd-bus.h" -#include "bus-socket.h" -#include "bus-internal.h" -#include "bus-message.h" - -#define SNDBUF_SIZE (8*1024*1024) - -static void iovec_advance(struct iovec iov[], unsigned *idx, size_t size) { - - while (size > 0) { - struct iovec *i = iov + *idx; - - if (i->iov_len > size) { - i->iov_base = (uint8_t*) i->iov_base + size; - i->iov_len -= size; - return; - } - - size -= i->iov_len; - - i->iov_base = NULL; - i->iov_len = 0; - - (*idx) ++; - } -} - -static int append_iovec(sd_bus_message *m, const void *p, size_t sz) { - assert(m); - assert(p); - assert(sz > 0); - - m->iovec[m->n_iovec].iov_base = (void*) p; - m->iovec[m->n_iovec].iov_len = sz; - m->n_iovec++; - - return 0; -} - -static int bus_message_setup_iovec(sd_bus_message *m) { - struct bus_body_part *part; - unsigned n, i; - int r; - - assert(m); - assert(m->sealed); - - if (m->n_iovec > 0) - return 0; - - assert(!m->iovec); - - n = 1 + m->n_body_parts; - if (n < ELEMENTSOF(m->iovec_fixed)) - m->iovec = m->iovec_fixed; - else { - m->iovec = new(struct iovec, n); - if (!m->iovec) { - r = -ENOMEM; - goto fail; - } - } - - r = append_iovec(m, m->header, BUS_MESSAGE_BODY_BEGIN(m)); - if (r < 0) - goto fail; - - MESSAGE_FOREACH_PART(part, i, m) { - r = bus_body_part_map(part); - if (r < 0) - goto fail; - - r = append_iovec(m, part->data, part->size); - if (r < 0) - goto fail; - } - - assert(n == m->n_iovec); - - return 0; - -fail: - m->poisoned = true; - return r; -} - -bool bus_socket_auth_needs_write(sd_bus *b) { - - unsigned i; - - if (b->auth_index >= ELEMENTSOF(b->auth_iovec)) - return false; - - for (i = b->auth_index; i < ELEMENTSOF(b->auth_iovec); i++) { - struct iovec *j = b->auth_iovec + i; - - if (j->iov_len > 0) - return true; - } - - return false; -} - -static int bus_socket_write_auth(sd_bus *b) { - ssize_t k; - - assert(b); - assert(b->state == BUS_AUTHENTICATING); - - if (!bus_socket_auth_needs_write(b)) - return 0; - - if (b->prefer_writev) - k = writev(b->output_fd, b->auth_iovec + b->auth_index, ELEMENTSOF(b->auth_iovec) - b->auth_index); - else { - struct msghdr mh; - zero(mh); - - mh.msg_iov = b->auth_iovec + b->auth_index; - mh.msg_iovlen = ELEMENTSOF(b->auth_iovec) - b->auth_index; - - k = sendmsg(b->output_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL); - if (k < 0 && errno == ENOTSOCK) { - b->prefer_writev = true; - k = writev(b->output_fd, b->auth_iovec + b->auth_index, ELEMENTSOF(b->auth_iovec) - b->auth_index); - } - } - - if (k < 0) - return errno == EAGAIN ? 0 : -errno; - - iovec_advance(b->auth_iovec, &b->auth_index, (size_t) k); - return 1; -} - -static int bus_socket_auth_verify_client(sd_bus *b) { - char *e, *f, *start; - sd_id128_t peer; - unsigned i; - int r; - - assert(b); - - /* We expect two response lines: "OK" and possibly - * "AGREE_UNIX_FD" */ - - e = memmem(b->rbuffer, b->rbuffer_size, "\r\n", 2); - if (!e) - return 0; - - if (b->hello_flags & KDBUS_HELLO_ACCEPT_FD) { - f = memmem(e + 2, b->rbuffer_size - (e - (char*) b->rbuffer) - 2, "\r\n", 2); - if (!f) - return 0; - - start = f + 2; - } else { - f = NULL; - start = e + 2; - } - - /* Nice! We got all the lines we need. First check the OK - * line */ - - if (e - (char*) b->rbuffer != 3 + 32) - return -EPERM; - - if (memcmp(b->rbuffer, "OK ", 3)) - return -EPERM; - - b->auth = b->anonymous_auth ? BUS_AUTH_ANONYMOUS : BUS_AUTH_EXTERNAL; - - for (i = 0; i < 32; i += 2) { - int x, y; - - x = unhexchar(((char*) b->rbuffer)[3 + i]); - y = unhexchar(((char*) b->rbuffer)[3 + i + 1]); - - if (x < 0 || y < 0) - return -EINVAL; - - peer.bytes[i/2] = ((uint8_t) x << 4 | (uint8_t) y); - } - - if (!sd_id128_equal(b->server_id, SD_ID128_NULL) && - !sd_id128_equal(b->server_id, peer)) - return -EPERM; - - b->server_id = peer; - - /* And possibly check the second line, too */ - - if (f) - b->can_fds = - (f - e == sizeof("\r\nAGREE_UNIX_FD") - 1) && - memcmp(e + 2, "AGREE_UNIX_FD", sizeof("AGREE_UNIX_FD") - 1) == 0; - - b->rbuffer_size -= (start - (char*) b->rbuffer); - memmove(b->rbuffer, start, b->rbuffer_size); - - r = bus_start_running(b); - if (r < 0) - return r; - - return 1; -} - -static bool line_equals(const char *s, size_t m, const char *line) { - size_t l; - - l = strlen(line); - if (l != m) - return false; - - return memcmp(s, line, l) == 0; -} - -static bool line_begins(const char *s, size_t m, const char *word) { - size_t l; - - l = strlen(word); - if (m < l) - return false; - - if (memcmp(s, word, l) != 0) - return false; - - return m == l || (m > l && s[l] == ' '); -} - -static int verify_anonymous_token(sd_bus *b, const char *p, size_t l) { - _cleanup_free_ char *token = NULL; - - if (!b->anonymous_auth) - return 0; - - if (l <= 0) - return 1; - - assert(p[0] == ' '); - p++; l--; - - if (l % 2 != 0) - return 0; - token = unhexmem(p, l); - if (!token) - return -ENOMEM; - - if (memchr(token, 0, l/2)) - return 0; - - return !!utf8_is_valid(token); -} - -static int verify_external_token(sd_bus *b, const char *p, size_t l) { - _cleanup_free_ char *token = NULL; - uid_t u; - int r; - - /* We don't do any real authentication here. Instead, we if - * the owner of this bus wanted authentication he should have - * checked SO_PEERCRED before even creating the bus object. */ - - if (!b->anonymous_auth && !b->ucred_valid) - return 0; - - if (l <= 0) - return 1; - - assert(p[0] == ' '); - p++; l--; - - if (l % 2 != 0) - return 0; - - token = unhexmem(p, l); - if (!token) - return -ENOMEM; - - if (memchr(token, 0, l/2)) - return 0; - - r = parse_uid(token, &u); - if (r < 0) - return 0; - - /* We ignore the passed value if anonymous authentication is - * on anyway. */ - if (!b->anonymous_auth && u != b->ucred.uid) - return 0; - - return 1; -} - -static int bus_socket_auth_write(sd_bus *b, const char *t) { - char *p; - size_t l; - - assert(b); - assert(t); - - /* We only make use of the first iovec */ - assert(b->auth_index == 0 || b->auth_index == 1); - - l = strlen(t); - p = malloc(b->auth_iovec[0].iov_len + l); - if (!p) - return -ENOMEM; - - memcpy(p, b->auth_iovec[0].iov_base, b->auth_iovec[0].iov_len); - memcpy(p + b->auth_iovec[0].iov_len, t, l); - - b->auth_iovec[0].iov_base = p; - b->auth_iovec[0].iov_len += l; - - free(b->auth_buffer); - b->auth_buffer = p; - b->auth_index = 0; - return 0; -} - -static int bus_socket_auth_write_ok(sd_bus *b) { - char t[3 + 32 + 2 + 1]; - - assert(b); - - snprintf(t, sizeof(t), "OK " SD_ID128_FORMAT_STR "\r\n", SD_ID128_FORMAT_VAL(b->server_id)); - char_array_0(t); - - return bus_socket_auth_write(b, t); -} - -static int bus_socket_auth_verify_server(sd_bus *b) { - char *e; - const char *line; - size_t l; - bool processed = false; - int r; - - assert(b); - - if (b->rbuffer_size < 1) - return 0; - - /* First char must be a NUL byte */ - if (*(char*) b->rbuffer != 0) - return -EIO; - - if (b->rbuffer_size < 3) - return 0; - - /* Begin with the first line */ - if (b->auth_rbegin <= 0) - b->auth_rbegin = 1; - - for (;;) { - /* Check if line is complete */ - line = (char*) b->rbuffer + b->auth_rbegin; - e = memmem(line, b->rbuffer_size - b->auth_rbegin, "\r\n", 2); - if (!e) - return processed; - - l = e - line; - - if (line_begins(line, l, "AUTH ANONYMOUS")) { - - r = verify_anonymous_token(b, line + 14, l - 14); - if (r < 0) - return r; - if (r == 0) - r = bus_socket_auth_write(b, "REJECTED\r\n"); - else { - b->auth = BUS_AUTH_ANONYMOUS; - r = bus_socket_auth_write_ok(b); - } - - } else if (line_begins(line, l, "AUTH EXTERNAL")) { - - r = verify_external_token(b, line + 13, l - 13); - if (r < 0) - return r; - if (r == 0) - r = bus_socket_auth_write(b, "REJECTED\r\n"); - else { - b->auth = BUS_AUTH_EXTERNAL; - r = bus_socket_auth_write_ok(b); - } - - } else if (line_begins(line, l, "AUTH")) - r = bus_socket_auth_write(b, "REJECTED EXTERNAL ANONYMOUS\r\n"); - else if (line_equals(line, l, "CANCEL") || - line_begins(line, l, "ERROR")) { - - b->auth = _BUS_AUTH_INVALID; - r = bus_socket_auth_write(b, "REJECTED\r\n"); - - } else if (line_equals(line, l, "BEGIN")) { - - if (b->auth == _BUS_AUTH_INVALID) - r = bus_socket_auth_write(b, "ERROR\r\n"); - else { - /* We can't leave from the auth phase - * before we haven't written - * everything queued, so let's check - * that */ - - if (bus_socket_auth_needs_write(b)) - return 1; - - b->rbuffer_size -= (e + 2 - (char*) b->rbuffer); - memmove(b->rbuffer, e + 2, b->rbuffer_size); - return bus_start_running(b); - } - - } else if (line_begins(line, l, "DATA")) { - - if (b->auth == _BUS_AUTH_INVALID) - r = bus_socket_auth_write(b, "ERROR\r\n"); - else { - if (b->auth == BUS_AUTH_ANONYMOUS) - r = verify_anonymous_token(b, line + 4, l - 4); - else - r = verify_external_token(b, line + 4, l - 4); - - if (r < 0) - return r; - if (r == 0) { - b->auth = _BUS_AUTH_INVALID; - r = bus_socket_auth_write(b, "REJECTED\r\n"); - } else - r = bus_socket_auth_write_ok(b); - } - } else if (line_equals(line, l, "NEGOTIATE_UNIX_FD")) { - if (b->auth == _BUS_AUTH_INVALID || !(b->hello_flags & KDBUS_HELLO_ACCEPT_FD)) - r = bus_socket_auth_write(b, "ERROR\r\n"); - else { - b->can_fds = true; - r = bus_socket_auth_write(b, "AGREE_UNIX_FD\r\n"); - } - } else - r = bus_socket_auth_write(b, "ERROR\r\n"); - - if (r < 0) - return r; - - b->auth_rbegin = e + 2 - (char*) b->rbuffer; - - processed = true; - } -} - -static int bus_socket_auth_verify(sd_bus *b) { - assert(b); - - if (b->is_server) - return bus_socket_auth_verify_server(b); - else - return bus_socket_auth_verify_client(b); -} - -static int bus_socket_read_auth(sd_bus *b) { - struct msghdr mh; - struct iovec iov; - size_t n; - ssize_t k; - int r; - void *p; - union { - struct cmsghdr cmsghdr; - uint8_t buf[CMSG_SPACE(sizeof(int) * BUS_FDS_MAX) + - CMSG_SPACE(sizeof(struct ucred)) + - CMSG_SPACE(NAME_MAX)]; /*selinux label */ - } control; - struct cmsghdr *cmsg; - bool handle_cmsg = false; - - assert(b); - assert(b->state == BUS_AUTHENTICATING); - - r = bus_socket_auth_verify(b); - if (r != 0) - return r; - - n = MAX(256u, b->rbuffer_size * 2); - - if (n > BUS_AUTH_SIZE_MAX) - n = BUS_AUTH_SIZE_MAX; - - if (b->rbuffer_size >= n) - return -ENOBUFS; - - p = realloc(b->rbuffer, n); - if (!p) - return -ENOMEM; - - b->rbuffer = p; - - zero(iov); - iov.iov_base = (uint8_t*) b->rbuffer + b->rbuffer_size; - iov.iov_len = n - b->rbuffer_size; - - if (b->prefer_readv) - k = readv(b->input_fd, &iov, 1); - else { - zero(mh); - mh.msg_iov = &iov; - mh.msg_iovlen = 1; - mh.msg_control = &control; - mh.msg_controllen = sizeof(control); - - k = recvmsg(b->input_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC); - if (k < 0 && errno == ENOTSOCK) { - b->prefer_readv = true; - k = readv(b->input_fd, &iov, 1); - } else - handle_cmsg = true; - } - if (k < 0) - return errno == EAGAIN ? 0 : -errno; - if (k == 0) - return -ECONNRESET; - - b->rbuffer_size += k; - - if (handle_cmsg) { - for (cmsg = CMSG_FIRSTHDR(&mh); cmsg; cmsg = CMSG_NXTHDR(&mh, cmsg)) { - if (cmsg->cmsg_level == SOL_SOCKET && - cmsg->cmsg_type == SCM_RIGHTS) { - int j; - - /* Whut? We received fds during the auth - * protocol? Somebody is playing games with - * us. Close them all, and fail */ - j = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int); - close_many((int*) CMSG_DATA(cmsg), j); - return -EIO; - - } else if (cmsg->cmsg_level == SOL_SOCKET && - cmsg->cmsg_type == SCM_CREDENTIALS && - cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) { - - /* Ignore bogus data, which we might - * get on socketpair() sockets */ - if (((struct ucred*) CMSG_DATA(cmsg))->pid != 0) { - memcpy(&b->ucred, CMSG_DATA(cmsg), sizeof(struct ucred)); - b->ucred_valid = true; - } - - } else if (cmsg->cmsg_level == SOL_SOCKET && - cmsg->cmsg_type == SCM_SECURITY) { - - size_t l; - - l = cmsg->cmsg_len - CMSG_LEN(0); - if (l > 0) { - memcpy(&b->label, CMSG_DATA(cmsg), l); - b->label[l] = 0; - } - } - } - } - - r = bus_socket_auth_verify(b); - if (r != 0) - return r; - - return 1; -} - -void bus_socket_setup(sd_bus *b) { - int enable; - - assert(b); - - /* Enable SO_PASSCRED + SO_PASSEC. We try this on any - * socket, just in case. */ - enable = !b->bus_client; - setsockopt(b->input_fd, SOL_SOCKET, SO_PASSCRED, &enable, sizeof(enable)); - - enable = !b->bus_client && (b->attach_flags & KDBUS_ATTACH_SECLABEL); - setsockopt(b->input_fd, SOL_SOCKET, SO_PASSSEC, &enable, sizeof(enable)); - - /* Increase the buffers to 8 MB */ - fd_inc_rcvbuf(b->input_fd, SNDBUF_SIZE); - fd_inc_sndbuf(b->output_fd, SNDBUF_SIZE); - - b->is_kernel = false; - b->message_version = 1; - b->message_endian = 0; -} - -static void bus_get_peercred(sd_bus *b) { - assert(b); - - /* Get the peer for socketpair() sockets */ - b->ucred_valid = getpeercred(b->input_fd, &b->ucred) >= 0; -} - -static int bus_socket_start_auth_client(sd_bus *b) { - size_t l; - const char *auth_suffix, *auth_prefix; - - assert(b); - - if (b->anonymous_auth) { - auth_prefix = "\0AUTH ANONYMOUS "; - - /* For ANONYMOUS auth we send some arbitrary "trace" string */ - l = 9; - b->auth_buffer = hexmem("anonymous", l); - } else { - char text[20 + 1]; /* enough space for a 64bit integer plus NUL */ - - auth_prefix = "\0AUTH EXTERNAL "; - - snprintf(text, sizeof(text), "%lu", (unsigned long) geteuid()); - char_array_0(text); - - l = strlen(text); - b->auth_buffer = hexmem(text, l); - } - - if (!b->auth_buffer) - return -ENOMEM; - - if (b->hello_flags & KDBUS_HELLO_ACCEPT_FD) - auth_suffix = "\r\nNEGOTIATE_UNIX_FD\r\nBEGIN\r\n"; - else - auth_suffix = "\r\nBEGIN\r\n"; - - b->auth_iovec[0].iov_base = (void*) auth_prefix; - b->auth_iovec[0].iov_len = 1 + strlen(auth_prefix + 1); - b->auth_iovec[1].iov_base = (void*) b->auth_buffer; - b->auth_iovec[1].iov_len = l * 2; - b->auth_iovec[2].iov_base = (void*) auth_suffix; - b->auth_iovec[2].iov_len = strlen(auth_suffix); - - return bus_socket_write_auth(b); -} - -int bus_socket_start_auth(sd_bus *b) { - assert(b); - - bus_get_peercred(b); - - b->state = BUS_AUTHENTICATING; - b->auth_timeout = now(CLOCK_MONOTONIC) + BUS_DEFAULT_TIMEOUT; - - if (sd_is_socket(b->input_fd, AF_UNIX, 0, 0) <= 0) - b->hello_flags &= ~KDBUS_HELLO_ACCEPT_FD; - - if (b->output_fd != b->input_fd) - if (sd_is_socket(b->output_fd, AF_UNIX, 0, 0) <= 0) - b->hello_flags &= ~KDBUS_HELLO_ACCEPT_FD; - - if (b->is_server) - return bus_socket_read_auth(b); - else - return bus_socket_start_auth_client(b); -} - -int bus_socket_connect(sd_bus *b) { - int r; - - assert(b); - assert(b->input_fd < 0); - assert(b->output_fd < 0); - assert(b->sockaddr.sa.sa_family != AF_UNSPEC); - - b->input_fd = socket(b->sockaddr.sa.sa_family, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); - if (b->input_fd < 0) - return -errno; - - b->output_fd = b->input_fd; - - bus_socket_setup(b); - - r = connect(b->input_fd, &b->sockaddr.sa, b->sockaddr_size); - if (r < 0) { - if (errno == EINPROGRESS) - return 1; - - return -errno; - } - - return bus_socket_start_auth(b); -} - -int bus_socket_exec(sd_bus *b) { - int s[2], r; - pid_t pid; - - assert(b); - assert(b->input_fd < 0); - assert(b->output_fd < 0); - assert(b->exec_path); - - r = socketpair(AF_UNIX, SOCK_STREAM|SOCK_NONBLOCK|SOCK_CLOEXEC, 0, s); - if (r < 0) - return -errno; - - pid = fork(); - if (pid < 0) { - close_pipe(s); - return -errno; - } - if (pid == 0) { - /* Child */ - - reset_all_signal_handlers(); - - close_all_fds(s+1, 1); - - assert_se(dup3(s[1], STDIN_FILENO, 0) == STDIN_FILENO); - assert_se(dup3(s[1], STDOUT_FILENO, 0) == STDOUT_FILENO); - - if (s[1] != STDIN_FILENO && s[1] != STDOUT_FILENO) - close_nointr_nofail(s[1]); - - fd_cloexec(STDIN_FILENO, false); - fd_cloexec(STDOUT_FILENO, false); - fd_nonblock(STDIN_FILENO, false); - fd_nonblock(STDOUT_FILENO, false); - - if (b->exec_argv) - execvp(b->exec_path, b->exec_argv); - else { - const char *argv[] = { b->exec_path, NULL }; - execvp(b->exec_path, (char**) argv); - } - - _exit(EXIT_FAILURE); - } - - close_nointr_nofail(s[1]); - b->output_fd = b->input_fd = s[0]; - - bus_socket_setup(b); - - return bus_socket_start_auth(b); -} - -int bus_socket_take_fd(sd_bus *b) { - assert(b); - - bus_socket_setup(b); - - return bus_socket_start_auth(b); -} - -int bus_socket_write_message(sd_bus *bus, sd_bus_message *m, size_t *idx) { - struct iovec *iov; - ssize_t k; - size_t n; - unsigned j; - int r; - - assert(bus); - assert(m); - assert(idx); - assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); - - if (*idx >= BUS_MESSAGE_SIZE(m)) - return 0; - - r = bus_message_setup_iovec(m); - if (r < 0) - return r; - - n = m->n_iovec * sizeof(struct iovec); - iov = alloca(n); - memcpy(iov, m->iovec, n); - - j = 0; - iovec_advance(iov, &j, *idx); - - if (bus->prefer_writev) - k = writev(bus->output_fd, iov, m->n_iovec); - else { - struct msghdr mh; - zero(mh); - - if (m->n_fds > 0) { - struct cmsghdr *control; - control = alloca(CMSG_SPACE(sizeof(int) * m->n_fds)); - - mh.msg_control = control; - control->cmsg_level = SOL_SOCKET; - control->cmsg_type = SCM_RIGHTS; - mh.msg_controllen = control->cmsg_len = CMSG_LEN(sizeof(int) * m->n_fds); - memcpy(CMSG_DATA(control), m->fds, sizeof(int) * m->n_fds); - } - - mh.msg_iov = iov; - mh.msg_iovlen = m->n_iovec; - - k = sendmsg(bus->output_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL); - if (k < 0 && errno == ENOTSOCK) { - bus->prefer_writev = true; - k = writev(bus->output_fd, iov, m->n_iovec); - } - } - - if (k < 0) - return errno == EAGAIN ? 0 : -errno; - - *idx += (size_t) k; - return 1; -} - -static int bus_socket_read_message_need(sd_bus *bus, size_t *need) { - uint32_t a, b; - uint8_t e; - uint64_t sum; - - assert(bus); - assert(need); - assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); - - if (bus->rbuffer_size < sizeof(struct bus_header)) { - *need = sizeof(struct bus_header) + 8; - - /* Minimum message size: - * - * Header + - * - * Method Call: +2 string headers - * Signal: +3 string headers - * Method Error: +1 string headers - * +1 uint32 headers - * Method Reply: +1 uint32 headers - * - * A string header is at least 9 bytes - * A uint32 header is at least 8 bytes - * - * Hence the minimum message size of a valid message - * is header + 8 bytes */ - - return 0; - } - - a = ((const uint32_t*) bus->rbuffer)[1]; - b = ((const uint32_t*) bus->rbuffer)[3]; - - e = ((const uint8_t*) bus->rbuffer)[0]; - if (e == BUS_LITTLE_ENDIAN) { - a = le32toh(a); - b = le32toh(b); - } else if (e == BUS_BIG_ENDIAN) { - a = be32toh(a); - b = be32toh(b); - } else - return -EBADMSG; - - sum = (uint64_t) sizeof(struct bus_header) + (uint64_t) ALIGN_TO(b, 8) + (uint64_t) a; - if (sum >= BUS_MESSAGE_SIZE_MAX) - return -ENOBUFS; - - *need = (size_t) sum; - return 0; -} - -static int bus_socket_make_message(sd_bus *bus, size_t size) { - sd_bus_message *t; - void *b; - int r; - - assert(bus); - assert(bus->rbuffer_size >= size); - assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); - - r = bus_rqueue_make_room(bus); - if (r < 0) - return r; - - if (bus->rbuffer_size > size) { - b = memdup((const uint8_t*) bus->rbuffer + size, - bus->rbuffer_size - size); - if (!b) - return -ENOMEM; - } else - b = NULL; - - r = bus_message_from_malloc(bus, - bus->rbuffer, size, - bus->fds, bus->n_fds, - !bus->bus_client && bus->ucred_valid ? &bus->ucred : NULL, - !bus->bus_client && bus->label[0] ? bus->label : NULL, - &t); - if (r < 0) { - free(b); - return r; - } - - bus->rbuffer = b; - bus->rbuffer_size -= size; - - bus->fds = NULL; - bus->n_fds = 0; - - bus->rqueue[bus->rqueue_size++] = t; - - return 1; -} - -int bus_socket_read_message(sd_bus *bus) { - struct msghdr mh; - struct iovec iov; - ssize_t k; - size_t need; - int r; - void *b; - union { - struct cmsghdr cmsghdr; - uint8_t buf[CMSG_SPACE(sizeof(int) * BUS_FDS_MAX) + - CMSG_SPACE(sizeof(struct ucred)) + - CMSG_SPACE(NAME_MAX)]; /*selinux label */ - } control; - struct cmsghdr *cmsg; - bool handle_cmsg = false; - - assert(bus); - assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO); - - r = bus_socket_read_message_need(bus, &need); - if (r < 0) - return r; - - if (bus->rbuffer_size >= need) - return bus_socket_make_message(bus, need); - - b = realloc(bus->rbuffer, need); - if (!b) - return -ENOMEM; - - bus->rbuffer = b; - - zero(iov); - iov.iov_base = (uint8_t*) bus->rbuffer + bus->rbuffer_size; - iov.iov_len = need - bus->rbuffer_size; - - if (bus->prefer_readv) - k = readv(bus->input_fd, &iov, 1); - else { - zero(mh); - mh.msg_iov = &iov; - mh.msg_iovlen = 1; - mh.msg_control = &control; - mh.msg_controllen = sizeof(control); - - k = recvmsg(bus->input_fd, &mh, MSG_DONTWAIT|MSG_NOSIGNAL|MSG_CMSG_CLOEXEC); - if (k < 0 && errno == ENOTSOCK) { - bus->prefer_readv = true; - k = readv(bus->input_fd, &iov, 1); - } else - handle_cmsg = true; - } - if (k < 0) - return errno == EAGAIN ? 0 : -errno; - if (k == 0) - return -ECONNRESET; - - bus->rbuffer_size += k; - - if (handle_cmsg) { - for (cmsg = CMSG_FIRSTHDR(&mh); cmsg; cmsg = CMSG_NXTHDR(&mh, cmsg)) { - if (cmsg->cmsg_level == SOL_SOCKET && - cmsg->cmsg_type == SCM_RIGHTS) { - int n, *f; - - n = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int); - - if (!bus->can_fds) { - /* Whut? We received fds but this - * isn't actually enabled? Close them, - * and fail */ - - close_many((int*) CMSG_DATA(cmsg), n); - return -EIO; - } - - f = realloc(bus->fds, sizeof(int) + (bus->n_fds + n)); - if (!f) { - close_many((int*) CMSG_DATA(cmsg), n); - return -ENOMEM; - } - - memcpy(f + bus->n_fds, CMSG_DATA(cmsg), n * sizeof(int)); - bus->fds = f; - bus->n_fds += n; - } else if (cmsg->cmsg_level == SOL_SOCKET && - cmsg->cmsg_type == SCM_CREDENTIALS && - cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) { - - /* Ignore bogus data, which we might - * get on socketpair() sockets */ - if (((struct ucred*) CMSG_DATA(cmsg))->pid != 0) { - memcpy(&bus->ucred, CMSG_DATA(cmsg), sizeof(struct ucred)); - bus->ucred_valid = true; - } - - } else if (cmsg->cmsg_level == SOL_SOCKET && - cmsg->cmsg_type == SCM_SECURITY) { - - size_t l; - l = cmsg->cmsg_len - CMSG_LEN(0); - if (l > 0) { - memcpy(&bus->label, CMSG_DATA(cmsg), l); - bus->label[l] = 0; - } - } - } - } - - r = bus_socket_read_message_need(bus, &need); - if (r < 0) - return r; - - if (bus->rbuffer_size >= need) - return bus_socket_make_message(bus, need); - - return 1; -} - -int bus_socket_process_opening(sd_bus *b) { - int error = 0; - socklen_t slen = sizeof(error); - struct pollfd p = { - .fd = b->output_fd, - .events = POLLOUT, - }; - int r; - - assert(b->state == BUS_OPENING); - - r = poll(&p, 1, 0); - if (r < 0) - return -errno; - - if (!(p.revents & (POLLOUT|POLLERR|POLLHUP))) - return 0; - - r = getsockopt(b->output_fd, SOL_SOCKET, SO_ERROR, &error, &slen); - if (r < 0) - b->last_connect_error = errno; - else if (error != 0) - b->last_connect_error = error; - else if (p.revents & (POLLERR|POLLHUP)) - b->last_connect_error = ECONNREFUSED; - else - return bus_socket_start_auth(b); - - return bus_next_address(b); -} - -int bus_socket_process_authenticating(sd_bus *b) { - int r; - - assert(b); - assert(b->state == BUS_AUTHENTICATING); - - if (now(CLOCK_MONOTONIC) >= b->auth_timeout) - return -ETIMEDOUT; - - r = bus_socket_write_auth(b); - if (r != 0) - return r; - - return bus_socket_read_auth(b); -}