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
--;