2 * Copyright (C) 1997-2013 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file command.c Client authentication and server commands. */
12 #include <sys/types.h>
20 #include "server.cmdline.h"
33 #include "user_list.h"
34 #include "server_command_list.h"
35 #include "afs_command_list.h"
39 struct server_command afs_cmds[] = {DEFINE_AFS_CMD_ARRAY};
40 struct server_command server_cmds[] = {DEFINE_SERVER_CMD_ARRAY};
42 /** Commands including options must be shorter than this. */
43 #define MAX_COMMAND_LEN 32768
46 extern struct misc_meta_data *mmd;
47 extern struct sender senders[];
48 int send_afs_status(struct command_context *cc, int parser_friendly);
50 static void dummy(__a_unused int s)
54 static void mmd_dup(struct misc_meta_data *new_mmd)
56 mutex_lock(mmd_mutex);
58 mutex_unlock(mmd_mutex);
62 * Compute human readable string containing vss status for given integer value.
64 * We don't want to use vss_playing() and friends here because we take a
65 * snapshot of the mmd struct and use the copy for computing the state of the
66 * vss. If the real data were used, we would take the mmd lock for a rather
67 * long time or risk to get an inconsistent view.
69 static char *vss_status_tohuman(unsigned int flags)
71 if (flags & VSS_PLAYING)
72 return para_strdup("playing");
74 return para_strdup("stopped");
75 return para_strdup("paused");
79 * return human readable permission string. Never returns NULL.
81 static char *cmd_perms_itohuman(unsigned int perms)
83 char *msg = para_malloc(5 * sizeof(char));
85 msg[0] = perms & AFS_READ? 'a' : '-';
86 msg[1] = perms & AFS_WRITE? 'A' : '-';
87 msg[2] = perms & VSS_READ? 'v' : '-';
88 msg[3] = perms & VSS_WRITE? 'V' : '-';
96 static char *vss_get_status_flags(unsigned int flags)
98 char *msg = para_malloc(5 * sizeof(char));
100 msg[0] = (flags & VSS_PLAYING)? 'P' : '_';
101 msg[1] = (flags & VSS_NOMORE)? 'O' : '_';
102 msg[2] = (flags & VSS_NEXT)? 'N' : '_';
103 msg[3] = (flags & VSS_REPOS)? 'R' : '_';
108 static unsigned get_status(struct misc_meta_data *nmmd, int parser_friendly,
112 char *status, *flags; /* vss status info */
113 /* nobody updates our version of "now" */
114 char *ut = get_server_uptime_str(NULL);
115 long offset = (nmmd->offset + 500) / 1000;
116 struct timeval current_time;
118 struct para_buffer b = {.flags = parser_friendly? PBF_SIZE_PREFIX : 0};
120 /* report real status */
121 status = vss_status_tohuman(nmmd->vss_status_flags);
122 flags = vss_get_status_flags(nmmd->vss_status_flags);
123 if (nmmd->size) { /* parent currently has an audio file open */
124 localtime_r(&nmmd->mtime, &mtime_tm);
125 strftime(mtime, 29, "%b %d %Y", &mtime_tm);
127 gettimeofday(¤t_time, NULL);
129 * The calls to WRITE_STATUS_ITEM() below never fail because
130 * b->max_size is zero (unlimited), see para_printf(). However, clang
131 * is not smart enough to prove this and complains nevertheless.
132 * Casting the return value to void silences clang.
134 (void)WRITE_STATUS_ITEM(&b, SI_FILE_SIZE, "%zu\n", nmmd->size / 1024);
135 (void)WRITE_STATUS_ITEM(&b, SI_MTIME, "%s\n", mtime);
136 (void)WRITE_STATUS_ITEM(&b, SI_STATUS, "%s\n", status);
137 (void)WRITE_STATUS_ITEM(&b, SI_STATUS_FLAGS, "%s\n", flags);
138 (void)WRITE_STATUS_ITEM(&b, SI_OFFSET, "%li\n", offset);
139 (void)WRITE_STATUS_ITEM(&b, SI_AFS_MODE, "%s\n", mmd->afs_mode_string);
140 (void)WRITE_STATUS_ITEM(&b, SI_STREAM_START, "%lu.%lu\n",
141 (long unsigned)nmmd->stream_start.tv_sec,
142 (long unsigned)nmmd->stream_start.tv_usec);
143 (void)WRITE_STATUS_ITEM(&b, SI_CURRENT_TIME, "%lu.%lu\n",
144 (long unsigned)current_time.tv_sec,
145 (long unsigned)current_time.tv_usec);
153 static int check_sender_args(int argc, char * const * argv, struct sender_command_data *scd)
156 /* this has to match sender.h */
157 const char *subcmds[] = {"add", "delete", "allow", "deny", "on", "off", NULL};
159 scd->sender_num = -1;
161 return -E_COMMAND_SYNTAX;
162 for (i = 0; senders[i].name; i++)
163 if (!strcmp(senders[i].name, argv[1]))
165 PARA_DEBUG_LOG("%d:%s\n", argc, argv[1]);
166 if (!senders[i].name)
167 return -E_COMMAND_SYNTAX;
169 for (i = 0; subcmds[i]; i++)
170 if (!strcmp(subcmds[i], argv[2]))
173 return -E_COMMAND_SYNTAX;
175 if (!senders[scd->sender_num].client_cmds[scd->cmd_num])
176 return -E_SENDER_CMD;
177 switch (scd->cmd_num) {
181 return -E_COMMAND_SYNTAX;
185 if (argc != 4 || parse_cidr(argv[3], scd->host,
186 sizeof(scd->host), &scd->netmask) == NULL)
187 return -E_COMMAND_SYNTAX;
192 return -E_COMMAND_SYNTAX;
193 return parse_fec_url(argv[3], scd);
195 return -E_COMMAND_SYNTAX;
201 * Send a sideband packet through a blocking file descriptor.
203 * \param scc fd and crypto keys.
204 * \param buf The buffer to send.
205 * \param numbytes The size of \a buf.
206 * \param band The sideband designator of this packet.
207 * \param dont_free If true, never deallocate \a buf.
209 * The nonblock flag must be disabled for the file descriptor given by \a scc.
211 * Stream cipher encryption is automatically activated if neccessary via the
212 * sideband transformation, depending on the value of \a band.
216 * \sa \ref send_sb_va().
218 int send_sb(struct stream_cipher_context *scc, void *buf, size_t numbytes,
219 int band, bool dont_free)
222 struct sb_context *sbc;
224 struct sb_buffer sbb = SBB_INIT(band, buf, numbytes);
225 sb_transformation trafo = band < SBD_PROCEED? NULL : sc_trafo;
227 sbc = sb_new_send(&sbb, dont_free, trafo, scc->send);
229 ret = sb_get_send_buffers(sbc, iov);
230 ret = xwritev(scc->fd, iov, ret);
233 } while (sb_sent(sbc, ret) == false);
241 * Create a variable sized buffer and send it as a sideband packet.
243 * \param scc Passed to \ref send_sb.
244 * \param band See \ref send_sb.
245 * \param fmt The format string.
247 * \return The return value of the underlying call to \ref send_sb.
249 __printf_3_4 int send_sb_va(struct stream_cipher_context *scc, int band,
250 const char *fmt, ...)
257 ret = xvasprintf(&msg, fmt, ap);
259 return send_sb(scc, msg, ret, band, false);
263 * Send an error message to a client.
265 * \param cc Client info.
266 * \param err The (positive) error code.
268 * \return The return value of the underlying call to send_sb_va().
270 int send_strerror(struct command_context *cc, int err)
272 return cc->use_sideband?
273 send_sb_va(&cc->scc, SBD_ERROR_LOG, "%s\n", para_strerror(err))
275 sc_send_va_buffer(&cc->scc, "%s\n", para_strerror(err));
279 * Send a sideband packet through a blocking file descriptor.
281 * \param scc fd and crypto keys.
282 * \param expected_band The expected band designator.
283 * \param max_size Passed to \ref sb_new_recv().
284 * \param result Body of the sideband packet is returned here.
286 * If \a expected_band is not \p SBD_ANY, the band designator of the received
287 * sideband packet is compared to \a expected_band and a mismatch is considered
292 int recv_sb(struct stream_cipher_context *scc,
293 enum sb_designator expected_band,
294 size_t max_size, struct iovec *result)
297 struct sb_context *sbc;
299 struct sb_buffer sbb;
300 sb_transformation trafo;
302 trafo = expected_band != SBD_ANY && expected_band < SBD_PROCEED?
304 sbc = sb_new_recv(max_size, trafo, scc->recv);
306 sb_get_recv_buffer(sbc, &iov);
307 ret = recv_bin_buffer(scc->fd, iov.iov_base, iov.iov_len);
312 ret = sb_received(sbc, ret, &sbb);
319 if (expected_band != SBD_ANY && sbb.band != expected_band)
328 static int com_sender(struct command_context *cc)
332 struct sender_command_data scd;
335 for (i = 0; senders[i].name; i++) {
337 ret = xasprintf(&tmp, "%s%s\n", msg? msg : "",
342 if (cc->use_sideband)
343 return send_sb(&cc->scc, msg, ret, SBD_OUTPUT, false);
344 ret = sc_send_buffer(&cc->scc, msg);
348 ret = check_sender_args(cc->argc, cc->argv, &scd);
350 if (scd.sender_num < 0)
352 msg = senders[scd.sender_num].help();
353 if (cc->use_sideband)
354 return send_sb(&cc->scc, msg, strlen(msg), SBD_OUTPUT,
356 ret = sc_send_buffer(&cc->scc, msg);
361 switch (scd.cmd_num) {
364 assert(senders[scd.sender_num].resolve_target);
365 ret = senders[scd.sender_num].resolve_target(cc->argv[3], &scd);
370 for (i = 0; i < 10; i++) {
371 mutex_lock(mmd_mutex);
372 if (mmd->sender_cmd_data.cmd_num >= 0) {
373 mutex_unlock(mmd_mutex);
377 memcpy(&mmd->sender_cmd_data, &scd, sizeof(scd));
378 mutex_unlock(mmd_mutex);
381 return (i < 10)? 1 : -E_LOCK;
385 static int com_si(struct command_context *cc)
388 char *msg, *ut, *sender_info = NULL;
391 return -E_COMMAND_SYNTAX;
392 mutex_lock(mmd_mutex);
393 for (i = 0; senders[i].name; i++) {
394 char *info = senders[i].info();
395 sender_info = para_strcat(sender_info, info);
398 ut = get_server_uptime_str(now);
399 ret = xasprintf(&msg, "version: " GIT_VERSION "\n"
400 "up: %s\nplayed: %u\n"
403 "connections (active/accepted/total): %u/%u/%u\n"
404 "current loglevel: %s\n"
405 "supported audio formats: %s\n"
410 mmd->active_connections,
414 AUDIO_FORMAT_HANDLERS,
417 mutex_unlock(mmd_mutex);
420 if (cc->use_sideband)
421 return send_sb(&cc->scc, msg, ret, SBD_OUTPUT, false);
422 ret = sc_send_bin_buffer(&cc->scc, msg, ret);
428 static int com_version(struct command_context *cc)
434 return -E_COMMAND_SYNTAX;
435 msg = VERSION_TEXT("server") "built: " BUILD_DATE "\n" UNAME_RS
436 ", " CC_VERSION "\n";
438 if (cc->use_sideband)
439 return send_sb(&cc->scc, msg, len, SBD_OUTPUT, true);
440 return sc_send_bin_buffer(&cc->scc, msg, len);
443 #define EMPTY_STATUS_ITEMS \
448 ITEM(ATTRIBUTES_BITMAP) \
449 ITEM(ATTRIBUTES_TXT) \
460 ITEM(SECONDS_TOTAL) \
472 * Write a list of audio-file related status items with empty values.
474 * This is used by vss when currently no audio file is open.
476 static unsigned empty_status_items(int parser_friendly, char **result)
485 len = xasprintf(&esi,
486 #define ITEM(x) "0004 %02x:\n"
489 #define ITEM(x) , SI_ ## x
494 len = xasprintf(&esi,
495 #define ITEM(x) "%s:\n"
498 #define ITEM(x) ,status_item_list[SI_ ## x]
506 #undef EMPTY_STATUS_ITEMS
509 static int com_stat(struct command_context *cc)
512 struct misc_meta_data tmp, *nmmd = &tmp;
513 char *s, *esi = NULL;
515 int parser_friendly = 0;
517 para_sigaction(SIGUSR1, dummy);
519 for (i = 1; i < cc->argc; i++) {
520 const char *arg = cc->argv[i];
523 if (!strcmp(arg, "--")) {
527 if (!strncmp(arg, "-n=", 3)) {
528 ret = para_atoi32(arg + 3, &num);
533 if (!strcmp(arg, "-p")) {
537 return -E_COMMAND_SYNTAX;
540 return -E_COMMAND_SYNTAX;
543 ret = get_status(nmmd, parser_friendly, &s);
544 if (cc->use_sideband)
545 ret = send_sb(&cc->scc, s, ret, SBD_OUTPUT, false);
547 ret = sc_send_bin_buffer(&cc->scc, s, ret);
552 if (nmmd->vss_status_flags & VSS_NEXT) {
553 ret = empty_status_items(parser_friendly, &esi);
554 if (cc->use_sideband)
555 ret = send_sb(&cc->scc, esi, ret, SBD_OUTPUT,
558 ret = sc_send_bin_buffer(&cc->scc, esi, ret);
562 send_afs_status(cc, parser_friendly);
564 if (num > 0 && !--num)
567 ret = -E_SERVER_CRASH;
576 static int send_list_of_commands(struct command_context *cc, struct server_command *cmd,
582 for (; cmd->name; cmd++) {
583 char *tmp, *perms = cmd_perms_itohuman(cmd->perms);
584 tmp = make_message("%s\t%s\t%s\t%s\n", cmd->name, handler,
585 perms, cmd->description);
587 msg = para_strcat(msg, tmp);
590 if (cc->use_sideband)
591 return send_sb(&cc->scc, msg, strlen(msg), SBD_OUTPUT, false);
592 ret = sc_send_buffer(&cc->scc, msg);
597 /* returns string that must be freed by the caller */
598 static struct server_command *get_cmd_ptr(const char *name, char **handler)
600 struct server_command *cmd;
602 for (cmd = server_cmds; cmd->name; cmd++)
603 if (!strcmp(cmd->name, name)) {
605 *handler = para_strdup("server"); /* server commands */
608 /* not found, look for commands supported by afs */
609 for (cmd = afs_cmds; cmd->name; cmd++)
610 if (!strcmp(cmd->name, name)) {
612 *handler = para_strdup("afs");
619 static int com_help(struct command_context *cc)
621 struct server_command *cmd;
622 char *perms, *handler, *buf;
626 /* no argument given, print list of commands */
627 if ((ret = send_list_of_commands(cc, server_cmds, "server")) < 0)
629 return send_list_of_commands(cc, afs_cmds, "afs");
631 /* argument given for help */
632 cmd = get_cmd_ptr(cc->argv[1], &handler);
635 perms = cmd_perms_itohuman(cmd->perms);
636 ret = xasprintf(&buf, "%s - %s\n\n"
650 if (cc->use_sideband)
651 return send_sb(&cc->scc, buf, ret, SBD_OUTPUT, false);
652 ret = sc_send_buffer(&cc->scc, buf);
658 static int com_hup(struct command_context *cc)
661 return -E_COMMAND_SYNTAX;
662 kill(getppid(), SIGHUP);
667 static int com_term(struct command_context *cc)
670 return -E_COMMAND_SYNTAX;
671 kill(getppid(), SIGTERM);
675 static int com_play(struct command_context *cc)
678 return -E_COMMAND_SYNTAX;
679 mutex_lock(mmd_mutex);
680 mmd->new_vss_status_flags |= VSS_PLAYING;
681 mmd->new_vss_status_flags &= ~VSS_NOMORE;
682 mutex_unlock(mmd_mutex);
687 static int com_stop(struct command_context *cc)
690 return -E_COMMAND_SYNTAX;
691 mutex_lock(mmd_mutex);
692 mmd->new_vss_status_flags &= ~VSS_PLAYING;
693 mmd->new_vss_status_flags &= ~VSS_REPOS;
694 mmd->new_vss_status_flags |= VSS_NEXT;
695 mutex_unlock(mmd_mutex);
700 static int com_pause(struct command_context *cc)
703 return -E_COMMAND_SYNTAX;
704 mutex_lock(mmd_mutex);
705 if (!vss_paused() && !vss_stopped()) {
707 mmd->new_vss_status_flags &= ~VSS_PLAYING;
708 mmd->new_vss_status_flags &= ~VSS_NEXT;
710 mutex_unlock(mmd_mutex);
715 static int com_next(struct command_context *cc)
718 return -E_COMMAND_SYNTAX;
719 mutex_lock(mmd_mutex);
721 mmd->new_vss_status_flags |= VSS_NEXT;
722 mutex_unlock(mmd_mutex);
727 static int com_nomore(struct command_context *cc)
730 return -E_COMMAND_SYNTAX;
731 mutex_lock(mmd_mutex);
732 if (vss_playing() || vss_paused())
733 mmd->new_vss_status_flags |= VSS_NOMORE;
734 mutex_unlock(mmd_mutex);
739 static int com_ff(struct command_context *cc)
742 int ret, backwards = 0;
747 return -E_COMMAND_SYNTAX;
748 if (!(ret = sscanf(cc->argv[1], "%u%c", &i, &c)))
749 return -E_COMMAND_SYNTAX;
750 if (ret > 1 && c == '-')
751 backwards = 1; /* jmp backwards */
752 mutex_lock(mmd_mutex);
753 ret = -E_NO_AUDIO_FILE;
754 if (!mmd->afd.afhi.chunks_total || !mmd->afd.afhi.seconds_total)
756 promille = (1000 * mmd->current_chunk) / mmd->afd.afhi.chunks_total;
758 promille -= 1000 * i / mmd->afd.afhi.seconds_total;
760 promille += 1000 * i / mmd->afd.afhi.seconds_total;
763 if (promille > 1000) {
764 mmd->new_vss_status_flags |= VSS_NEXT;
767 mmd->repos_request = (mmd->afd.afhi.chunks_total * promille) / 1000;
768 mmd->new_vss_status_flags |= VSS_REPOS;
769 mmd->new_vss_status_flags &= ~VSS_NEXT;
773 mutex_unlock(mmd_mutex);
778 static int com_jmp(struct command_context *cc)
784 return -E_COMMAND_SYNTAX;
785 if (sscanf(cc->argv[1], "%lu", &i) <= 0)
786 return -E_COMMAND_SYNTAX;
787 mutex_lock(mmd_mutex);
788 ret = -E_NO_AUDIO_FILE;
789 if (!mmd->afd.afhi.chunks_total)
793 PARA_INFO_LOG("jumping to %lu%%\n", i);
794 mmd->repos_request = (mmd->afd.afhi.chunks_total * i + 50)/ 100;
795 PARA_INFO_LOG("sent: %lu, offset before jmp: %lu\n",
796 mmd->chunks_sent, mmd->offset);
797 mmd->new_vss_status_flags |= VSS_REPOS;
798 mmd->new_vss_status_flags &= ~VSS_NEXT;
802 mutex_unlock(mmd_mutex);
807 * check if perms are sufficient to exec a command having perms cmd_perms.
808 * Returns 0 if perms are sufficient, -E_PERM otherwise.
810 static int check_perms(unsigned int perms, struct server_command *cmd_ptr)
812 PARA_DEBUG_LOG("checking permissions\n");
813 return (cmd_ptr->perms & perms) < cmd_ptr->perms ? -E_PERM : 0;
817 * Parse first string from *cmd and lookup in table of valid commands.
818 * On error, NULL is returned.
820 static struct server_command *parse_cmd(const char *cmdstr)
825 sscanf(cmdstr, "%200s%n", buf, &n);
829 return get_cmd_ptr(buf, NULL);
832 static int read_command(struct stream_cipher_context *scc, char **result)
836 char *command = NULL;
842 ret = sc_recv_buffer(scc, buf, sizeof(buf));
848 ret = -E_COMMAND_SYNTAX;
849 if (command && numbytes + strlen(command) > MAX_COMMAND_LEN) /* DOS */
851 command = para_strcat(command, buf);
852 p = strstr(command, EOC_MSG);
858 ret = command? 1 : -E_COMMAND_SYNTAX;
868 static void reset_signals(void)
870 para_sigaction(SIGCHLD, SIG_IGN);
871 para_sigaction(SIGINT, SIG_DFL);
872 para_sigaction(SIGTERM, SIG_DFL);
873 para_sigaction(SIGHUP, SIG_DFL);
876 static int parse_auth_request(char *buf, int len, struct user **u,
880 char *p, *username, **features = NULL;
881 size_t auth_rq_len = strlen(AUTH_REQUEST_MSG);
884 *use_sideband = false;
885 if (len < auth_rq_len + 2)
886 return -E_AUTH_REQUEST;
887 if (strncmp(buf, AUTH_REQUEST_MSG, auth_rq_len) != 0)
888 return -E_AUTH_REQUEST;
889 username = buf + auth_rq_len;
890 p = strchr(username, ' ');
894 return -E_AUTH_REQUEST;
897 create_argv(p, ",", &features);
898 for (i = 0; features[i]; i++) {
899 if (strcmp(features[i], "sideband") == 0)
900 *use_sideband = true;
902 ret = -E_BAD_FEATURE;
907 PARA_DEBUG_LOG("received auth request for user %s (sideband = %s)\n",
908 username, *use_sideband? "true" : "false");
909 *u = lookup_user(username);
916 #define HANDSHAKE_BUFSIZE 4096
918 static int parse_sb_command(struct command_context *cc, struct iovec *iov)
924 if (iov->iov_base == NULL || iov->iov_len == 0)
927 p[iov->iov_len - 1] = '\0'; /* just to be sure */
928 cc->cmd = get_cmd_ptr(p, NULL);
931 ret = check_perms(cc->u->perms, cc->cmd);
934 end = iov->iov_base + iov->iov_len;
935 for (i = 0, p = iov->iov_base; p < end; i++)
938 cc->argv = para_malloc((cc->argc + 1) * sizeof(char *));
939 for (i = 0, p = iov->iov_base; p < end; i++) {
940 cc->argv[i] = para_strdup(p);
943 cc->argv[cc->argc] = NULL;
951 * Perform user authentication and execute a command.
953 * \param fd The file descriptor to send output to.
954 * \param peername Identifies the connecting peer.
956 * Whenever para_server accepts an incoming tcp connection on
957 * the port it listens on, it forks and the resulting child
958 * calls this function.
960 * An RSA-based challenge/response is used to authenticate
961 * the peer. It that authentication succeeds, a random
962 * session key is generated and sent back to the peer,
963 * encrypted with its RSA public key. From this point on,
964 * all transfers are crypted with this session key.
966 * Next it is checked if the peer supplied a valid server command or a command
967 * for the audio file selector. If yes, and if the user has sufficient
968 * permissions to execute that command, the function calls the corresponding
969 * command handler which does argument checking and further processing.
971 * In order to cope with a DOS attacks, a timeout is set up
972 * which terminates the function if the connection was not
973 * authenticated when the timeout expires.
975 * \sa alarm(2), crypt.c, crypt.h
977 __noreturn void handle_connect(int fd, const char *peername)
980 unsigned char rand_buf[CHALLENGE_SIZE + 2 * SESSION_KEY_LEN];
981 unsigned char challenge_hash[HASH_SIZE];
982 char *p, *command = NULL, *buf = para_malloc(HANDSHAKE_BUFSIZE) /* must be on the heap */;
984 struct command_context cc_struct = {.peer = peername}, *cc = &cc_struct;
988 /* we need a blocking fd here as recv() might return EAGAIN otherwise. */
989 ret = mark_fd_blocking(fd);
992 /* send Welcome message */
993 ret = write_va_buffer(fd, "This is para_server, version "
994 PACKAGE_VERSION ".\n"
995 "Features: sideband\n"
999 /* recv auth request line */
1000 ret = recv_buffer(fd, buf, HANDSHAKE_BUFSIZE);
1003 ret = parse_auth_request(buf, ret, &cc->u, &cc->use_sideband);
1006 p = buf + strlen(AUTH_REQUEST_MSG);
1007 PARA_DEBUG_LOG("received auth request for user %s\n", p);
1008 cc->u = lookup_user(p);
1010 get_random_bytes_or_die(rand_buf, sizeof(rand_buf));
1011 ret = pub_encrypt(cc->u->pubkey, rand_buf, sizeof(rand_buf),
1012 (unsigned char *)buf);
1018 * We don't want to reveal our user names, so we send a
1019 * challenge to the client even if the user does not exist, and
1020 * fail the authentication later.
1023 get_random_bytes_or_die((unsigned char *)buf, numbytes);
1025 PARA_DEBUG_LOG("sending %u byte challenge + rc4 keys (%zu bytes)\n",
1026 CHALLENGE_SIZE, numbytes);
1027 if (cc->use_sideband) {
1029 ret = send_sb(&cc->scc, buf, numbytes, SBD_CHALLENGE, false);
1033 ret = recv_sb(&cc->scc, SBD_CHALLENGE_RESPONSE,
1034 HANDSHAKE_BUFSIZE, &iov);
1038 numbytes = iov.iov_len;
1040 ret = write_all(fd, buf, numbytes);
1043 /* recv challenge response */
1044 ret = recv_bin_buffer(fd, buf, HASH_SIZE);
1049 PARA_DEBUG_LOG("received %zu bytes challenge response\n", numbytes);
1054 * The correct response is the hash of the first CHALLENGE_SIZE bytes
1055 * of the random data.
1058 if (numbytes != HASH_SIZE)
1060 hash_function((char *)rand_buf, CHALLENGE_SIZE, challenge_hash);
1061 if (memcmp(challenge_hash, buf, HASH_SIZE))
1063 /* auth successful */
1065 PARA_INFO_LOG("good auth for %s\n", cc->u->name);
1066 /* init stream cipher keys with the second part of the random buffer */
1067 cc->scc.recv = sc_new(rand_buf + CHALLENGE_SIZE, SESSION_KEY_LEN);
1068 cc->scc.send = sc_new(rand_buf + CHALLENGE_SIZE + SESSION_KEY_LEN, SESSION_KEY_LEN);
1069 if (cc->use_sideband)
1070 ret = send_sb(&cc->scc, NULL, 0, SBD_PROCEED, false);
1072 ret = sc_send_buffer(&cc->scc, PROCEED_MSG);
1075 if (cc->use_sideband) {
1077 ret = recv_sb(&cc->scc, SBD_COMMAND, MAX_COMMAND_LEN, &iov);
1080 ret = parse_sb_command(cc, &iov);
1085 ret = read_command(&cc->scc, &command);
1086 if (ret == -E_COMMAND_SYNTAX)
1091 cc->cmd = parse_cmd(command);
1094 /* valid command, check permissions */
1095 ret = check_perms(cc->u->perms, cc->cmd);
1098 /* valid command and sufficient perms */
1099 ret = create_argv(command, "\n", &cc->argv);
1104 PARA_NOTICE_LOG("calling com_%s() for %s@%s\n", cc->cmd->name,
1105 cc->u->name, peername);
1106 ret = cc->cmd->handler(cc);
1107 free_argv(cc->argv);
1108 mutex_lock(mmd_mutex);
1109 mmd->num_commands++;
1110 mutex_unlock(mmd_mutex);
1114 if (send_strerror(cc, -ret) >= 0 && cc->use_sideband)
1115 send_sb(&cc->scc, NULL, 0, SBD_EXIT__FAILURE, true);
1117 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
1121 mutex_lock(mmd_mutex);
1122 if (cc->cmd && (cc->cmd->perms & AFS_WRITE) && ret >= 0)
1124 mmd->active_connections--;
1125 mutex_unlock(mmd_mutex);
1126 if (ret >= 0 && cc->use_sideband) {
1127 ret = send_sb(&cc->scc, NULL, 0, SBD_EXIT__SUCCESS, true);
1129 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
1131 sc_free(cc->scc.recv);
1132 sc_free(cc->scc.send);
1133 exit(ret < 0? EXIT_FAILURE : EXIT_SUCCESS);