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-rw-r--r--src/ask-password.c352
1 files changed, 352 insertions, 0 deletions
diff --git a/src/ask-password.c b/src/ask-password.c
new file mode 100644
index 0000000000..2c9b027d00
--- /dev/null
+++ b/src/ask-password.c
@@ -0,0 +1,352 @@
+/*-*- 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 General Public License as published by
+ the Free Software Foundation; either version 2 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
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <sys/socket.h>
+#include <sys/poll.h>
+#include <sys/types.h>
+#include <assert.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/un.h>
+#include <sys/stat.h>
+#include <sys/signalfd.h>
+#include <getopt.h>
+
+#include "log.h"
+#include "macro.h"
+#include "util.h"
+
+static const char *arg_icon = NULL;
+static const char *arg_message = NULL;
+static usec_t arg_timeout = 60 * USEC_PER_SEC;
+
+static int create_socket(char **name) {
+ int fd;
+ union {
+ struct sockaddr sa;
+ struct sockaddr_un un;
+ } sa;
+ int one = 1, r;
+ char *c;
+
+ assert(name);
+
+ if ((fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0)) < 0) {
+ log_error("socket() failed: %m");
+ return -errno;
+ }
+
+ zero(sa);
+ sa.un.sun_family = AF_UNIX;
+ snprintf(sa.un.sun_path+1, sizeof(sa.un.sun_path)-1, "/org/freedesktop/systemd1/ask-password/%llu", random_ull());
+
+ if (bind(fd, &sa.sa, sizeof(sa_family_t) + 1 + strlen(sa.un.sun_path+1)) < 0) {
+ r = -errno;
+ log_error("bind() failed: %m");
+ goto fail;
+ }
+
+ if (setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one)) < 0) {
+ r = -errno;
+ log_error("SO_PASSCRED failed: %m");
+ goto fail;
+ }
+
+ if (!(c = strdup(sa.un.sun_path+1))) {
+ r = -ENOMEM;
+ log_error("Out of memory");
+ goto fail;
+ }
+
+ *name = c;
+ return fd;
+
+fail:
+ close_nointr_nofail(fd);
+
+ return r;
+}
+
+static int help(void) {
+
+ printf("%s [OPTIONS...] MESSAGE\n\n"
+ "Query the user for a passphrase.\n\n"
+ " -h --help Show this help\n"
+ " --icon=NAME Icon name\n"
+ " --timeout=USEC Timeout in usec\n",
+ program_invocation_short_name);
+
+ return 0;
+}
+
+static int parse_argv(int argc, char *argv[]) {
+
+ enum {
+ ARG_ICON = 0x100,
+ ARG_TIMEOUT
+ };
+
+ static const struct option options[] = {
+ { "help", no_argument, NULL, 'h' },
+ { "icon", required_argument, NULL, ARG_ICON },
+ { "timeout", required_argument, NULL, ARG_TIMEOUT },
+ { NULL, 0, NULL, 0 }
+ };
+
+ int c;
+
+ assert(argc >= 0);
+ assert(argv);
+
+ while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0) {
+
+ switch (c) {
+
+ case 'h':
+ help();
+ return 0;
+
+ case ARG_ICON:
+ arg_icon = optarg;
+ break;
+
+ case ARG_TIMEOUT:
+ if (parse_usec(optarg, &arg_timeout) < 0 || arg_timeout <= 0) {
+ log_error("Failed to parse --timeout parameter %s", optarg);
+ return -EINVAL;
+ }
+ break;
+
+ case '?':
+ return -EINVAL;
+
+ default:
+ log_error("Unknown option code %c", c);
+ return -EINVAL;
+ }
+ }
+
+ if (optind != argc-1) {
+ help();
+ return -EINVAL;
+ }
+
+ arg_message = argv[optind];
+ return 0;
+}
+
+int main(int argc, char *argv[]) {
+ char temp[] = "/dev/.systemd/ask-password/tmp.XXXXXX";
+ char final[sizeof(temp)] = "";
+ int fd = -1, r = EXIT_FAILURE, k;
+ FILE *f = NULL;
+ char *socket_name = NULL;
+ int socket_fd, signal_fd;
+ sigset_t mask;
+ usec_t not_after;
+
+ log_parse_environment();
+ log_open();
+
+ if ((k = parse_argv(argc, argv)) < 0) {
+ r = k < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
+ goto finish;
+ }
+
+ if ((fd = mkostemp(temp, O_CLOEXEC|O_CREAT|O_WRONLY)) < 0) {
+ log_error("Failed to create password file: %m");
+ goto finish;
+ }
+
+ fchmod(fd, 0644);
+
+ if (!(f = fdopen(fd, "w"))) {
+ log_error("Failed to allocate FILE: %m");
+ goto finish;
+ }
+
+ fd = -1;
+
+ assert_se(sigemptyset(&mask) == 0);
+ sigset_add_many(&mask, SIGINT, SIGTERM, -1);
+ assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
+
+ if ((signal_fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0) {
+ log_error("signalfd(): %m");
+ goto finish;
+ }
+
+ if ((socket_fd = create_socket(&socket_name)) < 0)
+ goto finish;
+
+ not_after = now(CLOCK_MONOTONIC) + arg_timeout;
+
+ fprintf(f,
+ "[Ask]\n"
+ "Socket=%s\n"
+ "NotAfter=%llu\n",
+ socket_name,
+ (unsigned long long) not_after);
+
+ if (arg_message)
+ fprintf(f, "Message=%s\n", arg_message);
+
+ if (arg_icon)
+ fprintf(f, "Icon=%s\n", arg_icon);
+
+ fflush(f);
+
+ if (ferror(f)) {
+ log_error("Failed to write query file: %m");
+ goto finish;
+ }
+
+ memcpy(final, temp, sizeof(temp));
+
+ final[sizeof(final)-11] = 'a';
+ final[sizeof(final)-10] = 's';
+ final[sizeof(final)-9] = 'k';
+
+ if (rename(temp, final) < 0) {
+ log_error("Failed to rename query file: %m");
+ goto finish;
+ }
+
+ for (;;) {
+ enum {
+ FD_SOCKET,
+ FD_SIGNAL,
+ _FD_MAX
+ };
+
+ char passphrase[LINE_MAX+1];
+ struct msghdr msghdr;
+ struct iovec iovec;
+ struct ucred *ucred;
+ union {
+ struct cmsghdr cmsghdr;
+ uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
+ } control;
+ ssize_t n;
+ struct pollfd pollfd[_FD_MAX];
+
+ zero(pollfd);
+ pollfd[FD_SOCKET].fd = socket_fd;
+ pollfd[FD_SOCKET].events = POLLIN;
+ pollfd[FD_SIGNAL].fd = signal_fd;
+ pollfd[FD_SIGNAL].events = POLLIN;
+
+ if ((k = poll(pollfd, 2, arg_timeout/USEC_PER_MSEC)) < 0) {
+
+ if (errno == EINTR)
+ continue;
+
+ log_error("poll() failed: %s", strerror(-r));
+ goto finish;
+ }
+
+ if (k <= 0) {
+ log_notice("Timed out");
+ goto finish;
+ }
+
+ if (pollfd[FD_SIGNAL].revents & POLLIN)
+ break;
+
+ if (pollfd[FD_SOCKET].revents != POLLIN) {
+ log_error("Unexpected poll() event.");
+ goto finish;
+ }
+
+ zero(iovec);
+ iovec.iov_base = passphrase;
+ iovec.iov_len = sizeof(passphrase)-1;
+
+ zero(control);
+ zero(msghdr);
+ msghdr.msg_iov = &iovec;
+ msghdr.msg_iovlen = 1;
+ msghdr.msg_control = &control;
+ msghdr.msg_controllen = sizeof(control);
+
+ if ((n = recvmsg(socket_fd, &msghdr, 0)) < 0) {
+
+ if (errno == EAGAIN ||
+ errno == EINTR)
+ continue;
+
+ log_error("recvmsg() failed: %m");
+ goto finish;
+ }
+
+ if (n <= 0) {
+ log_error("Message too short");
+ continue;
+ }
+
+ if (msghdr.msg_controllen < CMSG_LEN(sizeof(struct ucred)) ||
+ control.cmsghdr.cmsg_level != SOL_SOCKET ||
+ control.cmsghdr.cmsg_type != SCM_CREDENTIALS ||
+ control.cmsghdr.cmsg_len != CMSG_LEN(sizeof(struct ucred))) {
+ log_warning("Received message without credentials. Ignoring.");
+ continue;
+ }
+
+ ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr);
+ if (ucred->uid != 0) {
+ log_warning("Got request from unprivileged user. Ignoring.");
+ continue;
+ }
+
+ if (passphrase[0] == '+') {
+ passphrase[n] = 0;
+ fputs(passphrase+1, stdout);
+ } else if (passphrase[0] == '-')
+ goto finish;
+ else {
+ log_error("Invalid packet");
+ continue;
+ }
+
+ break;
+ }
+
+ r = EXIT_SUCCESS;
+
+finish:
+ if (fd >= 0)
+ close_nointr_nofail(fd);
+
+ if (socket_fd >= 0)
+ close_nointr_nofail(socket_fd);
+
+ if (f)
+ fclose(f);
+
+ unlink(temp);
+
+ if (final[0])
+ unlink(final);
+
+ return r;
+}