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 "server.cmdline.h"
11 #include "afs_common.h"
16 #include <openssl/rc4.h>
22 #include "user_list.h"
23 #include "server_command_list.h"
25 /** commands including options must be shorter than this */
26 #define MAX_COMMAND_LEN 4096
28 static RC4_KEY rc4_recv_key;
29 static RC4_KEY rc4_send_key;
30 static unsigned char rc4_buf[2 * RC4_KEY_LEN];
32 extern const char *status_item_list[NUM_STAT_ITEMS];
33 extern struct misc_meta_data *mmd;
34 extern struct audio_file_selector selectors[];
35 extern struct sender senders[];
37 static void dummy(__a_unused int s)
40 static void mmd_dup(struct misc_meta_data *new_mmd)
48 * compute human readable string containing
49 * vss status for given integer value
51 static char *vss_status_tohuman(unsigned int flags)
53 if (flags & VSS_PLAYING)
54 return para_strdup("playing");
55 else if (flags & VSS_NEXT)
56 return para_strdup("stopped");
58 return para_strdup("paused");
62 * return human readable permission string. Never returns NULL.
64 static char *cmd_perms_itohuman(unsigned int perms)
66 char *msg = para_malloc(5 * sizeof(char));
68 msg[0] = perms & AFS_READ? 'a' : '-';
69 msg[1] = perms & AFS_WRITE? 'A' : '-';
70 msg[2] = perms & VSS_READ? 'v' : '-';
71 msg[3] = perms & VSS_WRITE? 'V' : '-';
79 static char *vss_get_status_flags(unsigned int flags)
81 char *msg = para_malloc(5 * sizeof(char));
83 msg[0] = (flags & VSS_PLAYING)? 'P' : '_';
84 msg[1] = (flags & VSS_NOMORE)? 'O' : '_';
85 msg[2] = (flags & VSS_NEXT)? 'N' : '_';
86 msg[3] = (flags & VSS_REPOS)? 'R' : '_';
92 * compute status bar string. Never returns NULL
94 static char *get_sb_string(struct misc_meta_data *nmmd)
97 long long unsigned secs = 0, rsecs = 0, percent = 0;
99 base = para_basename(nmmd->filename);
101 return para_strdup("");
104 if (nmmd->afi.chunks_total) {
105 secs = (long long) nmmd->afi.seconds_total * nmmd->chunks_sent
106 / nmmd->afi.chunks_total;
107 rsecs = (long long) nmmd->afi.seconds_total *
108 (nmmd->afi.chunks_total - nmmd->chunks_sent)
109 / nmmd->afi.chunks_total;
110 percent = 100 * ((nmmd->chunks_sent + 5) / 10)
111 / ((nmmd->afi.chunks_total + 5) / 10);
113 ret = make_message("%llu:%02llu [%llu:%02llu] (%llu%%) %s",
114 secs / 60, secs % 60,
115 rsecs / 60, rsecs % 60,
123 static char *get_status(struct misc_meta_data *nmmd)
125 char *bar, *ret, mtime[30] = "";
126 char *status, *flags; /* vss status info */
127 char *ut = uptime_str();
128 long offset = (nmmd->offset + 500) / 1000;
132 if (nmmd->audio_format >= 0) {
133 localtime_r(&nmmd->mtime, &mtime_tm);
134 strftime(mtime, 29, "%a %b %d %Y", &mtime_tm);
136 /* report real status */
137 status = vss_status_tohuman(nmmd->vss_status_flags);
138 flags = vss_get_status_flags(nmmd->vss_status_flags);
139 bar = para_basename(nmmd->filename);
140 gettimeofday(&now, NULL);
142 "%s:%zu\n" "%s:%s\n" "%s:%lu\n" "%s:%u\n"
143 "%s:%s\n" "%s:%s\n" "%s:%s\n" "%s:%s\n"
144 "%s:%li\n" "%s:%s\n" "%s" "%s"
145 "%s:%s\n" "%s:%lu.%lu\n" "%s:%lu.%lu\n",
146 status_item_list[SI_FILE_SIZE], nmmd->size / 1024,
147 status_item_list[SI_MTIME], mtime,
148 status_item_list[SI_LENGTH], nmmd->afi.seconds_total,
149 status_item_list[SI_NUM_PLAYED], nmmd->num_played,
151 status_item_list[SI_STATUS_BAR], bar ? bar : "(none)",
152 status_item_list[SI_STATUS], status,
153 status_item_list[SI_STATUS_FLAGS], flags,
154 status_item_list[SI_SELECTOR], selectors[nmmd->selector_num].name,
156 status_item_list[SI_OFFSET], offset,
157 status_item_list[SI_FORMAT], audio_format_name(nmmd->audio_format),
159 nmmd->afi.info_string,
161 status_item_list[SI_UPTIME], ut,
162 status_item_list[SI_STREAM_START],
163 (long unsigned)nmmd->stream_start.tv_sec,
164 (long unsigned)nmmd->stream_start.tv_usec,
165 status_item_list[SI_CURRENT_TIME],
166 (long unsigned)now.tv_sec,
167 (long unsigned)now.tv_usec
177 static int check_sender_args(int argc, char **argv, struct sender_command_data *scd)
180 /* this has to match sender.h */
181 const char *subcmds[] = {"add", "delete", "allow", "deny", "on", "off", NULL};
183 scd->sender_num = -1;
185 return -E_COMMAND_SYNTAX;
186 for (i = 0; senders[i].name; i++)
187 if (!strcmp(senders[i].name, argv[1]))
189 PARA_DEBUG_LOG("%d:%s\n", argc, argv[1]);
190 if (!senders[i].name)
191 return -E_COMMAND_SYNTAX;
193 for (i = 0; subcmds[i]; i++)
194 if (!strcmp(subcmds[i], argv[2]))
197 return -E_COMMAND_SYNTAX;
200 if (!senders[scd->sender_num].client_cmds[scd->cmd_num]) {
202 return -E_SENDER_CMD;
205 switch (scd->cmd_num) {
209 return -E_COMMAND_SYNTAX;
213 if (argc != 4 && argc != 5)
214 return -E_COMMAND_SYNTAX;
215 if (!inet_aton(argv[3], &scd->addr))
216 return -E_COMMAND_SYNTAX;
219 scd->netmask = atoi(argv[4]);
220 if (scd->netmask < 0 || scd->netmask > 32)
221 return -E_COMMAND_SYNTAX;
226 if (argc != 4 && argc != 5)
227 return -E_COMMAND_SYNTAX;
228 if (!inet_aton(argv[3], &scd->addr))
229 return -E_COMMAND_SYNTAX;
232 scd->port = atoi(argv[4]);
233 if (scd->port < 0 || scd->port > 65535)
234 return -E_COMMAND_SYNTAX;
238 return -E_COMMAND_SYNTAX;
243 int com_sender(int fd, int argc, char **argv)
246 struct sender_command_data scd;
250 for (i = 0; senders[i].name; i++) {
251 char *tmp = make_message("%s%s\n",
252 msg? msg : "", senders[i].name);
256 ret = send_buffer(fd, msg);
260 ret = check_sender_args(argc, argv, &scd);
263 if (scd.sender_num < 0)
265 msg = senders[scd.sender_num].help();
266 send_buffer(fd, msg);
270 for (i = 0; i < 10; i++) {
272 if (mmd->sender_cmd_data.cmd_num >= 0) {
277 mmd->sender_cmd_data = scd;
281 return (i < 10)? 1 : -E_LOCK;
285 int com_si(int fd, int argc, __a_unused char **argv)
289 char *selector_string = NULL, *sender_info = NULL, *sender_list = NULL;
292 return -E_COMMAND_SYNTAX;
294 for (i = 0; selectors[i].name; i++) {
295 selector_string = para_strcat(selector_string, selectors[i].name);
296 selector_string = para_strcat(selector_string, " ");
298 for (i = 0; senders[i].name; i++) {
299 char *info = senders[i].info();
300 sender_info = para_strcat(sender_info, info);
302 sender_list = para_strcat(sender_list, senders[i].name);
303 sender_list = para_strcat(sender_list, " ");
306 ret = send_va_buffer(fd, "up: %s\nplayed: %u\n"
308 "connections (active/accepted/total): %u/%u/%u\n"
309 "current loglevel: %i\n"
310 "supported audio file selectors: %s\n"
311 "supported audio formats: %s\n"
312 "supported senders: %s\n"
316 mmd->active_connections,
321 supported_audio_formats(),
327 free(selector_string);
334 int com_version(int fd, int argc, __a_unused char **argv)
337 return -E_COMMAND_SYNTAX;
338 return send_buffer(fd, VERSION_TEXT("server")
339 "built: " BUILD_DATE "\n"
340 SYSTEM ", " CC_VERSION "\n"
345 int com_sc(int fd, int argc, char **argv)
348 int ret, old = 0, count = -1; /* print af change forever */
351 count = atoi(argv[1]);
354 if (old != mmd->num_played) {
355 old = mmd->num_played;
356 name = para_strdup(mmd->filename);
360 ret = send_va_buffer(fd, "%s\n", name);
365 if (argc > 1 && !--count)
373 int com_sb(int fd, int argc, char **argv)
376 int ret, nr = -1; /* status bar will be printed that many
377 * times. Negative value means: print
384 sb = get_sb_string(mmd);
386 ret = send_va_buffer(fd, "%s\n", sb);
400 int com_stat(int fd, int argc, char **argv)
402 int ret, num = 0;/* status will be printed that many
403 * times. num <= 0 means: print forever
405 struct misc_meta_data tmp, *nmmd = &tmp;
408 signal(SIGUSR1, dummy);
415 s = get_status(nmmd);
416 ret = send_buffer(fd, s);
425 return -E_SERVER_CRASH;
431 static int send_list_of_commands(int fd, struct server_command *cmd,
436 for (i = 1; cmd->name; cmd++, i++) {
437 char *perms = cmd_perms_itohuman(cmd->perms);
438 ret = send_va_buffer(fd, "%s\t%s\t%s\t%s\n", cmd->name,
449 /* always returns string that must be freed by the caller in handler */
450 static struct server_command *get_cmd_ptr(char *name, char **handler)
452 struct server_command *cmd;
454 for (cmd = server_cmds; cmd->name; cmd++)
455 if (!strcmp(cmd->name, name)) {
457 *handler = para_strdup("para_server"); /* server commands */
460 /* not found, look for commands supported by the current selector */
463 *handler = make_message("the %s selector",
464 selectors[mmd->selector_num].name);
465 cmd = selectors[mmd->selector_num].cmd_list;
467 for (; cmd->name; cmd++)
468 if (!strcmp(cmd->name, name))
474 int com_help(int fd, int argc, char **argv)
476 struct server_command *cmd;
477 char *perms, *handler;
481 /* no argument given, print list of commands */
482 if ((ret = send_list_of_commands(fd, server_cmds, "server")) < 0)
485 handler = para_strdup(selectors[mmd->selector_num].name);
486 cmd = selectors[mmd->selector_num].cmd_list;
488 ret = send_list_of_commands(fd, cmd, handler);
492 /* argument given for help */
493 cmd = get_cmd_ptr(argv[1], &handler);
498 perms = cmd_perms_itohuman(cmd->perms);
499 ret = send_va_buffer(fd,
518 int com_hup(__a_unused int fd, int argc, __a_unused char **argv)
521 return -E_COMMAND_SYNTAX;
522 kill(getppid(), SIGHUP);
527 int com_term(__a_unused int fd, int argc, __a_unused char **argv)
530 return -E_COMMAND_SYNTAX;
531 kill(getppid(), SIGTERM);
535 int com_play(__a_unused int fd, int argc, __a_unused char **argv)
538 return -E_COMMAND_SYNTAX;
540 mmd->new_vss_status_flags |= VSS_PLAYING;
541 mmd->new_vss_status_flags &= ~VSS_NOMORE;
548 int com_stop(__a_unused int fd, int argc, __a_unused char **argv)
551 return -E_COMMAND_SYNTAX;
553 mmd->new_vss_status_flags &= ~VSS_PLAYING;
554 mmd->new_vss_status_flags &= ~VSS_REPOS;
555 mmd->new_vss_status_flags |= VSS_NEXT;
561 int com_pause(__a_unused int fd, int argc, __a_unused char **argv)
564 return -E_COMMAND_SYNTAX;
568 mmd->new_vss_status_flags &= ~VSS_PLAYING;
569 mmd->new_vss_status_flags &= ~VSS_NEXT;
574 int com_chs(int fd, int argc, char **argv)
581 selector = para_strdup(selectors[mmd->selector_num].name);
583 ret = send_va_buffer(fd, "%s\n", selector);
587 for (i = 0; selectors[i].name; i++) {
588 if (strcmp(selectors[i].name, argv[1]))
591 mmd->selector_change = i;
596 return -E_BAD_SELECTOR;
600 int com_next(__a_unused int fd, int argc, __a_unused char **argv)
603 return -E_COMMAND_SYNTAX;
606 mmd->new_vss_status_flags |= VSS_NEXT;
612 int com_nomore(__a_unused int fd, int argc, __a_unused char **argv)
615 return -E_COMMAND_SYNTAX;
617 if (vss_playing() || vss_paused())
618 mmd->new_vss_status_flags |= VSS_NOMORE;
624 int com_ff(__a_unused int fd, int argc, char **argv)
627 int ret, backwards = 0;
632 return -E_COMMAND_SYNTAX;
633 if (!(ret = sscanf(argv[1], "%u%c", &i, &c)))
634 return -E_COMMAND_SYNTAX;
635 if (ret > 1 && c == '-')
636 backwards = 1; /* jmp backwards */
638 ret = -E_NO_AUDIO_FILE;
639 if (!mmd->afi.chunks_total || !mmd->afi.seconds_total)
641 promille = (1000 * mmd->current_chunk) / mmd->afi.chunks_total;
643 promille -= 1000 * i / mmd->afi.seconds_total;
645 promille += 1000 * i / mmd->afi.seconds_total;
648 if (promille > 1000) {
649 mmd->new_vss_status_flags |= VSS_NEXT;
652 mmd->repos_request = (mmd->afi.chunks_total * promille) / 1000;
653 mmd->new_vss_status_flags |= VSS_REPOS;
654 mmd->new_vss_status_flags &= ~VSS_NEXT;
663 int com_jmp(__a_unused int fd, int argc, char **argv)
669 return -E_COMMAND_SYNTAX;
670 if (sscanf(argv[1], "%lu", &i) <= 0)
671 return -E_COMMAND_SYNTAX;
673 ret = -E_NO_AUDIO_FILE;
674 if (!mmd->afi.chunks_total)
678 PARA_INFO_LOG("jumping to %lu%%\n", i);
679 mmd->repos_request = (mmd->afi.chunks_total * i + 50)/ 100;
680 PARA_INFO_LOG("sent: %lu, offset before jmp: %lu\n",
681 mmd->chunks_sent, mmd->offset);
682 mmd->new_vss_status_flags |= VSS_REPOS;
683 mmd->new_vss_status_flags &= ~VSS_NEXT;
692 * check if perms are sufficient to exec a command having perms cmd_perms.
693 * Returns 0 if perms are sufficient, -E_PERM otherwise.
695 static int check_perms(unsigned int perms, struct server_command *cmd_ptr)
697 PARA_DEBUG_LOG("%s", "checking permissions\n");
698 return (cmd_ptr->perms & perms) < cmd_ptr->perms ? -E_PERM : 0;
702 * Parse first string from *cmd and lookup in table of valid commands.
703 * On error, NULL is returned.
705 static struct server_command *parse_cmd(const char *cmdstr)
710 sscanf(cmdstr, "%200s%n", buf, &n);
714 return get_cmd_ptr(buf, NULL);
717 static long int para_rand(long unsigned max)
719 return (long int) ((max + 0.0) * (random() / (RAND_MAX + 1.0)));
722 static void init_rc4_keys(void)
726 for (i = 0; i < 2 * RC4_KEY_LEN; i++)
727 rc4_buf[i] = para_rand(256);
728 PARA_DEBUG_LOG("rc4 keys initialized (%u:%u)\n",
729 (unsigned char) rc4_buf[0],
730 (unsigned char) rc4_buf[RC4_KEY_LEN]);
731 RC4_set_key(&rc4_recv_key, RC4_KEY_LEN, rc4_buf);
732 RC4_set_key(&rc4_send_key, RC4_KEY_LEN, rc4_buf + RC4_KEY_LEN);
735 static void rc4_recv(unsigned long len, const unsigned char *indata,
736 unsigned char *outdata, __a_unused void *private_data)
738 RC4(&rc4_recv_key, len, indata, outdata);
741 static void rc4_send(unsigned long len, const unsigned char *indata,
742 unsigned char *outdata, __a_unused void *private_data)
744 RC4(&rc4_send_key, len, indata, outdata);
747 static int read_command(int fd, char **result)
751 char *command = NULL;
757 ret = recv_buffer(fd, buf, sizeof(buf));
763 ret = -E_COMMAND_SYNTAX;
764 if (command && numbytes + strlen(command) > MAX_COMMAND_LEN) /* DOS */
766 command = para_strcat(command, buf);
767 p = strstr(command, EOC_MSG);
773 ret = command? 1 : -E_COMMAND_SYNTAX;
784 * perform user authentication and execute a command
786 * \param fd the file descriptor to send output to
787 * \param addr socket address info of peer
789 * \return EXIT_SUCCESS or EXIT_FAILURE
791 * Whenever para_server accepts an incoming tcp connection on
792 * the port it listens on, it forks and the resulting child
793 * calls this function.
795 * An RSA-based challenge/response is used to authenticate
796 * the peer. It that authentication succeeds, a random RC4
797 * session key is generated and sent back to the peer,
798 * encrypted with its RSA public key. From this point on,
799 * all transfers are crypted with this session key.
801 * Next it is checked if the peer supplied a valid server
802 * command or a command for the audio file selector currently
803 * in use. If yes, and if the user has sufficient
804 * permissions to execute that command, the function calls
805 * the corresponding command handler which does argument
806 * checking and further processing.
808 * In order to cope with a DOS attacks, a timeout is set up
809 * which terminates the function if the connection was not
810 * authenticated when the timeout expires.
812 * \sa alarm(2), rc4(3), crypt.c, crypt.h
814 int handle_connect(int fd, struct sockaddr_in *addr)
816 int ret, argc, use_rc4 = 0;
818 unsigned char crypt_buf[MAXLINE];
820 struct server_command *cmd = NULL;
821 long unsigned challenge_nr, chall_response;
823 char *p, *command = NULL;
826 signal(SIGCHLD, SIG_IGN);
827 signal(SIGINT, SIG_DFL);
828 signal(SIGTERM, SIG_DFL);
829 signal(SIGHUP, SIG_DFL);
830 signal(SIGUSR1, SIG_IGN);
832 challenge_nr = random();
833 /* send Welcome message */
834 ret = send_va_buffer(fd, "This is para_server, version "
835 PACKAGE_VERSION ".\n" );
838 /* recv auth request line */
839 ret = recv_buffer(fd, buf, sizeof(buf));
848 if (strncmp(buf, "auth ", 5))
851 if (numbytes < 9 || strncmp(buf, "auth rc4 ", 9))
852 p = buf + 5; /* client version < 0.2.6 */
854 p = buf + 9; /* client version >= 0.2.6 */
857 PARA_DEBUG_LOG("received %s request for user %s\n",
858 use_rc4? "rc4" : "auth", p);
863 ret = para_encrypt_challenge(u->rsa, challenge_nr, crypt_buf);
867 PARA_DEBUG_LOG("sending %zu byte challenge\n", numbytes);
868 /* We can't use send_buffer here since buf may contain null bytes */
869 ret = send_bin_buffer(fd,(char *) crypt_buf, numbytes);
872 /* recv decrypted number */
873 ret = recv_buffer(fd, buf, sizeof(buf));
880 if (sscanf(buf, CHALLENGE_RESPONSE_MSG "%lu", &chall_response) < 1
881 || chall_response != challenge_nr)
883 /* auth successful, send 'Proceed' message */
884 PARA_INFO_LOG("good auth for %s (%lu)\n", u->name, challenge_nr);
885 sprintf(buf, "%s", PROCEED_MSG);
888 ret = para_encrypt_buffer(u->rsa, rc4_buf, 2 * RC4_KEY_LEN,
889 (unsigned char *)buf + PROCEED_MSG_LEN + 1);
892 numbytes = ret + strlen(PROCEED_MSG) + 1;
894 numbytes = strlen(buf);
895 ret = send_bin_buffer(fd, buf, numbytes);
899 enable_crypt(fd, rc4_recv, rc4_send, NULL);
900 ret = read_command(fd, &command);
904 cmd = parse_cmd(command);
907 /* valid command, check permissions */
908 ret = check_perms(u->perms, cmd);
911 /* valid command and sufficient perms */
913 argc = split_args(command, &argv, "\n");
917 PARA_NOTICE_LOG("calling com_%s() for %s@%s\n", cmd->name, u->name,
918 inet_ntoa(addr->sin_addr));
919 ret = cmd->handler(fd, argc, argv);
925 PARA_NOTICE_LOG("%s\n", PARA_STRERROR(-ret));
926 if (ret != -E_SEND && ret != -E_RECV)
927 send_va_buffer(fd, "%s\n", PARA_STRERROR(-ret));
933 if (cmd && (cmd->perms & AFS_WRITE) && ret >= 0)
935 mmd->active_connections--;