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>
26 #include "user_list.h"
27 #include "server_command_list.h"
28 #include "afs_command_list.h"
30 /** commands including options must be shorter than this */
31 #define MAX_COMMAND_LEN 32768
33 static RC4_KEY rc4_recv_key
;
34 static RC4_KEY rc4_send_key
;
35 static unsigned char rc4_buf
[2 * RC4_KEY_LEN
];
37 extern const char *status_item_list
[NUM_STAT_ITEMS
];
38 extern struct misc_meta_data
*mmd
;
39 extern struct audio_file_selector selectors
[];
40 extern struct sender senders
[];
42 static void dummy(__a_unused
int s
)
45 static void mmd_dup(struct misc_meta_data
*new_mmd
)
53 * compute human readable string containing
54 * vss status for given integer value
56 static char *vss_status_tohuman(unsigned int flags
)
58 if (flags
& VSS_PLAYING
)
59 return para_strdup("playing");
60 else if (flags
& VSS_NEXT
)
61 return para_strdup("stopped");
63 return para_strdup("paused");
67 * return human readable permission string. Never returns NULL.
69 static char *cmd_perms_itohuman(unsigned int perms
)
71 char *msg
= para_malloc(5 * sizeof(char));
73 msg
[0] = perms
& AFS_READ
? 'a' : '-';
74 msg
[1] = perms
& AFS_WRITE
? 'A' : '-';
75 msg
[2] = perms
& VSS_READ
? 'v' : '-';
76 msg
[3] = perms
& VSS_WRITE
? 'V' : '-';
84 static char *vss_get_status_flags(unsigned int flags
)
86 char *msg
= para_malloc(5 * sizeof(char));
88 msg
[0] = (flags
& VSS_PLAYING
)? 'P' : '_';
89 msg
[1] = (flags
& VSS_NOMORE
)? 'O' : '_';
90 msg
[2] = (flags
& VSS_NEXT
)? 'N' : '_';
91 msg
[3] = (flags
& VSS_REPOS
)? 'R' : '_';
97 * compute status bar string. Never returns NULL
99 static char *get_sb_string(struct misc_meta_data
*nmmd
)
102 long long unsigned secs
= 0, rsecs
= 0, percent
= 0;
104 base
= para_basename(nmmd
->filename
);
106 return para_strdup("");
109 if (nmmd
->afi
.chunks_total
) {
110 secs
= (long long) nmmd
->afi
.seconds_total
* nmmd
->chunks_sent
111 / nmmd
->afi
.chunks_total
;
112 rsecs
= (long long) nmmd
->afi
.seconds_total
*
113 (nmmd
->afi
.chunks_total
- nmmd
->chunks_sent
)
114 / nmmd
->afi
.chunks_total
;
115 percent
= 100 * ((nmmd
->chunks_sent
+ 5) / 10)
116 / ((nmmd
->afi
.chunks_total
+ 5) / 10);
118 ret
= make_message("%llu:%02llu [%llu:%02llu] (%llu%%) %s",
119 secs
/ 60, secs
% 60,
120 rsecs
/ 60, rsecs
% 60,
128 static char *get_status(struct misc_meta_data
*nmmd
)
130 char *bar
, *ret
, mtime
[30] = "";
131 char *status
, *flags
; /* vss status info */
132 char *ut
= uptime_str();
133 long offset
= (nmmd
->offset
+ 500) / 1000;
137 if (nmmd
->audio_format
>= 0) {
138 localtime_r(&nmmd
->mtime
, &mtime_tm
);
139 strftime(mtime
, 29, "%a %b %d %Y", &mtime_tm
);
141 /* report real status */
142 status
= vss_status_tohuman(nmmd
->vss_status_flags
);
143 flags
= vss_get_status_flags(nmmd
->vss_status_flags
);
144 bar
= para_basename(nmmd
->filename
);
145 gettimeofday(&now
, NULL
);
147 "%s:%zu\n" "%s:%s\n" "%s:%lu\n" "%s:%u\n"
148 "%s:%s\n" "%s:%s\n" "%s:%s\n" "%s:%s\n"
149 "%s:%li\n" "%s:%s\n" "%s" "%s"
150 "%s:%s\n" "%s:%lu.%lu\n" "%s:%lu.%lu\n",
151 status_item_list
[SI_FILE_SIZE
], nmmd
->size
/ 1024,
152 status_item_list
[SI_MTIME
], mtime
,
153 status_item_list
[SI_LENGTH
], nmmd
->afi
.seconds_total
,
154 status_item_list
[SI_NUM_PLAYED
], nmmd
->num_played
,
156 status_item_list
[SI_STATUS_BAR
], bar
? bar
: "(none)",
157 status_item_list
[SI_STATUS
], status
,
158 status_item_list
[SI_STATUS_FLAGS
], flags
,
159 status_item_list
[SI_SELECTOR
], selectors
[nmmd
->selector_num
].name
,
161 status_item_list
[SI_OFFSET
], offset
,
162 status_item_list
[SI_FORMAT
], audio_format_name(nmmd
->audio_format
),
164 nmmd
->afi
.info_string
,
166 status_item_list
[SI_UPTIME
], ut
,
167 status_item_list
[SI_STREAM_START
],
168 (long unsigned)nmmd
->stream_start
.tv_sec
,
169 (long unsigned)nmmd
->stream_start
.tv_usec
,
170 status_item_list
[SI_CURRENT_TIME
],
171 (long unsigned)now
.tv_sec
,
172 (long unsigned)now
.tv_usec
182 static int check_sender_args(int argc
, char * const * argv
, struct sender_command_data
*scd
)
185 /* this has to match sender.h */
186 const char *subcmds
[] = {"add", "delete", "allow", "deny", "on", "off", NULL
};
188 scd
->sender_num
= -1;
190 return -E_COMMAND_SYNTAX
;
191 for (i
= 0; senders
[i
].name
; i
++)
192 if (!strcmp(senders
[i
].name
, argv
[1]))
194 PARA_DEBUG_LOG("%d:%s\n", argc
, argv
[1]);
195 if (!senders
[i
].name
)
196 return -E_COMMAND_SYNTAX
;
198 for (i
= 0; subcmds
[i
]; i
++)
199 if (!strcmp(subcmds
[i
], argv
[2]))
202 return -E_COMMAND_SYNTAX
;
205 if (!senders
[scd
->sender_num
].client_cmds
[scd
->cmd_num
]) {
207 return -E_SENDER_CMD
;
210 switch (scd
->cmd_num
) {
214 return -E_COMMAND_SYNTAX
;
218 if (argc
!= 4 && argc
!= 5)
219 return -E_COMMAND_SYNTAX
;
220 if (!inet_aton(argv
[3], &scd
->addr
))
221 return -E_COMMAND_SYNTAX
;
224 scd
->netmask
= atoi(argv
[4]);
225 if (scd
->netmask
< 0 || scd
->netmask
> 32)
226 return -E_COMMAND_SYNTAX
;
231 if (argc
!= 4 && argc
!= 5)
232 return -E_COMMAND_SYNTAX
;
233 if (!inet_aton(argv
[3], &scd
->addr
))
234 return -E_COMMAND_SYNTAX
;
237 scd
->port
= atoi(argv
[4]);
238 if (scd
->port
< 0 || scd
->port
> 65535)
239 return -E_COMMAND_SYNTAX
;
243 return -E_COMMAND_SYNTAX
;
248 int com_sender(int fd
, int argc
, char * const * argv
)
251 struct sender_command_data scd
;
255 for (i
= 0; senders
[i
].name
; i
++) {
256 char *tmp
= make_message("%s%s\n",
257 msg
? msg
: "", senders
[i
].name
);
261 ret
= send_buffer(fd
, msg
);
265 ret
= check_sender_args(argc
, argv
, &scd
);
268 if (scd
.sender_num
< 0)
270 msg
= senders
[scd
.sender_num
].help();
271 send_buffer(fd
, msg
);
275 for (i
= 0; i
< 10; i
++) {
277 if (mmd
->sender_cmd_data
.cmd_num
>= 0) {
282 mmd
->sender_cmd_data
= scd
;
286 return (i
< 10)? 1 : -E_LOCK
;
290 int com_si(int fd
, int argc
, __a_unused
char * const * argv
)
294 char *selector_string
= NULL
, *sender_info
= NULL
, *sender_list
= NULL
;
297 return -E_COMMAND_SYNTAX
;
299 for (i
= 0; selectors
[i
].name
; i
++) {
300 selector_string
= para_strcat(selector_string
, selectors
[i
].name
);
301 selector_string
= para_strcat(selector_string
, " ");
303 for (i
= 0; senders
[i
].name
; i
++) {
304 char *info
= senders
[i
].info();
305 sender_info
= para_strcat(sender_info
, info
);
307 sender_list
= para_strcat(sender_list
, senders
[i
].name
);
308 sender_list
= para_strcat(sender_list
, " ");
311 ret
= send_va_buffer(fd
, "up: %s\nplayed: %u\n"
313 "connections (active/accepted/total): %u/%u/%u\n"
314 "current loglevel: %i\n"
315 "supported audio file selectors: %s\n"
316 "supported audio formats: %s\n"
317 "supported senders: %s\n"
321 mmd
->active_connections
,
326 supported_audio_formats(),
332 free(selector_string
);
339 int com_version(int fd
, int argc
, __a_unused
char * const * argv
)
342 return -E_COMMAND_SYNTAX
;
343 return send_buffer(fd
, VERSION_TEXT("server")
344 "built: " BUILD_DATE
"\n"
345 SYSTEM
", " CC_VERSION
"\n"
350 int com_sc(int fd
, int argc
, char * const * argv
)
353 int ret
, old
= 0, count
= -1; /* print af change forever */
356 count
= atoi(argv
[1]);
359 if (old
!= mmd
->num_played
) {
360 old
= mmd
->num_played
;
361 name
= para_strdup(mmd
->filename
);
365 ret
= send_va_buffer(fd
, "%s\n", name
);
370 if (argc
> 1 && !--count
)
378 int com_sb(int fd
, int argc
, char * const * argv
)
381 int ret
, nr
= -1; /* status bar will be printed that many
382 * times. Negative value means: print
389 sb
= get_sb_string(mmd
);
391 ret
= send_va_buffer(fd
, "%s\n", sb
);
405 int com_stat(int fd
, int argc
, char * const * argv
)
407 int ret
, num
= 0;/* status will be printed that many
408 * times. num <= 0 means: print forever
410 struct misc_meta_data tmp
, *nmmd
= &tmp
;
413 signal(SIGUSR1
, dummy
);
420 s
= get_status(nmmd
);
421 ret
= send_buffer(fd
, s
);
430 return -E_SERVER_CRASH
;
436 static int send_list_of_commands(int fd
, struct server_command
*cmd
,
441 for (i
= 1; cmd
->name
; cmd
++, i
++) {
442 char *perms
= cmd_perms_itohuman(cmd
->perms
);
443 ret
= send_va_buffer(fd
, "%s\t%s\t%s\t%s\n", cmd
->name
,
454 /* always returns string that must be freed by the caller in handler */
455 static struct server_command
*get_cmd_ptr(const char *name
, char **handler
)
457 struct server_command
*cmd
;
459 for (cmd
= server_cmds
; cmd
->name
; cmd
++)
460 if (!strcmp(cmd
->name
, name
)) {
462 *handler
= para_strdup("para_server"); /* server commands */
465 /* not found, look for commands supported by the current selector */
468 *handler
= make_message("the %s selector",
469 selectors
[mmd
->selector_num
].name
);
470 cmd
= selectors
[mmd
->selector_num
].cmd_list
;
472 for (; cmd
->name
; cmd
++)
473 if (!strcmp(cmd
->name
, name
))
475 /* not found, look for commands supported by afs */
476 for (cmd
= afs_cmds
; cmd
; cmd
++)
477 if (!strcmp(cmd
->name
, name
))
483 int com_help(int fd
, int argc
, char * const * argv
)
485 struct server_command
*cmd
;
486 char *perms
, *handler
;
490 /* no argument given, print list of commands */
491 if ((ret
= send_list_of_commands(fd
, server_cmds
, "server")) < 0)
494 handler
= para_strdup(selectors
[mmd
->selector_num
].name
);
495 cmd
= selectors
[mmd
->selector_num
].cmd_list
;
497 ret
= send_list_of_commands(fd
, cmd
, handler
);
502 ret
= send_list_of_commands(fd
, cmd
, "afs");
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 * const * argv
)
533 return -E_COMMAND_SYNTAX
;
534 kill(getppid(), SIGHUP
);
539 int com_term(__a_unused
int fd
, int argc
, __a_unused
char * const * argv
)
542 return -E_COMMAND_SYNTAX
;
543 kill(getppid(), SIGTERM
);
547 int com_play(__a_unused
int fd
, int argc
, __a_unused
char * const * 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 * const * 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 * const * 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 * const * 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 * const * 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 * const * 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 * const * 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 * const * 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 %zu 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
--;