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"
29 #include "user_list.h"
30 #include "server_command_list.h"
31 #include "afs_command_list.h"
33 /** commands including options must be shorter than this */
34 #define MAX_COMMAND_LEN 32768
36 static RC4_KEY rc4_recv_key
;
37 static RC4_KEY rc4_send_key
;
38 static unsigned char rc4_buf
[2 * RC4_KEY_LEN
];
40 extern const char *status_item_list
[NUM_STAT_ITEMS
];
41 extern struct misc_meta_data
*mmd
;
42 extern struct sender senders
[];
44 static void dummy(__a_unused
int s
)
47 static void mmd_dup(struct misc_meta_data
*new_mmd
)
55 * compute human readable string containing
56 * vss status for given integer value
58 static char *vss_status_tohuman(unsigned int flags
)
60 if (flags
& VSS_PLAYING
)
61 return para_strdup("playing");
62 else if (flags
& VSS_NEXT
)
63 return para_strdup("stopped");
65 return para_strdup("paused");
69 * return human readable permission string. Never returns NULL.
71 static char *cmd_perms_itohuman(unsigned int perms
)
73 char *msg
= para_malloc(5 * sizeof(char));
75 msg
[0] = perms
& AFS_READ
? 'a' : '-';
76 msg
[1] = perms
& AFS_WRITE
? 'A' : '-';
77 msg
[2] = perms
& VSS_READ
? 'v' : '-';
78 msg
[3] = perms
& VSS_WRITE
? 'V' : '-';
86 static char *vss_get_status_flags(unsigned int flags
)
88 char *msg
= para_malloc(5 * sizeof(char));
90 msg
[0] = (flags
& VSS_PLAYING
)? 'P' : '_';
91 msg
[1] = (flags
& VSS_NOMORE
)? 'O' : '_';
92 msg
[2] = (flags
& VSS_NEXT
)? 'N' : '_';
93 msg
[3] = (flags
& VSS_REPOS
)? 'R' : '_';
99 * compute status bar string. Never returns NULL
101 static char *get_sb_string(struct misc_meta_data
*nmmd
)
104 long long unsigned secs
= 0, rsecs
= 0, percent
= 0;
106 base
= para_basename(nmmd
->filename
);
108 return para_strdup("");
111 if (nmmd
->afi
.chunks_total
) {
112 secs
= (long long) nmmd
->afi
.seconds_total
* nmmd
->chunks_sent
113 / nmmd
->afi
.chunks_total
;
114 rsecs
= (long long) nmmd
->afi
.seconds_total
*
115 (nmmd
->afi
.chunks_total
- nmmd
->chunks_sent
)
116 / nmmd
->afi
.chunks_total
;
117 percent
= 100 * ((nmmd
->chunks_sent
+ 5) / 10)
118 / ((nmmd
->afi
.chunks_total
+ 5) / 10);
120 ret
= make_message("%llu:%02llu [%llu:%02llu] (%llu%%) %s",
121 secs
/ 60, secs
% 60,
122 rsecs
/ 60, rsecs
% 60,
130 static char *get_status(struct misc_meta_data
*nmmd
)
132 char *bar
, *ret
, mtime
[30] = "";
133 char *status
, *flags
; /* vss status info */
134 char *ut
= uptime_str();
135 long offset
= (nmmd
->offset
+ 500) / 1000;
139 if (nmmd
->audio_format
>= 0) {
140 localtime_r(&nmmd
->mtime
, &mtime_tm
);
141 strftime(mtime
, 29, "%a %b %d %Y", &mtime_tm
);
143 /* report real status */
144 status
= vss_status_tohuman(nmmd
->vss_status_flags
);
145 flags
= vss_get_status_flags(nmmd
->vss_status_flags
);
146 bar
= para_basename(nmmd
->filename
);
147 gettimeofday(&now
, NULL
);
149 "%s:%zu\n" "%s:%s\n" "%s:%lu\n" "%s:%u\n"
150 "%s:%s\n" "%s:%s\n" "%s:%s\n" "%s:%s\n"
151 "%s:%li\n" "%s:%s\n" "%s"
152 "%s:%s\n" "%s:%lu.%lu\n" "%s:%lu.%lu\n",
153 status_item_list
[SI_FILE_SIZE
], nmmd
->size
/ 1024,
154 status_item_list
[SI_MTIME
], mtime
,
155 status_item_list
[SI_LENGTH
], nmmd
->afi
.seconds_total
,
156 status_item_list
[SI_NUM_PLAYED
], nmmd
->num_played
,
158 status_item_list
[SI_STATUS_BAR
], bar
? bar
: "(none)",
159 status_item_list
[SI_STATUS
], status
,
160 status_item_list
[SI_STATUS_FLAGS
], flags
,
161 status_item_list
[SI_SELECTOR
], "FIXME",
163 status_item_list
[SI_OFFSET
], offset
,
164 status_item_list
[SI_FORMAT
], audio_format_name(nmmd
->audio_format
),
165 nmmd
->afi
.info_string
,
167 status_item_list
[SI_UPTIME
], ut
,
168 status_item_list
[SI_STREAM_START
],
169 (long unsigned)nmmd
->stream_start
.tv_sec
,
170 (long unsigned)nmmd
->stream_start
.tv_usec
,
171 status_item_list
[SI_CURRENT_TIME
],
172 (long unsigned)now
.tv_sec
,
173 (long unsigned)now
.tv_usec
183 static int check_sender_args(int argc
, char * const * argv
, struct sender_command_data
*scd
)
186 /* this has to match sender.h */
187 const char *subcmds
[] = {"add", "delete", "allow", "deny", "on", "off", NULL
};
189 scd
->sender_num
= -1;
191 return -E_COMMAND_SYNTAX
;
192 for (i
= 0; senders
[i
].name
; i
++)
193 if (!strcmp(senders
[i
].name
, argv
[1]))
195 PARA_DEBUG_LOG("%d:%s\n", argc
, argv
[1]);
196 if (!senders
[i
].name
)
197 return -E_COMMAND_SYNTAX
;
199 for (i
= 0; subcmds
[i
]; i
++)
200 if (!strcmp(subcmds
[i
], argv
[2]))
203 return -E_COMMAND_SYNTAX
;
206 if (!senders
[scd
->sender_num
].client_cmds
[scd
->cmd_num
]) {
208 return -E_SENDER_CMD
;
211 switch (scd
->cmd_num
) {
215 return -E_COMMAND_SYNTAX
;
219 if (argc
!= 4 && argc
!= 5)
220 return -E_COMMAND_SYNTAX
;
221 if (!inet_pton(AF_INET
, argv
[3], &scd
->addr
))
222 return -E_COMMAND_SYNTAX
;
225 scd
->netmask
= atoi(argv
[4]);
226 if (scd
->netmask
< 0 || scd
->netmask
> 32)
227 return -E_COMMAND_SYNTAX
;
232 if (argc
!= 4 && argc
!= 5)
233 return -E_COMMAND_SYNTAX
;
234 if (!inet_pton(AF_INET
, argv
[3], &scd
->addr
))
235 return -E_COMMAND_SYNTAX
;
238 scd
->port
= atoi(argv
[4]);
239 if (scd
->port
< 0 || scd
->port
> 65535)
240 return -E_COMMAND_SYNTAX
;
244 return -E_COMMAND_SYNTAX
;
249 int com_sender(int fd
, int argc
, char * const * argv
)
252 struct sender_command_data scd
;
256 for (i
= 0; senders
[i
].name
; i
++) {
257 char *tmp
= make_message("%s%s\n",
258 msg
? msg
: "", senders
[i
].name
);
262 ret
= send_buffer(fd
, msg
);
266 ret
= check_sender_args(argc
, argv
, &scd
);
269 if (scd
.sender_num
< 0)
271 msg
= senders
[scd
.sender_num
].help();
272 send_buffer(fd
, msg
);
276 for (i
= 0; i
< 10; i
++) {
278 if (mmd
->sender_cmd_data
.cmd_num
>= 0) {
283 mmd
->sender_cmd_data
= scd
;
287 return (i
< 10)? 1 : -E_LOCK
;
291 int com_si(int fd
, int argc
, __a_unused
char * const * argv
)
295 char *sender_info
= NULL
, *sender_list
= NULL
;
298 return -E_COMMAND_SYNTAX
;
300 for (i
= 0; senders
[i
].name
; i
++) {
301 char *info
= senders
[i
].info();
302 sender_info
= para_strcat(sender_info
, info
);
304 sender_list
= para_strcat(sender_list
, senders
[i
].name
);
305 sender_list
= para_strcat(sender_list
, " ");
308 ret
= send_va_buffer(fd
, "up: %s\nplayed: %u\n"
310 "connections (active/accepted/total): %u/%u/%u\n"
311 "current loglevel: %i\n"
312 "supported audio formats: %s\n"
313 "supported senders: %s\n"
317 mmd
->active_connections
,
321 supported_audio_formats(),
333 int com_version(int fd
, int argc
, __a_unused
char * const * argv
)
336 return -E_COMMAND_SYNTAX
;
337 return send_buffer(fd
, VERSION_TEXT("server")
338 "built: " BUILD_DATE
"\n"
339 SYSTEM
", " CC_VERSION
"\n"
344 int com_sc(int fd
, int argc
, char * const * argv
)
347 int ret
, old
= 0, count
= -1; /* print af change forever */
350 count
= atoi(argv
[1]);
353 if (old
!= mmd
->num_played
) {
354 old
= mmd
->num_played
;
355 name
= para_strdup(mmd
->filename
);
359 ret
= send_va_buffer(fd
, "%s\n", name
);
364 if (argc
> 1 && !--count
)
372 int com_sb(int fd
, int argc
, char * const * argv
)
375 int ret
, nr
= -1; /* status bar will be printed that many
376 * times. Negative value means: print
383 sb
= get_sb_string(mmd
);
385 ret
= send_va_buffer(fd
, "%s\n", sb
);
399 int com_stat(int fd
, int argc
, char * const * argv
)
401 int ret
, num
= 0;/* status will be printed that many
402 * times. num <= 0 means: print forever
404 struct misc_meta_data tmp
, *nmmd
= &tmp
;
407 signal(SIGUSR1
, dummy
);
414 s
= get_status(nmmd
);
415 ret
= send_buffer(fd
, s
);
424 return -E_SERVER_CRASH
;
430 static int send_list_of_commands(int fd
, struct server_command
*cmd
,
435 for (i
= 1; cmd
->name
; cmd
++, i
++) {
436 char *perms
= cmd_perms_itohuman(cmd
->perms
);
437 ret
= send_va_buffer(fd
, "%s\t%s\t%s\t%s\n", cmd
->name
,
448 /* always returns string that must be freed by the caller in handler */
449 static struct server_command
*get_cmd_ptr(const char *name
, char **handler
)
451 struct server_command
*cmd
;
453 for (cmd
= server_cmds
; cmd
->name
; cmd
++)
454 if (!strcmp(cmd
->name
, name
)) {
456 *handler
= para_strdup("para_server"); /* server commands */
459 /* not found, look for commands supported by afs */
460 for (cmd
= afs_cmds
; cmd
->name
; cmd
++)
461 if (!strcmp(cmd
->name
, name
))
467 int com_help(int fd
, int argc
, char * const * argv
)
469 struct server_command
*cmd
;
470 char *perms
, *handler
;
474 /* no argument given, print list of commands */
475 if ((ret
= send_list_of_commands(fd
, server_cmds
, "server")) < 0)
477 return send_list_of_commands(fd
, afs_cmds
, "afs");
479 /* argument given for help */
480 cmd
= get_cmd_ptr(argv
[1], &handler
);
485 perms
= cmd_perms_itohuman(cmd
->perms
);
486 ret
= send_va_buffer(fd
,
505 int com_hup(__a_unused
int fd
, int argc
, __a_unused
char * const * argv
)
508 return -E_COMMAND_SYNTAX
;
509 kill(getppid(), SIGHUP
);
514 int com_term(__a_unused
int fd
, int argc
, __a_unused
char * const * argv
)
517 return -E_COMMAND_SYNTAX
;
518 kill(getppid(), SIGTERM
);
522 int com_play(__a_unused
int fd
, int argc
, __a_unused
char * const * argv
)
525 return -E_COMMAND_SYNTAX
;
527 mmd
->new_vss_status_flags
|= VSS_PLAYING
;
528 mmd
->new_vss_status_flags
&= ~VSS_NOMORE
;
535 int com_stop(__a_unused
int fd
, int argc
, __a_unused
char * const * argv
)
538 return -E_COMMAND_SYNTAX
;
540 mmd
->new_vss_status_flags
&= ~VSS_PLAYING
;
541 mmd
->new_vss_status_flags
&= ~VSS_REPOS
;
542 mmd
->new_vss_status_flags
|= VSS_NEXT
;
548 int com_pause(__a_unused
int fd
, int argc
, __a_unused
char * const * argv
)
551 return -E_COMMAND_SYNTAX
;
555 mmd
->new_vss_status_flags
&= ~VSS_PLAYING
;
556 mmd
->new_vss_status_flags
&= ~VSS_NEXT
;
562 int com_next(__a_unused
int fd
, int argc
, __a_unused
char * const * argv
)
565 return -E_COMMAND_SYNTAX
;
568 mmd
->new_vss_status_flags
|= VSS_NEXT
;
574 int com_nomore(__a_unused
int fd
, int argc
, __a_unused
char * const * argv
)
577 return -E_COMMAND_SYNTAX
;
579 if (vss_playing() || vss_paused())
580 mmd
->new_vss_status_flags
|= VSS_NOMORE
;
586 int com_ff(__a_unused
int fd
, int argc
, char * const * argv
)
589 int ret
, backwards
= 0;
594 return -E_COMMAND_SYNTAX
;
595 if (!(ret
= sscanf(argv
[1], "%u%c", &i
, &c
)))
596 return -E_COMMAND_SYNTAX
;
597 if (ret
> 1 && c
== '-')
598 backwards
= 1; /* jmp backwards */
600 ret
= -E_NO_AUDIO_FILE
;
601 if (!mmd
->afi
.chunks_total
|| !mmd
->afi
.seconds_total
)
603 promille
= (1000 * mmd
->current_chunk
) / mmd
->afi
.chunks_total
;
605 promille
-= 1000 * i
/ mmd
->afi
.seconds_total
;
607 promille
+= 1000 * i
/ mmd
->afi
.seconds_total
;
610 if (promille
> 1000) {
611 mmd
->new_vss_status_flags
|= VSS_NEXT
;
614 mmd
->repos_request
= (mmd
->afi
.chunks_total
* promille
) / 1000;
615 mmd
->new_vss_status_flags
|= VSS_REPOS
;
616 mmd
->new_vss_status_flags
&= ~VSS_NEXT
;
625 int com_jmp(__a_unused
int fd
, int argc
, char * const * argv
)
631 return -E_COMMAND_SYNTAX
;
632 if (sscanf(argv
[1], "%lu", &i
) <= 0)
633 return -E_COMMAND_SYNTAX
;
635 ret
= -E_NO_AUDIO_FILE
;
636 if (!mmd
->afi
.chunks_total
)
640 PARA_INFO_LOG("jumping to %lu%%\n", i
);
641 mmd
->repos_request
= (mmd
->afi
.chunks_total
* i
+ 50)/ 100;
642 PARA_INFO_LOG("sent: %lu, offset before jmp: %lu\n",
643 mmd
->chunks_sent
, mmd
->offset
);
644 mmd
->new_vss_status_flags
|= VSS_REPOS
;
645 mmd
->new_vss_status_flags
&= ~VSS_NEXT
;
654 * check if perms are sufficient to exec a command having perms cmd_perms.
655 * Returns 0 if perms are sufficient, -E_PERM otherwise.
657 static int check_perms(unsigned int perms
, struct server_command
*cmd_ptr
)
659 PARA_DEBUG_LOG("%s", "checking permissions\n");
660 return (cmd_ptr
->perms
& perms
) < cmd_ptr
->perms
? -E_PERM
: 0;
664 * Parse first string from *cmd and lookup in table of valid commands.
665 * On error, NULL is returned.
667 static struct server_command
*parse_cmd(const char *cmdstr
)
672 sscanf(cmdstr
, "%200s%n", buf
, &n
);
676 return get_cmd_ptr(buf
, NULL
);
679 static long int para_rand(long unsigned max
)
681 return (long int) ((max
+ 0.0) * (random() / (RAND_MAX
+ 1.0)));
684 static void init_rc4_keys(void)
688 for (i
= 0; i
< 2 * RC4_KEY_LEN
; i
++)
689 rc4_buf
[i
] = para_rand(256);
690 PARA_DEBUG_LOG("rc4 keys initialized (%u:%u)\n",
691 (unsigned char) rc4_buf
[0],
692 (unsigned char) rc4_buf
[RC4_KEY_LEN
]);
693 RC4_set_key(&rc4_recv_key
, RC4_KEY_LEN
, rc4_buf
);
694 RC4_set_key(&rc4_send_key
, RC4_KEY_LEN
, rc4_buf
+ RC4_KEY_LEN
);
697 static void rc4_recv(unsigned long len
, const unsigned char *indata
,
698 unsigned char *outdata
, __a_unused
void *private_data
)
700 RC4(&rc4_recv_key
, len
, indata
, outdata
);
703 static void rc4_send(unsigned long len
, const unsigned char *indata
,
704 unsigned char *outdata
, __a_unused
void *private_data
)
706 RC4(&rc4_send_key
, len
, indata
, outdata
);
709 static int read_command(int fd
, char **result
)
713 char *command
= NULL
;
719 ret
= recv_buffer(fd
, buf
, sizeof(buf
));
725 ret
= -E_COMMAND_SYNTAX
;
726 if (command
&& numbytes
+ strlen(command
) > MAX_COMMAND_LEN
) /* DOS */
728 command
= para_strcat(command
, buf
);
729 p
= strstr(command
, EOC_MSG
);
735 ret
= command
? 1 : -E_COMMAND_SYNTAX
;
746 * perform user authentication and execute a command
748 * \param fd the file descriptor to send output to
749 * \param addr socket address info of peer
751 * \return EXIT_SUCCESS or EXIT_FAILURE
753 * Whenever para_server accepts an incoming tcp connection on
754 * the port it listens on, it forks and the resulting child
755 * calls this function.
757 * An RSA-based challenge/response is used to authenticate
758 * the peer. It that authentication succeeds, a random RC4
759 * session key is generated and sent back to the peer,
760 * encrypted with its RSA public key. From this point on,
761 * all transfers are crypted with this session key.
763 * Next it is checked if the peer supplied a valid server command or a command
764 * for the audio file selector. If yes, and if the user has sufficient
765 * permissions to execute that command, the function calls the corresponding
766 * command handler which does argument checking and further processing.
768 * In order to cope with a DOS attacks, a timeout is set up
769 * which terminates the function if the connection was not
770 * authenticated when the timeout expires.
772 * \sa alarm(2), rc4(3), crypt.c, crypt.h
774 int handle_connect(int fd
, struct sockaddr_in
*addr
)
776 int ret
, argc
, use_rc4
= 0;
778 unsigned char crypt_buf
[MAXLINE
];
780 struct server_command
*cmd
= NULL
;
781 long unsigned challenge_nr
, chall_response
;
783 char *p
, *command
= NULL
;
786 signal(SIGCHLD
, SIG_IGN
);
787 signal(SIGINT
, SIG_DFL
);
788 signal(SIGTERM
, SIG_DFL
);
789 signal(SIGHUP
, SIG_DFL
);
790 signal(SIGUSR1
, SIG_IGN
);
792 challenge_nr
= random();
793 /* send Welcome message */
794 ret
= send_va_buffer(fd
, "This is para_server, version "
795 PACKAGE_VERSION
".\n" );
798 /* recv auth request line */
799 ret
= recv_buffer(fd
, buf
, sizeof(buf
));
808 if (strncmp(buf
, "auth ", 5))
811 if (numbytes
< 9 || strncmp(buf
, "auth rc4 ", 9))
812 p
= buf
+ 5; /* client version < 0.2.6 */
814 p
= buf
+ 9; /* client version >= 0.2.6 */
817 PARA_DEBUG_LOG("received %s request for user %s\n",
818 use_rc4
? "rc4" : "auth", p
);
823 ret
= para_encrypt_challenge(u
->rsa
, challenge_nr
, crypt_buf
);
827 PARA_DEBUG_LOG("sending %zu byte challenge\n", numbytes
);
828 /* We can't use send_buffer here since buf may contain null bytes */
829 ret
= send_bin_buffer(fd
,(char *) crypt_buf
, numbytes
);
832 /* recv decrypted number */
833 ret
= recv_buffer(fd
, buf
, sizeof(buf
));
840 if (sscanf(buf
, CHALLENGE_RESPONSE_MSG
"%lu", &chall_response
) < 1
841 || chall_response
!= challenge_nr
)
843 /* auth successful, send 'Proceed' message */
844 PARA_INFO_LOG("good auth for %s (%lu)\n", u
->name
, challenge_nr
);
845 sprintf(buf
, "%s", PROCEED_MSG
);
848 ret
= para_encrypt_buffer(u
->rsa
, rc4_buf
, 2 * RC4_KEY_LEN
,
849 (unsigned char *)buf
+ PROCEED_MSG_LEN
+ 1);
852 numbytes
= ret
+ strlen(PROCEED_MSG
) + 1;
854 numbytes
= strlen(buf
);
855 ret
= send_bin_buffer(fd
, buf
, numbytes
);
859 enable_crypt(fd
, rc4_recv
, rc4_send
, NULL
);
860 ret
= read_command(fd
, &command
);
864 cmd
= parse_cmd(command
);
867 /* valid command, check permissions */
868 ret
= check_perms(u
->perms
, cmd
);
871 /* valid command and sufficient perms */
873 argc
= split_args(command
, &argv
, "\n");
877 PARA_NOTICE_LOG("calling com_%s() for %s@%s\n", cmd
->name
, u
->name
,
878 inet_ntoa(addr
->sin_addr
));
879 ret
= cmd
->handler(fd
, argc
, argv
);
885 PARA_NOTICE_LOG("%s\n", PARA_STRERROR(-ret
));
886 if (ret
!= -E_SEND
&& ret
!= -E_RECV
)
887 send_va_buffer(fd
, "%s\n", PARA_STRERROR(-ret
));
893 if (cmd
&& (cmd
->perms
& AFS_WRITE
) && ret
>= 0)
895 mmd
->active_connections
--;