2 * Copyright (C) 1997-2007 Andre Noll <maan@systemlinux.org>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
19 /** \file command.c does client authentication and executes server commands */
21 #include <sys/time.h> /* gettimeofday */
22 #include "server.cmdline.h"
28 #include <openssl/rc4.h>
34 #include "user_list.h"
35 #include "server_command_list.h"
37 /** commands including options must be shorter than this */
38 #define MAX_COMMAND_LEN 4096
40 static RC4_KEY rc4_recv_key
;
41 static RC4_KEY rc4_send_key
;
42 static unsigned char rc4_buf
[2 * RC4_KEY_LEN
];
44 extern const char *status_item_list
[NUM_STAT_ITEMS
];
45 extern struct misc_meta_data
*mmd
;
46 extern struct audio_file_selector selectors
[];
47 extern struct sender senders
[];
49 static void dummy(__a_unused
int s
)
52 static void mmd_dup(struct misc_meta_data
*new_mmd
)
60 * compute human readable string containing
61 * vss status for given integer value
63 static char *vss_status_tohuman(unsigned int flags
)
65 if (flags
& VSS_PLAYING
)
66 return para_strdup("playing");
67 else if (flags
& VSS_NEXT
)
68 return para_strdup("stopped");
70 return para_strdup("paused");
74 * return human readable permission string. Never returns NULL.
76 static char *cmd_perms_itohuman(unsigned int perms
)
78 char *msg
= para_malloc(5 * sizeof(char));
80 msg
[0] = perms
& AFS_READ
? 'a' : '-';
81 msg
[1] = perms
& AFS_WRITE
? 'A' : '-';
82 msg
[2] = perms
& VSS_READ
? 'v' : '-';
83 msg
[3] = perms
& VSS_WRITE
? 'V' : '-';
91 static char *vss_get_status_flags(unsigned int flags
)
93 char *msg
= para_malloc(5 * sizeof(char));
95 msg
[0] = (flags
& VSS_PLAYING
)? 'P' : '_';
96 msg
[1] = (flags
& VSS_NOMORE
)? 'O' : '_';
97 msg
[2] = (flags
& VSS_NEXT
)? 'N' : '_';
98 msg
[3] = (flags
& VSS_REPOS
)? 'R' : '_';
104 * compute status bar string. Never returns NULL
106 static char *get_sb_string(struct misc_meta_data
*nmmd
)
109 long long unsigned secs
= 0, rsecs
= 0, percent
= 0;
111 base
= para_basename(nmmd
->filename
);
113 return para_strdup("");
116 if (nmmd
->afi
.chunks_total
) {
117 secs
= (long long) nmmd
->afi
.seconds_total
* nmmd
->chunks_sent
118 / nmmd
->afi
.chunks_total
;
119 rsecs
= (long long) nmmd
->afi
.seconds_total
*
120 (nmmd
->afi
.chunks_total
- nmmd
->chunks_sent
)
121 / nmmd
->afi
.chunks_total
;
122 percent
= 100 * ((nmmd
->chunks_sent
+ 5) / 10)
123 / ((nmmd
->afi
.chunks_total
+ 5) / 10);
125 ret
= make_message("%llu:%02llu [%llu:%02llu] (%llu%%) %s",
126 secs
/ 60, secs
% 60,
127 rsecs
/ 60, rsecs
% 60,
135 static char *get_status(struct misc_meta_data
*nmmd
)
137 char *bar
, *ret
, mtime
[30] = "";
138 char *status
, *flags
; /* vss status info */
139 char *ut
= uptime_str();
140 long offset
= (nmmd
->offset
+ 500) / 1000;
144 if (nmmd
->audio_format
>= 0) {
145 localtime_r(&nmmd
->mtime
, &mtime_tm
);
146 strftime(mtime
, 29, "%a %b %d %Y", &mtime_tm
);
148 /* report real status */
149 status
= vss_status_tohuman(nmmd
->vss_status_flags
);
150 flags
= vss_get_status_flags(nmmd
->vss_status_flags
);
151 bar
= para_basename(nmmd
->filename
);
152 gettimeofday(&now
, NULL
);
154 "%s:%zu\n" "%s:%s\n" "%s:%lu\n" "%s:%u\n"
155 "%s:%s\n" "%s:%s\n" "%s:%s\n" "%s:%s\n"
156 "%s:%li\n" "%s:%s\n" "%s" "%s"
157 "%s:%s\n" "%s:%lu.%lu\n" "%s:%lu.%lu\n",
158 status_item_list
[SI_FILE_SIZE
], nmmd
->size
/ 1024,
159 status_item_list
[SI_MTIME
], mtime
,
160 status_item_list
[SI_LENGTH
], nmmd
->afi
.seconds_total
,
161 status_item_list
[SI_NUM_PLAYED
], nmmd
->num_played
,
163 status_item_list
[SI_STATUS_BAR
], bar
? bar
: "(none)",
164 status_item_list
[SI_STATUS
], status
,
165 status_item_list
[SI_STATUS_FLAGS
], flags
,
166 status_item_list
[SI_SELECTOR
], selectors
[nmmd
->selector_num
].name
,
168 status_item_list
[SI_OFFSET
], offset
,
169 status_item_list
[SI_FORMAT
], audio_format_name(nmmd
->audio_format
),
171 nmmd
->afi
.info_string
,
173 status_item_list
[SI_UPTIME
], ut
,
174 status_item_list
[SI_STREAM_START
],
175 (long unsigned)nmmd
->stream_start
.tv_sec
,
176 (long unsigned)nmmd
->stream_start
.tv_usec
,
177 status_item_list
[SI_CURRENT_TIME
],
178 (long unsigned)now
.tv_sec
,
179 (long unsigned)now
.tv_usec
189 static int check_sender_args(int argc
, char **argv
, struct sender_command_data
*scd
)
192 /* this has to match sender.h */
193 const char *subcmds
[] = {"add", "delete", "allow", "deny", "on", "off", NULL
};
195 scd
->sender_num
= -1;
197 return -E_COMMAND_SYNTAX
;
198 for (i
= 0; senders
[i
].name
; i
++)
199 if (!strcmp(senders
[i
].name
, argv
[1]))
201 PARA_DEBUG_LOG("%d:%s\n", argc
, argv
[1]);
202 if (!senders
[i
].name
)
203 return -E_COMMAND_SYNTAX
;
205 for (i
= 0; subcmds
[i
]; i
++)
206 if (!strcmp(subcmds
[i
], argv
[2]))
209 return -E_COMMAND_SYNTAX
;
212 if (!senders
[scd
->sender_num
].client_cmds
[scd
->cmd_num
]) {
214 return -E_SENDER_CMD
;
217 switch (scd
->cmd_num
) {
221 return -E_COMMAND_SYNTAX
;
225 if (argc
!= 4 && argc
!= 5)
226 return -E_COMMAND_SYNTAX
;
227 if (!inet_aton(argv
[3], &scd
->addr
))
228 return -E_COMMAND_SYNTAX
;
231 scd
->netmask
= atoi(argv
[4]);
232 if (scd
->netmask
< 0 || scd
->netmask
> 32)
233 return -E_COMMAND_SYNTAX
;
238 if (argc
!= 4 && argc
!= 5)
239 return -E_COMMAND_SYNTAX
;
240 if (!inet_aton(argv
[3], &scd
->addr
))
241 return -E_COMMAND_SYNTAX
;
244 scd
->port
= atoi(argv
[4]);
245 if (scd
->port
< 0 || scd
->port
> 65535)
246 return -E_COMMAND_SYNTAX
;
250 return -E_COMMAND_SYNTAX
;
255 int com_sender(int fd
, int argc
, char **argv
)
258 struct sender_command_data scd
;
262 for (i
= 0; senders
[i
].name
; i
++) {
263 char *tmp
= make_message("%s%s\n",
264 msg
? msg
: "", senders
[i
].name
);
268 ret
= send_buffer(fd
, msg
);
272 ret
= check_sender_args(argc
, argv
, &scd
);
275 if (scd
.sender_num
< 0)
277 msg
= senders
[scd
.sender_num
].help();
278 send_buffer(fd
, msg
);
282 for (i
= 0; i
< 10; i
++) {
284 if (mmd
->sender_cmd_data
.cmd_num
>= 0) {
289 mmd
->sender_cmd_data
= scd
;
293 return (i
< 10)? 1 : -E_LOCK
;
297 int com_si(int fd
, int argc
, __a_unused
char **argv
)
301 char *selector_string
= NULL
, *sender_info
= NULL
, *sender_list
= NULL
;
304 return -E_COMMAND_SYNTAX
;
306 for (i
= 0; selectors
[i
].name
; i
++) {
307 selector_string
= para_strcat(selector_string
, selectors
[i
].name
);
308 selector_string
= para_strcat(selector_string
, " ");
310 for (i
= 0; senders
[i
].name
; i
++) {
311 char *info
= senders
[i
].info();
312 sender_info
= para_strcat(sender_info
, info
);
314 sender_list
= para_strcat(sender_list
, senders
[i
].name
);
315 sender_list
= para_strcat(sender_list
, " ");
318 ret
= send_va_buffer(fd
, "up: %s\nplayed: %u\n"
320 "connections (active/accepted/total): %u/%u/%u\n"
321 "current loglevel: %i\n"
322 "supported audio file selectors: %s\n"
323 "supported audio formats: %s\n"
324 "supported senders: %s\n"
328 mmd
->active_connections
,
333 supported_audio_formats(),
339 free(selector_string
);
346 int com_version(int fd
, int argc
, __a_unused
char **argv
)
349 return -E_COMMAND_SYNTAX
;
350 return send_buffer(fd
, VERSION_TEXT("server")
351 "built: " BUILD_DATE
"\n"
352 SYSTEM
", " CC_VERSION
"\n"
357 int com_sc(int fd
, int argc
, char **argv
)
360 int ret
, old
= 0, count
= -1; /* print af change forever */
363 count
= atoi(argv
[1]);
366 if (old
!= mmd
->num_played
) {
367 old
= mmd
->num_played
;
368 name
= para_strdup(mmd
->filename
);
372 ret
= send_va_buffer(fd
, "%s\n", name
);
377 if (argc
> 1 && !--count
)
385 int com_sb(int fd
, int argc
, char **argv
)
388 int ret
, nr
= -1; /* status bar will be printed that many
389 * times. Negative value means: print
396 sb
= get_sb_string(mmd
);
398 ret
= send_va_buffer(fd
, "%s\n", sb
);
412 int com_stat(int fd
, int argc
, char **argv
)
414 int ret
, num
= 0;/* status will be printed that many
415 * times. num <= 0 means: print forever
417 struct misc_meta_data tmp
, *nmmd
= &tmp
;
420 signal(SIGUSR1
, dummy
);
427 s
= get_status(nmmd
);
428 ret
= send_buffer(fd
, s
);
437 return -E_SERVER_CRASH
;
443 static int send_list_of_commands(int fd
, struct server_command
*cmd
,
448 for (i
= 1; cmd
->name
; cmd
++, i
++) {
449 char *perms
= cmd_perms_itohuman(cmd
->perms
);
450 ret
= send_va_buffer(fd
, "%s\t%s\t%s\t%s\n", cmd
->name
,
461 /* always returns string that must be freed by the caller in handler */
462 static struct server_command
*get_cmd_ptr(char *name
, char **handler
)
464 struct server_command
*cmd
;
466 for (cmd
= server_cmds
; cmd
->name
; cmd
++)
467 if (!strcmp(cmd
->name
, name
)) {
469 *handler
= para_strdup("para_server"); /* server commands */
472 /* not found, look for commands supported by the current selector */
475 *handler
= make_message("the %s selector",
476 selectors
[mmd
->selector_num
].name
);
477 cmd
= selectors
[mmd
->selector_num
].cmd_list
;
479 for (; cmd
->name
; cmd
++)
480 if (!strcmp(cmd
->name
, name
))
486 int com_help(int fd
, int argc
, char **argv
)
488 struct server_command
*cmd
;
489 char *perms
, *handler
;
493 /* no argument given, print list of commands */
494 if ((ret
= send_list_of_commands(fd
, server_cmds
, "server")) < 0)
497 handler
= para_strdup(selectors
[mmd
->selector_num
].name
);
498 cmd
= selectors
[mmd
->selector_num
].cmd_list
;
500 ret
= send_list_of_commands(fd
, cmd
, handler
);
504 /* argument given for help */
505 cmd
= get_cmd_ptr(argv
[1], &handler
);
510 perms
= cmd_perms_itohuman(cmd
->perms
);
511 ret
= send_va_buffer(fd
,
530 int com_hup(__a_unused
int fd
, int argc
, __a_unused
char **argv
)
533 return -E_COMMAND_SYNTAX
;
534 kill(getppid(), SIGHUP
);
539 int com_term(__a_unused
int fd
, int argc
, __a_unused
char **argv
)
542 return -E_COMMAND_SYNTAX
;
543 kill(getppid(), SIGTERM
);
547 int com_play(__a_unused
int fd
, int argc
, __a_unused
char **argv
)
550 return -E_COMMAND_SYNTAX
;
552 mmd
->new_vss_status_flags
|= VSS_PLAYING
;
553 mmd
->new_vss_status_flags
&= ~VSS_NOMORE
;
560 int com_stop(__a_unused
int fd
, int argc
, __a_unused
char **argv
)
563 return -E_COMMAND_SYNTAX
;
565 mmd
->new_vss_status_flags
&= ~VSS_PLAYING
;
566 mmd
->new_vss_status_flags
&= ~VSS_REPOS
;
567 mmd
->new_vss_status_flags
|= VSS_NEXT
;
573 int com_pause(__a_unused
int fd
, int argc
, __a_unused
char **argv
)
576 return -E_COMMAND_SYNTAX
;
580 mmd
->new_vss_status_flags
&= ~VSS_PLAYING
;
581 mmd
->new_vss_status_flags
&= ~VSS_NEXT
;
586 int com_chs(int fd
, int argc
, char **argv
)
593 selector
= para_strdup(selectors
[mmd
->selector_num
].name
);
595 ret
= send_va_buffer(fd
, "%s\n", selector
);
599 for (i
= 0; selectors
[i
].name
; i
++) {
600 if (strcmp(selectors
[i
].name
, argv
[1]))
603 mmd
->selector_change
= i
;
608 return -E_BAD_SELECTOR
;
612 int com_next(__a_unused
int fd
, int argc
, __a_unused
char **argv
)
615 return -E_COMMAND_SYNTAX
;
618 mmd
->new_vss_status_flags
|= VSS_NEXT
;
624 int com_nomore(__a_unused
int fd
, int argc
, __a_unused
char **argv
)
627 return -E_COMMAND_SYNTAX
;
629 if (vss_playing() || vss_paused())
630 mmd
->new_vss_status_flags
|= VSS_NOMORE
;
636 int com_ff(__a_unused
int fd
, int argc
, char **argv
)
639 int ret
, backwards
= 0;
644 return -E_COMMAND_SYNTAX
;
645 if (!(ret
= sscanf(argv
[1], "%u%c", &i
, &c
)))
646 return -E_COMMAND_SYNTAX
;
647 if (ret
> 1 && c
== '-')
648 backwards
= 1; /* jmp backwards */
650 ret
= -E_NO_AUDIO_FILE
;
651 if (!mmd
->afi
.chunks_total
|| !mmd
->afi
.seconds_total
)
653 promille
= (1000 * mmd
->current_chunk
) / mmd
->afi
.chunks_total
;
655 promille
-= 1000 * i
/ mmd
->afi
.seconds_total
;
657 promille
+= 1000 * i
/ mmd
->afi
.seconds_total
;
660 if (promille
> 1000) {
661 mmd
->new_vss_status_flags
|= VSS_NEXT
;
664 mmd
->repos_request
= (mmd
->afi
.chunks_total
* promille
) / 1000;
665 mmd
->new_vss_status_flags
|= VSS_REPOS
;
666 mmd
->new_vss_status_flags
&= ~VSS_NEXT
;
675 int com_jmp(__a_unused
int fd
, int argc
, char **argv
)
681 return -E_COMMAND_SYNTAX
;
682 if (sscanf(argv
[1], "%lu", &i
) <= 0)
683 return -E_COMMAND_SYNTAX
;
685 ret
= -E_NO_AUDIO_FILE
;
686 if (!mmd
->afi
.chunks_total
)
690 PARA_INFO_LOG("jumping to %lu%%\n", i
);
691 mmd
->repos_request
= (mmd
->afi
.chunks_total
* i
+ 50)/ 100;
692 PARA_INFO_LOG("sent: %lu, offset before jmp: %lu\n",
693 mmd
->chunks_sent
, mmd
->offset
);
694 mmd
->new_vss_status_flags
|= VSS_REPOS
;
695 mmd
->new_vss_status_flags
&= ~VSS_NEXT
;
704 * check if perms are sufficient to exec a command having perms cmd_perms.
705 * Returns 0 if perms are sufficient, -E_PERM otherwise.
707 static int check_perms(unsigned int perms
, struct server_command
*cmd_ptr
)
709 PARA_DEBUG_LOG("%s", "checking permissions\n");
710 return (cmd_ptr
->perms
& perms
) < cmd_ptr
->perms
? -E_PERM
: 0;
714 * Parse first string from *cmd and lookup in table of valid commands.
715 * On error, NULL is returned.
717 static struct server_command
*parse_cmd(const char *cmdstr
)
722 sscanf(cmdstr
, "%200s%n", buf
, &n
);
726 return get_cmd_ptr(buf
, NULL
);
729 static long int para_rand(long unsigned max
)
731 return (long int) ((max
+ 0.0) * (random() / (RAND_MAX
+ 1.0)));
734 static void init_rc4_keys(void)
738 for (i
= 0; i
< 2 * RC4_KEY_LEN
; i
++)
739 rc4_buf
[i
] = para_rand(256);
740 PARA_DEBUG_LOG("rc4 keys initialized (%u:%u)\n",
741 (unsigned char) rc4_buf
[0],
742 (unsigned char) rc4_buf
[RC4_KEY_LEN
]);
743 RC4_set_key(&rc4_recv_key
, RC4_KEY_LEN
, rc4_buf
);
744 RC4_set_key(&rc4_send_key
, RC4_KEY_LEN
, rc4_buf
+ RC4_KEY_LEN
);
747 static void rc4_recv(unsigned long len
, const unsigned char *indata
,
748 unsigned char *outdata
, __a_unused
void *private_data
)
750 RC4(&rc4_recv_key
, len
, indata
, outdata
);
753 static void rc4_send(unsigned long len
, const unsigned char *indata
,
754 unsigned char *outdata
, __a_unused
void *private_data
)
756 RC4(&rc4_send_key
, len
, indata
, outdata
);
759 static int read_command(int fd
, char **result
)
763 char *command
= NULL
;
769 ret
= recv_buffer(fd
, buf
, sizeof(buf
));
775 ret
= -E_COMMAND_SYNTAX
;
776 if (command
&& numbytes
+ strlen(command
) > MAX_COMMAND_LEN
) /* DOS */
778 command
= para_strcat(command
, buf
);
779 p
= strstr(command
, EOC_MSG
);
785 ret
= command
? 1 : -E_COMMAND_SYNTAX
;
796 * perform user authentication and execute a command
798 * \param fd the file descriptor to send output to
799 * \param addr socket address info of peer
801 * \return EXIT_SUCCESS or EXIT_FAILURE
803 * Whenever para_server accepts an incoming tcp connection on
804 * the port it listens on, it forks and the resulting child
805 * calls this function.
807 * An RSA-based challenge/response is used to authenticate
808 * the peer. It that authentication succeeds, a random RC4
809 * session key is generated and sent back to the peer,
810 * encrypted with its RSA public key. From this point on,
811 * all transfers are crypted with this session key.
813 * Next it is checked if the peer supplied a valid server
814 * command or a command for the audio file selector currently
815 * in use. If yes, and if the user has sufficient
816 * permissions to execute that command, the function calls
817 * the corresponding command handler which does argument
818 * checking and further processing.
820 * In order to cope with a DOS attacks, a timeout is set up
821 * which terminates the function if the connection was not
822 * authenticated when the timeout expires.
824 * \sa alarm(2), rc4(3), crypt.c, crypt.h
826 int handle_connect(int fd
, struct sockaddr_in
*addr
)
828 int ret
, argc
, use_rc4
= 0;
830 unsigned char crypt_buf
[MAXLINE
];
832 struct server_command
*cmd
= NULL
;
833 long unsigned challenge_nr
, chall_response
;
835 char *p
, *command
= NULL
;
838 signal(SIGCHLD
, SIG_IGN
);
839 signal(SIGINT
, SIG_DFL
);
840 signal(SIGTERM
, SIG_DFL
);
841 signal(SIGHUP
, SIG_DFL
);
842 signal(SIGUSR1
, SIG_IGN
);
844 challenge_nr
= random();
845 /* send Welcome message */
846 ret
= send_va_buffer(fd
, "This is para_server, version "
847 PACKAGE_VERSION
".\n" );
850 /* recv auth request line */
851 ret
= recv_buffer(fd
, buf
, sizeof(buf
));
860 if (strncmp(buf
, "auth ", 5))
863 if (numbytes
< 9 || strncmp(buf
, "auth rc4 ", 9))
864 p
= buf
+ 5; /* client version < 0.2.6 */
866 p
= buf
+ 9; /* client version >= 0.2.6 */
869 PARA_DEBUG_LOG("received %s request for user %s\n",
870 use_rc4
? "rc4" : "auth", p
);
875 ret
= para_encrypt_challenge(u
->rsa
, challenge_nr
, crypt_buf
);
879 PARA_DEBUG_LOG("sending %d byte challenge\n", numbytes
);
880 /* We can't use send_buffer here since buf may contain null bytes */
881 ret
= send_bin_buffer(fd
,(char *) crypt_buf
, numbytes
);
884 /* recv decrypted number */
885 ret
= recv_buffer(fd
, buf
, sizeof(buf
));
892 if (sscanf(buf
, CHALLENGE_RESPONSE_MSG
"%lu", &chall_response
) < 1
893 || chall_response
!= challenge_nr
)
895 /* auth successful, send 'Proceed' message */
896 PARA_INFO_LOG("good auth for %s (%lu)\n", u
->name
, challenge_nr
);
897 sprintf(buf
, "%s", PROCEED_MSG
);
900 ret
= para_encrypt_buffer(u
->rsa
, rc4_buf
, 2 * RC4_KEY_LEN
,
901 (unsigned char *)buf
+ PROCEED_MSG_LEN
+ 1);
904 numbytes
= ret
+ strlen(PROCEED_MSG
) + 1;
906 numbytes
= strlen(buf
);
907 ret
= send_bin_buffer(fd
, buf
, numbytes
);
911 enable_crypt(fd
, rc4_recv
, rc4_send
, NULL
);
912 ret
= read_command(fd
, &command
);
916 cmd
= parse_cmd(command
);
919 /* valid command, check permissions */
920 ret
= check_perms(u
->perms
, cmd
);
923 /* valid command and sufficient perms */
925 argc
= split_args(command
, &argv
, "\n");
929 PARA_NOTICE_LOG("calling com_%s() for %s@%s\n", cmd
->name
, u
->name
,
930 inet_ntoa(addr
->sin_addr
));
931 ret
= cmd
->handler(fd
, argc
, argv
);
937 PARA_NOTICE_LOG("%s\n", PARA_STRERROR(-ret
));
938 if (ret
!= -E_SEND
&& ret
!= -E_RECV
)
939 send_va_buffer(fd
, "%s\n", PARA_STRERROR(-ret
));
945 if (cmd
&& (cmd
->perms
& AFS_WRITE
) && ret
>= 0)
947 mmd
->active_connections
--;