2 * Copyright (C) 1997-2007 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file command.c does client authentication and executes server commands */
9 #include <sys/time.h> /* gettimeofday */
10 #include "para.h" /* gettimeofday */
12 #include "server.cmdline.h"
13 #include "afs_common.h"
19 #include <openssl/rc4.h>
25 #include "user_list.h"
26 #include "server_command_list.h"
28 /** commands including options must be shorter than this */
29 #define MAX_COMMAND_LEN 4096
31 static RC4_KEY rc4_recv_key;
32 static RC4_KEY rc4_send_key;
33 static unsigned char rc4_buf[2 * RC4_KEY_LEN];
35 extern const char *status_item_list[NUM_STAT_ITEMS];
36 extern struct misc_meta_data *mmd;
37 extern struct audio_file_selector selectors[];
38 extern struct sender senders[];
40 static void dummy(__a_unused int s)
43 static void mmd_dup(struct misc_meta_data *new_mmd)
51 * compute human readable string containing
52 * vss status for given integer value
54 static char *vss_status_tohuman(unsigned int flags)
56 if (flags & VSS_PLAYING)
57 return para_strdup("playing");
58 else if (flags & VSS_NEXT)
59 return para_strdup("stopped");
61 return para_strdup("paused");
65 * return human readable permission string. Never returns NULL.
67 static char *cmd_perms_itohuman(unsigned int perms)
69 char *msg = para_malloc(5 * sizeof(char));
71 msg[0] = perms & AFS_READ? 'a' : '-';
72 msg[1] = perms & AFS_WRITE? 'A' : '-';
73 msg[2] = perms & VSS_READ? 'v' : '-';
74 msg[3] = perms & VSS_WRITE? 'V' : '-';
82 static char *vss_get_status_flags(unsigned int flags)
84 char *msg = para_malloc(5 * sizeof(char));
86 msg[0] = (flags & VSS_PLAYING)? 'P' : '_';
87 msg[1] = (flags & VSS_NOMORE)? 'O' : '_';
88 msg[2] = (flags & VSS_NEXT)? 'N' : '_';
89 msg[3] = (flags & VSS_REPOS)? 'R' : '_';
95 * compute status bar string. Never returns NULL
97 static char *get_sb_string(struct misc_meta_data *nmmd)
100 long long unsigned secs = 0, rsecs = 0, percent = 0;
102 base = para_basename(nmmd->filename);
104 return para_strdup("");
107 if (nmmd->afi.chunks_total) {
108 secs = (long long) nmmd->afi.seconds_total * nmmd->chunks_sent
109 / nmmd->afi.chunks_total;
110 rsecs = (long long) nmmd->afi.seconds_total *
111 (nmmd->afi.chunks_total - nmmd->chunks_sent)
112 / nmmd->afi.chunks_total;
113 percent = 100 * ((nmmd->chunks_sent + 5) / 10)
114 / ((nmmd->afi.chunks_total + 5) / 10);
116 ret = make_message("%llu:%02llu [%llu:%02llu] (%llu%%) %s",
117 secs / 60, secs % 60,
118 rsecs / 60, rsecs % 60,
126 static char *get_status(struct misc_meta_data *nmmd)
128 char *bar, *ret, mtime[30] = "";
129 char *status, *flags; /* vss status info */
130 char *ut = uptime_str();
131 long offset = (nmmd->offset + 500) / 1000;
135 if (nmmd->audio_format >= 0) {
136 localtime_r(&nmmd->mtime, &mtime_tm);
137 strftime(mtime, 29, "%a %b %d %Y", &mtime_tm);
139 /* report real status */
140 status = vss_status_tohuman(nmmd->vss_status_flags);
141 flags = vss_get_status_flags(nmmd->vss_status_flags);
142 bar = para_basename(nmmd->filename);
143 gettimeofday(&now, NULL);
145 "%s:%zu\n" "%s:%s\n" "%s:%lu\n" "%s:%u\n"
146 "%s:%s\n" "%s:%s\n" "%s:%s\n" "%s:%s\n"
147 "%s:%li\n" "%s:%s\n" "%s" "%s"
148 "%s:%s\n" "%s:%lu.%lu\n" "%s:%lu.%lu\n",
149 status_item_list[SI_FILE_SIZE], nmmd->size / 1024,
150 status_item_list[SI_MTIME], mtime,
151 status_item_list[SI_LENGTH], nmmd->afi.seconds_total,
152 status_item_list[SI_NUM_PLAYED], nmmd->num_played,
154 status_item_list[SI_STATUS_BAR], bar ? bar : "(none)",
155 status_item_list[SI_STATUS], status,
156 status_item_list[SI_STATUS_FLAGS], flags,
157 status_item_list[SI_SELECTOR], selectors[nmmd->selector_num].name,
159 status_item_list[SI_OFFSET], offset,
160 status_item_list[SI_FORMAT], audio_format_name(nmmd->audio_format),
162 nmmd->afi.info_string,
164 status_item_list[SI_UPTIME], ut,
165 status_item_list[SI_STREAM_START],
166 (long unsigned)nmmd->stream_start.tv_sec,
167 (long unsigned)nmmd->stream_start.tv_usec,
168 status_item_list[SI_CURRENT_TIME],
169 (long unsigned)now.tv_sec,
170 (long unsigned)now.tv_usec
180 static int check_sender_args(int argc, char **argv, struct sender_command_data *scd)
183 /* this has to match sender.h */
184 const char *subcmds[] = {"add", "delete", "allow", "deny", "on", "off", NULL};
186 scd->sender_num = -1;
188 return -E_COMMAND_SYNTAX;
189 for (i = 0; senders[i].name; i++)
190 if (!strcmp(senders[i].name, argv[1]))
192 PARA_DEBUG_LOG("%d:%s\n", argc, argv[1]);
193 if (!senders[i].name)
194 return -E_COMMAND_SYNTAX;
196 for (i = 0; subcmds[i]; i++)
197 if (!strcmp(subcmds[i], argv[2]))
200 return -E_COMMAND_SYNTAX;
203 if (!senders[scd->sender_num].client_cmds[scd->cmd_num]) {
205 return -E_SENDER_CMD;
208 switch (scd->cmd_num) {
212 return -E_COMMAND_SYNTAX;
216 if (argc != 4 && argc != 5)
217 return -E_COMMAND_SYNTAX;
218 if (!inet_aton(argv[3], &scd->addr))
219 return -E_COMMAND_SYNTAX;
222 scd->netmask = atoi(argv[4]);
223 if (scd->netmask < 0 || scd->netmask > 32)
224 return -E_COMMAND_SYNTAX;
229 if (argc != 4 && argc != 5)
230 return -E_COMMAND_SYNTAX;
231 if (!inet_aton(argv[3], &scd->addr))
232 return -E_COMMAND_SYNTAX;
235 scd->port = atoi(argv[4]);
236 if (scd->port < 0 || scd->port > 65535)
237 return -E_COMMAND_SYNTAX;
241 return -E_COMMAND_SYNTAX;
246 int com_sender(int fd, int argc, char **argv)
249 struct sender_command_data scd;
253 for (i = 0; senders[i].name; i++) {
254 char *tmp = make_message("%s%s\n",
255 msg? msg : "", senders[i].name);
259 ret = send_buffer(fd, msg);
263 ret = check_sender_args(argc, argv, &scd);
266 if (scd.sender_num < 0)
268 msg = senders[scd.sender_num].help();
269 send_buffer(fd, msg);
273 for (i = 0; i < 10; i++) {
275 if (mmd->sender_cmd_data.cmd_num >= 0) {
280 mmd->sender_cmd_data = scd;
284 return (i < 10)? 1 : -E_LOCK;
288 int com_si(int fd, int argc, __a_unused char **argv)
292 char *selector_string = NULL, *sender_info = NULL, *sender_list = NULL;
295 return -E_COMMAND_SYNTAX;
297 for (i = 0; selectors[i].name; i++) {
298 selector_string = para_strcat(selector_string, selectors[i].name);
299 selector_string = para_strcat(selector_string, " ");
301 for (i = 0; senders[i].name; i++) {
302 char *info = senders[i].info();
303 sender_info = para_strcat(sender_info, info);
305 sender_list = para_strcat(sender_list, senders[i].name);
306 sender_list = para_strcat(sender_list, " ");
309 ret = send_va_buffer(fd, "up: %s\nplayed: %u\n"
311 "connections (active/accepted/total): %u/%u/%u\n"
312 "current loglevel: %i\n"
313 "supported audio file selectors: %s\n"
314 "supported audio formats: %s\n"
315 "supported senders: %s\n"
319 mmd->active_connections,
324 supported_audio_formats(),
330 free(selector_string);
337 int com_version(int fd, int argc, __a_unused char **argv)
340 return -E_COMMAND_SYNTAX;
341 return send_buffer(fd, VERSION_TEXT("server")
342 "built: " BUILD_DATE "\n"
343 SYSTEM ", " CC_VERSION "\n"
348 int com_sc(int fd, int argc, char **argv)
351 int ret, old = 0, count = -1; /* print af change forever */
354 count = atoi(argv[1]);
357 if (old != mmd->num_played) {
358 old = mmd->num_played;
359 name = para_strdup(mmd->filename);
363 ret = send_va_buffer(fd, "%s\n", name);
368 if (argc > 1 && !--count)
376 int com_sb(int fd, int argc, char **argv)
379 int ret, nr = -1; /* status bar will be printed that many
380 * times. Negative value means: print
387 sb = get_sb_string(mmd);
389 ret = send_va_buffer(fd, "%s\n", sb);
403 int com_stat(int fd, int argc, char **argv)
405 int ret, num = 0;/* status will be printed that many
406 * times. num <= 0 means: print forever
408 struct misc_meta_data tmp, *nmmd = &tmp;
411 signal(SIGUSR1, dummy);
418 s = get_status(nmmd);
419 ret = send_buffer(fd, s);
428 return -E_SERVER_CRASH;
434 static int send_list_of_commands(int fd, struct server_command *cmd,
439 for (i = 1; cmd->name; cmd++, i++) {
440 char *perms = cmd_perms_itohuman(cmd->perms);
441 ret = send_va_buffer(fd, "%s\t%s\t%s\t%s\n", cmd->name,
452 /* always returns string that must be freed by the caller in handler */
453 static struct server_command *get_cmd_ptr(char *name, char **handler)
455 struct server_command *cmd;
457 for (cmd = server_cmds; cmd->name; cmd++)
458 if (!strcmp(cmd->name, name)) {
460 *handler = para_strdup("para_server"); /* server commands */
463 /* not found, look for commands supported by the current selector */
466 *handler = make_message("the %s selector",
467 selectors[mmd->selector_num].name);
468 cmd = selectors[mmd->selector_num].cmd_list;
470 for (; cmd->name; cmd++)
471 if (!strcmp(cmd->name, name))
477 int com_help(int fd, int argc, char **argv)
479 struct server_command *cmd;
480 char *perms, *handler;
484 /* no argument given, print list of commands */
485 if ((ret = send_list_of_commands(fd, server_cmds, "server")) < 0)
488 handler = para_strdup(selectors[mmd->selector_num].name);
489 cmd = selectors[mmd->selector_num].cmd_list;
491 ret = send_list_of_commands(fd, cmd, handler);
495 /* argument given for help */
496 cmd = get_cmd_ptr(argv[1], &handler);
501 perms = cmd_perms_itohuman(cmd->perms);
502 ret = send_va_buffer(fd,
521 int com_hup(__a_unused int fd, int argc, __a_unused char **argv)
524 return -E_COMMAND_SYNTAX;
525 kill(getppid(), SIGHUP);
530 int com_term(__a_unused int fd, int argc, __a_unused char **argv)
533 return -E_COMMAND_SYNTAX;
534 kill(getppid(), SIGTERM);
538 int com_play(__a_unused int fd, int argc, __a_unused char **argv)
541 return -E_COMMAND_SYNTAX;
543 mmd->new_vss_status_flags |= VSS_PLAYING;
544 mmd->new_vss_status_flags &= ~VSS_NOMORE;
551 int com_stop(__a_unused int fd, int argc, __a_unused char **argv)
554 return -E_COMMAND_SYNTAX;
556 mmd->new_vss_status_flags &= ~VSS_PLAYING;
557 mmd->new_vss_status_flags &= ~VSS_REPOS;
558 mmd->new_vss_status_flags |= VSS_NEXT;
564 int com_pause(__a_unused int fd, int argc, __a_unused char **argv)
567 return -E_COMMAND_SYNTAX;
571 mmd->new_vss_status_flags &= ~VSS_PLAYING;
572 mmd->new_vss_status_flags &= ~VSS_NEXT;
577 int com_chs(int fd, int argc, char **argv)
584 selector = para_strdup(selectors[mmd->selector_num].name);
586 ret = send_va_buffer(fd, "%s\n", selector);
590 for (i = 0; selectors[i].name; i++) {
591 if (strcmp(selectors[i].name, argv[1]))
594 mmd->selector_change = i;
599 return -E_BAD_SELECTOR;
603 int com_next(__a_unused int fd, int argc, __a_unused char **argv)
606 return -E_COMMAND_SYNTAX;
609 mmd->new_vss_status_flags |= VSS_NEXT;
615 int com_nomore(__a_unused int fd, int argc, __a_unused char **argv)
618 return -E_COMMAND_SYNTAX;
620 if (vss_playing() || vss_paused())
621 mmd->new_vss_status_flags |= VSS_NOMORE;
627 int com_ff(__a_unused int fd, int argc, char **argv)
630 int ret, backwards = 0;
635 return -E_COMMAND_SYNTAX;
636 if (!(ret = sscanf(argv[1], "%u%c", &i, &c)))
637 return -E_COMMAND_SYNTAX;
638 if (ret > 1 && c == '-')
639 backwards = 1; /* jmp backwards */
641 ret = -E_NO_AUDIO_FILE;
642 if (!mmd->afi.chunks_total || !mmd->afi.seconds_total)
644 promille = (1000 * mmd->current_chunk) / mmd->afi.chunks_total;
646 promille -= 1000 * i / mmd->afi.seconds_total;
648 promille += 1000 * i / mmd->afi.seconds_total;
651 if (promille > 1000) {
652 mmd->new_vss_status_flags |= VSS_NEXT;
655 mmd->repos_request = (mmd->afi.chunks_total * promille) / 1000;
656 mmd->new_vss_status_flags |= VSS_REPOS;
657 mmd->new_vss_status_flags &= ~VSS_NEXT;
666 int com_jmp(__a_unused int fd, int argc, char **argv)
672 return -E_COMMAND_SYNTAX;
673 if (sscanf(argv[1], "%lu", &i) <= 0)
674 return -E_COMMAND_SYNTAX;
676 ret = -E_NO_AUDIO_FILE;
677 if (!mmd->afi.chunks_total)
681 PARA_INFO_LOG("jumping to %lu%%\n", i);
682 mmd->repos_request = (mmd->afi.chunks_total * i + 50)/ 100;
683 PARA_INFO_LOG("sent: %lu, offset before jmp: %lu\n",
684 mmd->chunks_sent, mmd->offset);
685 mmd->new_vss_status_flags |= VSS_REPOS;
686 mmd->new_vss_status_flags &= ~VSS_NEXT;
695 * check if perms are sufficient to exec a command having perms cmd_perms.
696 * Returns 0 if perms are sufficient, -E_PERM otherwise.
698 static int check_perms(unsigned int perms, struct server_command *cmd_ptr)
700 PARA_DEBUG_LOG("%s", "checking permissions\n");
701 return (cmd_ptr->perms & perms) < cmd_ptr->perms ? -E_PERM : 0;
705 * Parse first string from *cmd and lookup in table of valid commands.
706 * On error, NULL is returned.
708 static struct server_command *parse_cmd(const char *cmdstr)
713 sscanf(cmdstr, "%200s%n", buf, &n);
717 return get_cmd_ptr(buf, NULL);
720 static long int para_rand(long unsigned max)
722 return (long int) ((max + 0.0) * (random() / (RAND_MAX + 1.0)));
725 static void init_rc4_keys(void)
729 for (i = 0; i < 2 * RC4_KEY_LEN; i++)
730 rc4_buf[i] = para_rand(256);
731 PARA_DEBUG_LOG("rc4 keys initialized (%u:%u)\n",
732 (unsigned char) rc4_buf[0],
733 (unsigned char) rc4_buf[RC4_KEY_LEN]);
734 RC4_set_key(&rc4_recv_key, RC4_KEY_LEN, rc4_buf);
735 RC4_set_key(&rc4_send_key, RC4_KEY_LEN, rc4_buf + RC4_KEY_LEN);
738 static void rc4_recv(unsigned long len, const unsigned char *indata,
739 unsigned char *outdata, __a_unused void *private_data)
741 RC4(&rc4_recv_key, len, indata, outdata);
744 static void rc4_send(unsigned long len, const unsigned char *indata,
745 unsigned char *outdata, __a_unused void *private_data)
747 RC4(&rc4_send_key, len, indata, outdata);
750 static int read_command(int fd, char **result)
754 char *command = NULL;
760 ret = recv_buffer(fd, buf, sizeof(buf));
766 ret = -E_COMMAND_SYNTAX;
767 if (command && numbytes + strlen(command) > MAX_COMMAND_LEN) /* DOS */
769 command = para_strcat(command, buf);
770 p = strstr(command, EOC_MSG);
776 ret = command? 1 : -E_COMMAND_SYNTAX;
787 * perform user authentication and execute a command
789 * \param fd the file descriptor to send output to
790 * \param addr socket address info of peer
792 * \return EXIT_SUCCESS or EXIT_FAILURE
794 * Whenever para_server accepts an incoming tcp connection on
795 * the port it listens on, it forks and the resulting child
796 * calls this function.
798 * An RSA-based challenge/response is used to authenticate
799 * the peer. It that authentication succeeds, a random RC4
800 * session key is generated and sent back to the peer,
801 * encrypted with its RSA public key. From this point on,
802 * all transfers are crypted with this session key.
804 * Next it is checked if the peer supplied a valid server
805 * command or a command for the audio file selector currently
806 * in use. If yes, and if the user has sufficient
807 * permissions to execute that command, the function calls
808 * the corresponding command handler which does argument
809 * checking and further processing.
811 * In order to cope with a DOS attacks, a timeout is set up
812 * which terminates the function if the connection was not
813 * authenticated when the timeout expires.
815 * \sa alarm(2), rc4(3), crypt.c, crypt.h
817 int handle_connect(int fd, struct sockaddr_in *addr)
819 int ret, argc, use_rc4 = 0;
821 unsigned char crypt_buf[MAXLINE];
823 struct server_command *cmd = NULL;
824 long unsigned challenge_nr, chall_response;
826 char *p, *command = NULL;
829 signal(SIGCHLD, SIG_IGN);
830 signal(SIGINT, SIG_DFL);
831 signal(SIGTERM, SIG_DFL);
832 signal(SIGHUP, SIG_DFL);
833 signal(SIGUSR1, SIG_IGN);
835 challenge_nr = random();
836 /* send Welcome message */
837 ret = send_va_buffer(fd, "This is para_server, version "
838 PACKAGE_VERSION ".\n" );
841 /* recv auth request line */
842 ret = recv_buffer(fd, buf, sizeof(buf));
851 if (strncmp(buf, "auth ", 5))
854 if (numbytes < 9 || strncmp(buf, "auth rc4 ", 9))
855 p = buf + 5; /* client version < 0.2.6 */
857 p = buf + 9; /* client version >= 0.2.6 */
860 PARA_DEBUG_LOG("received %s request for user %s\n",
861 use_rc4? "rc4" : "auth", p);
866 ret = para_encrypt_challenge(u->rsa, challenge_nr, crypt_buf);
870 PARA_DEBUG_LOG("sending %zu byte challenge\n", numbytes);
871 /* We can't use send_buffer here since buf may contain null bytes */
872 ret = send_bin_buffer(fd,(char *) crypt_buf, numbytes);
875 /* recv decrypted number */
876 ret = recv_buffer(fd, buf, sizeof(buf));
883 if (sscanf(buf, CHALLENGE_RESPONSE_MSG "%lu", &chall_response) < 1
884 || chall_response != challenge_nr)
886 /* auth successful, send 'Proceed' message */
887 PARA_INFO_LOG("good auth for %s (%lu)\n", u->name, challenge_nr);
888 sprintf(buf, "%s", PROCEED_MSG);
891 ret = para_encrypt_buffer(u->rsa, rc4_buf, 2 * RC4_KEY_LEN,
892 (unsigned char *)buf + PROCEED_MSG_LEN + 1);
895 numbytes = ret + strlen(PROCEED_MSG) + 1;
897 numbytes = strlen(buf);
898 ret = send_bin_buffer(fd, buf, numbytes);
902 enable_crypt(fd, rc4_recv, rc4_send, NULL);
903 ret = read_command(fd, &command);
907 cmd = parse_cmd(command);
910 /* valid command, check permissions */
911 ret = check_perms(u->perms, cmd);
914 /* valid command and sufficient perms */
916 argc = split_args(command, &argv, "\n");
920 PARA_NOTICE_LOG("calling com_%s() for %s@%s\n", cmd->name, u->name,
921 inet_ntoa(addr->sin_addr));
922 ret = cmd->handler(fd, argc, argv);
928 PARA_NOTICE_LOG("%s\n", PARA_STRERROR(-ret));
929 if (ret != -E_SEND && ret != -E_RECV)
930 send_va_buffer(fd, "%s\n", PARA_STRERROR(-ret));
936 if (cmd && (cmd->perms & AFS_WRITE) && ret >= 0)
938 mmd->active_connections--;