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 */
11 #include <sys/types.h>
13 #include <openssl/rc4.h>
17 #include "server.cmdline.h"
18 #include "afs_common.h"
30 #include "user_list.h"
31 #include "server_command_list.h"
32 #include "afs_command_list.h"
34 /** commands including options must be shorter than this */
35 #define MAX_COMMAND_LEN 32768
37 static RC4_KEY rc4_recv_key;
38 static RC4_KEY rc4_send_key;
39 static unsigned char rc4_buf[2 * RC4_KEY_LEN];
41 extern const char *status_item_list[NUM_STAT_ITEMS];
42 extern struct misc_meta_data *mmd;
43 extern struct audio_file_selector selectors[];
44 extern struct sender senders[];
46 static void dummy(__a_unused int s)
49 static void mmd_dup(struct misc_meta_data *new_mmd)
57 * compute human readable string containing
58 * vss status for given integer value
60 static char *vss_status_tohuman(unsigned int flags)
62 if (flags & VSS_PLAYING)
63 return para_strdup("playing");
64 else if (flags & VSS_NEXT)
65 return para_strdup("stopped");
67 return para_strdup("paused");
71 * return human readable permission string. Never returns NULL.
73 static char *cmd_perms_itohuman(unsigned int perms)
75 char *msg = para_malloc(5 * sizeof(char));
77 msg[0] = perms & AFS_READ? 'a' : '-';
78 msg[1] = perms & AFS_WRITE? 'A' : '-';
79 msg[2] = perms & VSS_READ? 'v' : '-';
80 msg[3] = perms & VSS_WRITE? 'V' : '-';
88 static char *vss_get_status_flags(unsigned int flags)
90 char *msg = para_malloc(5 * sizeof(char));
92 msg[0] = (flags & VSS_PLAYING)? 'P' : '_';
93 msg[1] = (flags & VSS_NOMORE)? 'O' : '_';
94 msg[2] = (flags & VSS_NEXT)? 'N' : '_';
95 msg[3] = (flags & VSS_REPOS)? 'R' : '_';
101 * compute status bar string. Never returns NULL
103 static char *get_sb_string(struct misc_meta_data *nmmd)
106 long long unsigned secs = 0, rsecs = 0, percent = 0;
108 base = para_basename(nmmd->filename);
110 return para_strdup("");
113 if (nmmd->afi.chunks_total) {
114 secs = (long long) nmmd->afi.seconds_total * nmmd->chunks_sent
115 / nmmd->afi.chunks_total;
116 rsecs = (long long) nmmd->afi.seconds_total *
117 (nmmd->afi.chunks_total - nmmd->chunks_sent)
118 / nmmd->afi.chunks_total;
119 percent = 100 * ((nmmd->chunks_sent + 5) / 10)
120 / ((nmmd->afi.chunks_total + 5) / 10);
122 ret = make_message("%llu:%02llu [%llu:%02llu] (%llu%%) %s",
123 secs / 60, secs % 60,
124 rsecs / 60, rsecs % 60,
132 static char *get_status(struct misc_meta_data *nmmd)
134 char *bar, *ret, mtime[30] = "";
135 char *status, *flags; /* vss status info */
136 char *ut = uptime_str();
137 long offset = (nmmd->offset + 500) / 1000;
141 if (nmmd->audio_format >= 0) {
142 localtime_r(&nmmd->mtime, &mtime_tm);
143 strftime(mtime, 29, "%a %b %d %Y", &mtime_tm);
145 /* report real status */
146 status = vss_status_tohuman(nmmd->vss_status_flags);
147 flags = vss_get_status_flags(nmmd->vss_status_flags);
148 bar = para_basename(nmmd->filename);
149 gettimeofday(&now, NULL);
151 "%s:%zu\n" "%s:%s\n" "%s:%lu\n" "%s:%u\n"
152 "%s:%s\n" "%s:%s\n" "%s:%s\n" "%s:%s\n"
153 "%s:%li\n" "%s:%s\n" "%s" "%s"
154 "%s:%s\n" "%s:%lu.%lu\n" "%s:%lu.%lu\n",
155 status_item_list[SI_FILE_SIZE], nmmd->size / 1024,
156 status_item_list[SI_MTIME], mtime,
157 status_item_list[SI_LENGTH], nmmd->afi.seconds_total,
158 status_item_list[SI_NUM_PLAYED], nmmd->num_played,
160 status_item_list[SI_STATUS_BAR], bar ? bar : "(none)",
161 status_item_list[SI_STATUS], status,
162 status_item_list[SI_STATUS_FLAGS], flags,
163 status_item_list[SI_SELECTOR], selectors[nmmd->selector_num].name,
165 status_item_list[SI_OFFSET], offset,
166 status_item_list[SI_FORMAT], audio_format_name(nmmd->audio_format),
168 nmmd->afi.info_string,
170 status_item_list[SI_UPTIME], ut,
171 status_item_list[SI_STREAM_START],
172 (long unsigned)nmmd->stream_start.tv_sec,
173 (long unsigned)nmmd->stream_start.tv_usec,
174 status_item_list[SI_CURRENT_TIME],
175 (long unsigned)now.tv_sec,
176 (long unsigned)now.tv_usec
186 static int check_sender_args(int argc, char * const * argv, struct sender_command_data *scd)
189 /* this has to match sender.h */
190 const char *subcmds[] = {"add", "delete", "allow", "deny", "on", "off", NULL};
192 scd->sender_num = -1;
194 return -E_COMMAND_SYNTAX;
195 for (i = 0; senders[i].name; i++)
196 if (!strcmp(senders[i].name, argv[1]))
198 PARA_DEBUG_LOG("%d:%s\n", argc, argv[1]);
199 if (!senders[i].name)
200 return -E_COMMAND_SYNTAX;
202 for (i = 0; subcmds[i]; i++)
203 if (!strcmp(subcmds[i], argv[2]))
206 return -E_COMMAND_SYNTAX;
209 if (!senders[scd->sender_num].client_cmds[scd->cmd_num]) {
211 return -E_SENDER_CMD;
214 switch (scd->cmd_num) {
218 return -E_COMMAND_SYNTAX;
222 if (argc != 4 && argc != 5)
223 return -E_COMMAND_SYNTAX;
224 if (!inet_pton(AF_INET, argv[3], &scd->addr))
225 return -E_COMMAND_SYNTAX;
228 scd->netmask = atoi(argv[4]);
229 if (scd->netmask < 0 || scd->netmask > 32)
230 return -E_COMMAND_SYNTAX;
235 if (argc != 4 && argc != 5)
236 return -E_COMMAND_SYNTAX;
237 if (!inet_pton(AF_INET, argv[3], &scd->addr))
238 return -E_COMMAND_SYNTAX;
241 scd->port = atoi(argv[4]);
242 if (scd->port < 0 || scd->port > 65535)
243 return -E_COMMAND_SYNTAX;
247 return -E_COMMAND_SYNTAX;
252 int com_sender(int fd, int argc, char * const * argv)
255 struct sender_command_data scd;
259 for (i = 0; senders[i].name; i++) {
260 char *tmp = make_message("%s%s\n",
261 msg? msg : "", senders[i].name);
265 ret = send_buffer(fd, msg);
269 ret = check_sender_args(argc, argv, &scd);
272 if (scd.sender_num < 0)
274 msg = senders[scd.sender_num].help();
275 send_buffer(fd, msg);
279 for (i = 0; i < 10; i++) {
281 if (mmd->sender_cmd_data.cmd_num >= 0) {
286 mmd->sender_cmd_data = scd;
290 return (i < 10)? 1 : -E_LOCK;
294 int com_si(int fd, int argc, __a_unused char * const * argv)
298 char *selector_string = NULL, *sender_info = NULL, *sender_list = NULL;
301 return -E_COMMAND_SYNTAX;
303 for (i = 0; selectors[i].name; i++) {
304 selector_string = para_strcat(selector_string, selectors[i].name);
305 selector_string = para_strcat(selector_string, " ");
307 for (i = 0; senders[i].name; i++) {
308 char *info = senders[i].info();
309 sender_info = para_strcat(sender_info, info);
311 sender_list = para_strcat(sender_list, senders[i].name);
312 sender_list = para_strcat(sender_list, " ");
315 ret = send_va_buffer(fd, "up: %s\nplayed: %u\n"
317 "connections (active/accepted/total): %u/%u/%u\n"
318 "current loglevel: %i\n"
319 "supported audio file selectors: %s\n"
320 "supported audio formats: %s\n"
321 "supported senders: %s\n"
325 mmd->active_connections,
330 supported_audio_formats(),
336 free(selector_string);
343 int com_version(int fd, int argc, __a_unused char * const * argv)
346 return -E_COMMAND_SYNTAX;
347 return send_buffer(fd, VERSION_TEXT("server")
348 "built: " BUILD_DATE "\n"
349 SYSTEM ", " CC_VERSION "\n"
354 int com_sc(int fd, int argc, char * const * argv)
357 int ret, old = 0, count = -1; /* print af change forever */
360 count = atoi(argv[1]);
363 if (old != mmd->num_played) {
364 old = mmd->num_played;
365 name = para_strdup(mmd->filename);
369 ret = send_va_buffer(fd, "%s\n", name);
374 if (argc > 1 && !--count)
382 int com_sb(int fd, int argc, char * const * argv)
385 int ret, nr = -1; /* status bar will be printed that many
386 * times. Negative value means: print
393 sb = get_sb_string(mmd);
395 ret = send_va_buffer(fd, "%s\n", sb);
409 int com_stat(int fd, int argc, char * const * argv)
411 int ret, num = 0;/* status will be printed that many
412 * times. num <= 0 means: print forever
414 struct misc_meta_data tmp, *nmmd = &tmp;
417 signal(SIGUSR1, dummy);
424 s = get_status(nmmd);
425 ret = send_buffer(fd, s);
434 return -E_SERVER_CRASH;
440 static int send_list_of_commands(int fd, struct server_command *cmd,
445 for (i = 1; cmd->name; cmd++, i++) {
446 char *perms = cmd_perms_itohuman(cmd->perms);
447 ret = send_va_buffer(fd, "%s\t%s\t%s\t%s\n", cmd->name,
458 /* always returns string that must be freed by the caller in handler */
459 static struct server_command *get_cmd_ptr(const char *name, char **handler)
461 struct server_command *cmd;
463 for (cmd = server_cmds; cmd->name; cmd++)
464 if (!strcmp(cmd->name, name)) {
466 *handler = para_strdup("para_server"); /* server commands */
469 /* not found, look for commands supported by the current selector */
472 *handler = make_message("the %s selector",
473 selectors[mmd->selector_num].name);
474 cmd = selectors[mmd->selector_num].cmd_list;
476 for (; cmd->name; cmd++)
477 if (!strcmp(cmd->name, name))
479 /* not found, look for commands supported by afs */
480 for (cmd = afs_cmds; cmd->name; cmd++)
481 if (!strcmp(cmd->name, name))
487 int com_help(int fd, int argc, char * const * argv)
489 struct server_command *cmd;
490 char *perms, *handler;
494 /* no argument given, print list of commands */
495 if ((ret = send_list_of_commands(fd, server_cmds, "server")) < 0)
498 handler = para_strdup(selectors[mmd->selector_num].name);
499 cmd = selectors[mmd->selector_num].cmd_list;
501 ret = send_list_of_commands(fd, cmd, handler);
506 return send_list_of_commands(fd, cmd, "afs");
508 /* argument given for help */
509 cmd = get_cmd_ptr(argv[1], &handler);
514 perms = cmd_perms_itohuman(cmd->perms);
515 ret = send_va_buffer(fd,
534 int com_hup(__a_unused int fd, int argc, __a_unused char * const * argv)
537 return -E_COMMAND_SYNTAX;
538 kill(getppid(), SIGHUP);
543 int com_term(__a_unused int fd, int argc, __a_unused char * const * argv)
546 return -E_COMMAND_SYNTAX;
547 kill(getppid(), SIGTERM);
551 int com_play(__a_unused int fd, int argc, __a_unused char * const * argv)
554 return -E_COMMAND_SYNTAX;
556 mmd->new_vss_status_flags |= VSS_PLAYING;
557 mmd->new_vss_status_flags &= ~VSS_NOMORE;
564 int com_stop(__a_unused int fd, int argc, __a_unused char * const * argv)
567 return -E_COMMAND_SYNTAX;
569 mmd->new_vss_status_flags &= ~VSS_PLAYING;
570 mmd->new_vss_status_flags &= ~VSS_REPOS;
571 mmd->new_vss_status_flags |= VSS_NEXT;
577 int com_pause(__a_unused int fd, int argc, __a_unused char * const * argv)
580 return -E_COMMAND_SYNTAX;
584 mmd->new_vss_status_flags &= ~VSS_PLAYING;
585 mmd->new_vss_status_flags &= ~VSS_NEXT;
590 int com_chs(int fd, int argc, char * const * argv)
597 selector = para_strdup(selectors[mmd->selector_num].name);
599 ret = send_va_buffer(fd, "%s\n", selector);
603 for (i = 0; selectors[i].name; i++) {
604 if (strcmp(selectors[i].name, argv[1]))
607 mmd->selector_change = i;
612 return -E_BAD_SELECTOR;
616 int com_next(__a_unused int fd, int argc, __a_unused char * const * argv)
619 return -E_COMMAND_SYNTAX;
622 mmd->new_vss_status_flags |= VSS_NEXT;
628 int com_nomore(__a_unused int fd, int argc, __a_unused char * const * argv)
631 return -E_COMMAND_SYNTAX;
633 if (vss_playing() || vss_paused())
634 mmd->new_vss_status_flags |= VSS_NOMORE;
640 int com_ff(__a_unused int fd, int argc, char * const * argv)
643 int ret, backwards = 0;
648 return -E_COMMAND_SYNTAX;
649 if (!(ret = sscanf(argv[1], "%u%c", &i, &c)))
650 return -E_COMMAND_SYNTAX;
651 if (ret > 1 && c == '-')
652 backwards = 1; /* jmp backwards */
654 ret = -E_NO_AUDIO_FILE;
655 if (!mmd->afi.chunks_total || !mmd->afi.seconds_total)
657 promille = (1000 * mmd->current_chunk) / mmd->afi.chunks_total;
659 promille -= 1000 * i / mmd->afi.seconds_total;
661 promille += 1000 * i / mmd->afi.seconds_total;
664 if (promille > 1000) {
665 mmd->new_vss_status_flags |= VSS_NEXT;
668 mmd->repos_request = (mmd->afi.chunks_total * promille) / 1000;
669 mmd->new_vss_status_flags |= VSS_REPOS;
670 mmd->new_vss_status_flags &= ~VSS_NEXT;
679 int com_jmp(__a_unused int fd, int argc, char * const * argv)
685 return -E_COMMAND_SYNTAX;
686 if (sscanf(argv[1], "%lu", &i) <= 0)
687 return -E_COMMAND_SYNTAX;
689 ret = -E_NO_AUDIO_FILE;
690 if (!mmd->afi.chunks_total)
694 PARA_INFO_LOG("jumping to %lu%%\n", i);
695 mmd->repos_request = (mmd->afi.chunks_total * i + 50)/ 100;
696 PARA_INFO_LOG("sent: %lu, offset before jmp: %lu\n",
697 mmd->chunks_sent, mmd->offset);
698 mmd->new_vss_status_flags |= VSS_REPOS;
699 mmd->new_vss_status_flags &= ~VSS_NEXT;
708 * check if perms are sufficient to exec a command having perms cmd_perms.
709 * Returns 0 if perms are sufficient, -E_PERM otherwise.
711 static int check_perms(unsigned int perms, struct server_command *cmd_ptr)
713 PARA_DEBUG_LOG("%s", "checking permissions\n");
714 return (cmd_ptr->perms & perms) < cmd_ptr->perms ? -E_PERM : 0;
718 * Parse first string from *cmd and lookup in table of valid commands.
719 * On error, NULL is returned.
721 static struct server_command *parse_cmd(const char *cmdstr)
726 sscanf(cmdstr, "%200s%n", buf, &n);
730 return get_cmd_ptr(buf, NULL);
733 static long int para_rand(long unsigned max)
735 return (long int) ((max + 0.0) * (random() / (RAND_MAX + 1.0)));
738 static void init_rc4_keys(void)
742 for (i = 0; i < 2 * RC4_KEY_LEN; i++)
743 rc4_buf[i] = para_rand(256);
744 PARA_DEBUG_LOG("rc4 keys initialized (%u:%u)\n",
745 (unsigned char) rc4_buf[0],
746 (unsigned char) rc4_buf[RC4_KEY_LEN]);
747 RC4_set_key(&rc4_recv_key, RC4_KEY_LEN, rc4_buf);
748 RC4_set_key(&rc4_send_key, RC4_KEY_LEN, rc4_buf + RC4_KEY_LEN);
751 static void rc4_recv(unsigned long len, const unsigned char *indata,
752 unsigned char *outdata, __a_unused void *private_data)
754 RC4(&rc4_recv_key, len, indata, outdata);
757 static void rc4_send(unsigned long len, const unsigned char *indata,
758 unsigned char *outdata, __a_unused void *private_data)
760 RC4(&rc4_send_key, len, indata, outdata);
763 static int read_command(int fd, char **result)
767 char *command = NULL;
773 ret = recv_buffer(fd, buf, sizeof(buf));
779 ret = -E_COMMAND_SYNTAX;
780 if (command && numbytes + strlen(command) > MAX_COMMAND_LEN) /* DOS */
782 command = para_strcat(command, buf);
783 p = strstr(command, EOC_MSG);
789 ret = command? 1 : -E_COMMAND_SYNTAX;
800 * perform user authentication and execute a command
802 * \param fd the file descriptor to send output to
803 * \param addr socket address info of peer
805 * \return EXIT_SUCCESS or EXIT_FAILURE
807 * Whenever para_server accepts an incoming tcp connection on
808 * the port it listens on, it forks and the resulting child
809 * calls this function.
811 * An RSA-based challenge/response is used to authenticate
812 * the peer. It that authentication succeeds, a random RC4
813 * session key is generated and sent back to the peer,
814 * encrypted with its RSA public key. From this point on,
815 * all transfers are crypted with this session key.
817 * Next it is checked if the peer supplied a valid server
818 * command or a command for the audio file selector currently
819 * in use. If yes, and if the user has sufficient
820 * permissions to execute that command, the function calls
821 * the corresponding command handler which does argument
822 * checking and further processing.
824 * In order to cope with a DOS attacks, a timeout is set up
825 * which terminates the function if the connection was not
826 * authenticated when the timeout expires.
828 * \sa alarm(2), rc4(3), crypt.c, crypt.h
830 int handle_connect(int fd, struct sockaddr_in *addr)
832 int ret, argc, use_rc4 = 0;
834 unsigned char crypt_buf[MAXLINE];
836 struct server_command *cmd = NULL;
837 long unsigned challenge_nr, chall_response;
839 char *p, *command = NULL;
842 signal(SIGCHLD, SIG_IGN);
843 signal(SIGINT, SIG_DFL);
844 signal(SIGTERM, SIG_DFL);
845 signal(SIGHUP, SIG_DFL);
846 signal(SIGUSR1, SIG_IGN);
848 challenge_nr = random();
849 /* send Welcome message */
850 ret = send_va_buffer(fd, "This is para_server, version "
851 PACKAGE_VERSION ".\n" );
854 /* recv auth request line */
855 ret = recv_buffer(fd, buf, sizeof(buf));
864 if (strncmp(buf, "auth ", 5))
867 if (numbytes < 9 || strncmp(buf, "auth rc4 ", 9))
868 p = buf + 5; /* client version < 0.2.6 */
870 p = buf + 9; /* client version >= 0.2.6 */
873 PARA_DEBUG_LOG("received %s request for user %s\n",
874 use_rc4? "rc4" : "auth", p);
879 ret = para_encrypt_challenge(u->rsa, challenge_nr, crypt_buf);
883 PARA_DEBUG_LOG("sending %zu byte challenge\n", numbytes);
884 /* We can't use send_buffer here since buf may contain null bytes */
885 ret = send_bin_buffer(fd,(char *) crypt_buf, numbytes);
888 /* recv decrypted number */
889 ret = recv_buffer(fd, buf, sizeof(buf));
896 if (sscanf(buf, CHALLENGE_RESPONSE_MSG "%lu", &chall_response) < 1
897 || chall_response != challenge_nr)
899 /* auth successful, send 'Proceed' message */
900 PARA_INFO_LOG("good auth for %s (%lu)\n", u->name, challenge_nr);
901 sprintf(buf, "%s", PROCEED_MSG);
904 ret = para_encrypt_buffer(u->rsa, rc4_buf, 2 * RC4_KEY_LEN,
905 (unsigned char *)buf + PROCEED_MSG_LEN + 1);
908 numbytes = ret + strlen(PROCEED_MSG) + 1;
910 numbytes = strlen(buf);
911 ret = send_bin_buffer(fd, buf, numbytes);
915 enable_crypt(fd, rc4_recv, rc4_send, NULL);
916 ret = read_command(fd, &command);
920 cmd = parse_cmd(command);
923 /* valid command, check permissions */
924 ret = check_perms(u->perms, cmd);
927 /* valid command and sufficient perms */
929 argc = split_args(command, &argv, "\n");
933 PARA_NOTICE_LOG("calling com_%s() for %s@%s\n", cmd->name, u->name,
934 inet_ntoa(addr->sin_addr));
935 ret = cmd->handler(fd, argc, argv);
941 PARA_NOTICE_LOG("%s\n", PARA_STRERROR(-ret));
942 if (ret != -E_SEND && ret != -E_RECV)
943 send_va_buffer(fd, "%s\n", PARA_STRERROR(-ret));
949 if (cmd && (cmd->perms & AFS_WRITE) && ret >= 0)
951 mmd->active_connections--;