| /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
| |
| /*** |
| This file is part of systemd. |
| |
| Copyright 2010 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 <sys/types.h> |
| #include <fcntl.h> |
| #include <unistd.h> |
| #include <string.h> |
| #include <errno.h> |
| #include <sys/epoll.h> |
| #include <stddef.h> |
| |
| #include "log.h" |
| #include "util.h" |
| #include "socket-util.h" |
| |
| #define BUFFER_SIZE (64*1024) |
| #define EXTRA_SIZE 16 |
| |
| static bool initial_nul = false; |
| static bool auth_over = false; |
| |
| static void format_uid(char *buf, size_t l) { |
| char text[20 + 1]; /* enough space for a 64bit integer plus NUL */ |
| unsigned j; |
| |
| assert(l > 0); |
| |
| snprintf(text, sizeof(text)-1, "%llu", (unsigned long long) geteuid()); |
| text[sizeof(text)-1] = 0; |
| |
| memset(buf, 0, l); |
| |
| for (j = 0; text[j] && j*2+2 < l; j++) { |
| buf[j*2] = hexchar(text[j] >> 4); |
| buf[j*2+1] = hexchar(text[j] & 0xF); |
| } |
| |
| buf[j*2] = 0; |
| } |
| |
| static size_t patch_in_line(char *line, size_t l, size_t left) { |
| size_t r; |
| |
| if (line[0] == 0 && !initial_nul) { |
| initial_nul = true; |
| line += 1; |
| l -= 1; |
| r = 1; |
| } else |
| r = 0; |
| |
| if (l == 5 && strneq(line, "BEGIN", 5)) { |
| r += l; |
| auth_over = true; |
| |
| } else if (l == 17 && strneq(line, "NEGOTIATE_UNIX_FD", 17)) { |
| memmove(line + 13, line + 17, left); |
| memcpy(line, "NEGOTIATE_NOP", 13); |
| r += 13; |
| |
| } else if (l >= 14 && strneq(line, "AUTH EXTERNAL ", 14)) { |
| char uid[20*2 + 1]; |
| size_t len; |
| |
| format_uid(uid, sizeof(uid)); |
| len = strlen(uid); |
| assert(len <= EXTRA_SIZE); |
| |
| memmove(line + 14 + len, line + l, left); |
| memcpy(line + 14, uid, len); |
| |
| r += 14 + len; |
| } else |
| r += l; |
| |
| return r; |
| } |
| |
| static size_t patch_in_buffer(char* in_buffer, size_t *in_buffer_full) { |
| size_t i, good = 0; |
| |
| if (*in_buffer_full <= 0) |
| return *in_buffer_full; |
| |
| /* If authentication is done, we don't touch anything anymore */ |
| if (auth_over) |
| return *in_buffer_full; |
| |
| if (*in_buffer_full < 2) |
| return 0; |
| |
| for (i = 0; i <= *in_buffer_full - 2; i ++) { |
| |
| /* Fully lines can be send on */ |
| if (in_buffer[i] == '\r' && in_buffer[i+1] == '\n') { |
| if (i > good) { |
| size_t old_length, new_length; |
| |
| old_length = i - good; |
| new_length = patch_in_line(in_buffer+good, old_length, *in_buffer_full - i); |
| *in_buffer_full = *in_buffer_full + new_length - old_length; |
| |
| good += new_length + 2; |
| |
| } else |
| good = i+2; |
| } |
| |
| if (auth_over) |
| break; |
| } |
| |
| return good; |
| } |
| |
| int main(int argc, char *argv[]) { |
| int r = EXIT_FAILURE, fd = -1, ep = -1; |
| union sockaddr_union sa; |
| char in_buffer[BUFFER_SIZE+EXTRA_SIZE], out_buffer[BUFFER_SIZE+EXTRA_SIZE]; |
| size_t in_buffer_full = 0, out_buffer_full = 0; |
| struct epoll_event stdin_ev, stdout_ev, fd_ev; |
| bool stdin_readable = false, stdout_writable = false, fd_readable = false, fd_writable = false; |
| bool stdin_rhup = false, stdout_whup = false, fd_rhup = false, fd_whup = false; |
| |
| if (argc > 1) { |
| log_error("This program takes no argument."); |
| return EXIT_FAILURE; |
| } |
| |
| log_set_target(LOG_TARGET_JOURNAL_OR_KMSG); |
| log_parse_environment(); |
| log_open(); |
| |
| if ((fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0)) < 0) { |
| log_error("Failed to create socket: %s", strerror(errno)); |
| goto finish; |
| } |
| |
| zero(sa); |
| sa.un.sun_family = AF_UNIX; |
| strncpy(sa.un.sun_path, "/run/dbus/system_bus_socket", sizeof(sa.un.sun_path)); |
| |
| if (connect(fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + strlen(sa.un.sun_path)) < 0) { |
| log_error("Failed to connect: %m"); |
| goto finish; |
| } |
| |
| fd_nonblock(STDIN_FILENO, 1); |
| fd_nonblock(STDOUT_FILENO, 1); |
| |
| if ((ep = epoll_create1(EPOLL_CLOEXEC)) < 0) { |
| log_error("Failed to create epoll: %m"); |
| goto finish; |
| } |
| |
| zero(stdin_ev); |
| stdin_ev.events = EPOLLIN|EPOLLET; |
| stdin_ev.data.fd = STDIN_FILENO; |
| |
| zero(stdout_ev); |
| stdout_ev.events = EPOLLOUT|EPOLLET; |
| stdout_ev.data.fd = STDOUT_FILENO; |
| |
| zero(fd_ev); |
| fd_ev.events = EPOLLIN|EPOLLOUT|EPOLLET; |
| fd_ev.data.fd = fd; |
| |
| if (epoll_ctl(ep, EPOLL_CTL_ADD, STDIN_FILENO, &stdin_ev) < 0 || |
| epoll_ctl(ep, EPOLL_CTL_ADD, STDOUT_FILENO, &stdout_ev) < 0 || |
| epoll_ctl(ep, EPOLL_CTL_ADD, fd, &fd_ev) < 0) { |
| log_error("Failed to regiser fds in epoll: %m"); |
| goto finish; |
| } |
| |
| do { |
| struct epoll_event ev[16]; |
| ssize_t k; |
| int i, nfds; |
| |
| if ((nfds = epoll_wait(ep, ev, ELEMENTSOF(ev), -1)) < 0) { |
| |
| if (errno == EINTR || errno == EAGAIN) |
| continue; |
| |
| log_error("epoll_wait(): %m"); |
| goto finish; |
| } |
| |
| assert(nfds >= 1); |
| |
| for (i = 0; i < nfds; i++) { |
| if (ev[i].data.fd == STDIN_FILENO) { |
| |
| if (!stdin_rhup && (ev[i].events & (EPOLLHUP|EPOLLIN))) |
| stdin_readable = true; |
| |
| } else if (ev[i].data.fd == STDOUT_FILENO) { |
| |
| if (ev[i].events & EPOLLHUP) { |
| stdout_writable = false; |
| stdout_whup = true; |
| } |
| |
| if (!stdout_whup && (ev[i].events & EPOLLOUT)) |
| stdout_writable = true; |
| |
| } else if (ev[i].data.fd == fd) { |
| |
| if (ev[i].events & EPOLLHUP) { |
| fd_writable = false; |
| fd_whup = true; |
| } |
| |
| if (!fd_rhup && (ev[i].events & (EPOLLHUP|EPOLLIN))) |
| fd_readable = true; |
| |
| if (!fd_whup && (ev[i].events & EPOLLOUT)) |
| fd_writable = true; |
| } |
| } |
| |
| while ((stdin_readable && in_buffer_full <= 0) || |
| (fd_writable && patch_in_buffer(in_buffer, &in_buffer_full) > 0) || |
| (fd_readable && out_buffer_full <= 0) || |
| (stdout_writable && out_buffer_full > 0)) { |
| |
| size_t in_buffer_good = 0; |
| |
| if (stdin_readable && in_buffer_full < BUFFER_SIZE) { |
| |
| if ((k = read(STDIN_FILENO, in_buffer + in_buffer_full, BUFFER_SIZE - in_buffer_full)) < 0) { |
| |
| if (errno == EAGAIN) |
| stdin_readable = false; |
| else if (errno == EPIPE || errno == ECONNRESET) |
| k = 0; |
| else { |
| log_error("read(): %m"); |
| goto finish; |
| } |
| } else |
| in_buffer_full += (size_t) k; |
| |
| if (k == 0) { |
| stdin_rhup = true; |
| stdin_readable = false; |
| shutdown(STDIN_FILENO, SHUT_RD); |
| close_nointr_nofail(STDIN_FILENO); |
| } |
| } |
| |
| in_buffer_good = patch_in_buffer(in_buffer, &in_buffer_full); |
| |
| if (fd_writable && in_buffer_good > 0) { |
| |
| if ((k = write(fd, in_buffer, in_buffer_good)) < 0) { |
| |
| if (errno == EAGAIN) |
| fd_writable = false; |
| else if (errno == EPIPE || errno == ECONNRESET) { |
| fd_whup = true; |
| fd_writable = false; |
| shutdown(fd, SHUT_WR); |
| } else { |
| log_error("write(): %m"); |
| goto finish; |
| } |
| |
| } else { |
| assert(in_buffer_full >= (size_t) k); |
| memmove(in_buffer, in_buffer + k, in_buffer_full - k); |
| in_buffer_full -= k; |
| } |
| } |
| |
| if (fd_readable && out_buffer_full < BUFFER_SIZE) { |
| |
| if ((k = read(fd, out_buffer + out_buffer_full, BUFFER_SIZE - out_buffer_full)) < 0) { |
| |
| if (errno == EAGAIN) |
| fd_readable = false; |
| else if (errno == EPIPE || errno == ECONNRESET) |
| k = 0; |
| else { |
| log_error("read(): %m"); |
| goto finish; |
| } |
| } else |
| out_buffer_full += (size_t) k; |
| |
| if (k == 0) { |
| fd_rhup = true; |
| fd_readable = false; |
| shutdown(fd, SHUT_RD); |
| } |
| } |
| |
| if (stdout_writable && out_buffer_full > 0) { |
| |
| if ((k = write(STDOUT_FILENO, out_buffer, out_buffer_full)) < 0) { |
| |
| if (errno == EAGAIN) |
| stdout_writable = false; |
| else if (errno == EPIPE || errno == ECONNRESET) { |
| stdout_whup = true; |
| stdout_writable = false; |
| shutdown(STDOUT_FILENO, SHUT_WR); |
| close_nointr(STDOUT_FILENO); |
| } else { |
| log_error("write(): %m"); |
| goto finish; |
| } |
| |
| } else { |
| assert(out_buffer_full >= (size_t) k); |
| memmove(out_buffer, out_buffer + k, out_buffer_full - k); |
| out_buffer_full -= k; |
| } |
| } |
| } |
| |
| if (stdin_rhup && in_buffer_full <= 0 && !fd_whup) { |
| fd_whup = true; |
| fd_writable = false; |
| shutdown(fd, SHUT_WR); |
| } |
| |
| if (fd_rhup && out_buffer_full <= 0 && !stdout_whup) { |
| stdout_whup = true; |
| stdout_writable = false; |
| shutdown(STDOUT_FILENO, SHUT_WR); |
| close_nointr(STDOUT_FILENO); |
| } |
| |
| } while (!stdout_whup || !fd_whup); |
| |
| r = EXIT_SUCCESS; |
| |
| finish: |
| if (fd >= 0) |
| close_nointr_nofail(fd); |
| |
| if (ep >= 0) |
| close_nointr_nofail(ep); |
| |
| return r; |
| } |