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"
29 /** commands including options must be shorter than this */
30 #define MAX_COMMAND_LEN 4096
32 static RC4_KEY rc4_recv_key
;
33 static RC4_KEY rc4_send_key
;
34 static unsigned char rc4_buf
[2 * RC4_KEY_LEN
];
36 extern const char *status_item_list
[NUM_STAT_ITEMS
];
37 extern struct misc_meta_data
*mmd
;
38 extern struct audio_file_selector selectors
[];
39 extern struct sender senders
[];
41 static void dummy(__a_unused
int s
)
44 static void mmd_dup(struct misc_meta_data
*new_mmd
)
52 * compute human readable string containing
53 * vss status for given integer value
55 static char *vss_status_tohuman(unsigned int flags
)
57 if (flags
& VSS_PLAYING
)
58 return para_strdup("playing");
59 else if (flags
& VSS_NEXT
)
60 return para_strdup("stopped");
62 return para_strdup("paused");
66 * return human readable permission string. Never returns NULL.
68 static char *cmd_perms_itohuman(unsigned int perms
)
70 char *msg
= para_malloc(5 * sizeof(char));
72 msg
[0] = perms
& AFS_READ
? 'a' : '-';
73 msg
[1] = perms
& AFS_WRITE
? 'A' : '-';
74 msg
[2] = perms
& VSS_READ
? 'v' : '-';
75 msg
[3] = perms
& VSS_WRITE
? 'V' : '-';
83 static char *vss_get_status_flags(unsigned int flags
)
85 char *msg
= para_malloc(5 * sizeof(char));
87 msg
[0] = (flags
& VSS_PLAYING
)? 'P' : '_';
88 msg
[1] = (flags
& VSS_NOMORE
)? 'O' : '_';
89 msg
[2] = (flags
& VSS_NEXT
)? 'N' : '_';
90 msg
[3] = (flags
& VSS_REPOS
)? 'R' : '_';
96 * compute status bar string. Never returns NULL
98 static char *get_sb_string(struct misc_meta_data
*nmmd
)
101 long long unsigned secs
= 0, rsecs
= 0, percent
= 0;
103 base
= para_basename(nmmd
->filename
);
105 return para_strdup("");
108 if (nmmd
->afi
.chunks_total
) {
109 secs
= (long long) nmmd
->afi
.seconds_total
* nmmd
->chunks_sent
110 / nmmd
->afi
.chunks_total
;
111 rsecs
= (long long) nmmd
->afi
.seconds_total
*
112 (nmmd
->afi
.chunks_total
- nmmd
->chunks_sent
)
113 / nmmd
->afi
.chunks_total
;
114 percent
= 100 * ((nmmd
->chunks_sent
+ 5) / 10)
115 / ((nmmd
->afi
.chunks_total
+ 5) / 10);
117 ret
= make_message("%llu:%02llu [%llu:%02llu] (%llu%%) %s",
118 secs
/ 60, secs
% 60,
119 rsecs
/ 60, rsecs
% 60,
127 static char *get_status(struct misc_meta_data
*nmmd
)
129 char *bar
, *ret
, mtime
[30] = "";
130 char *status
, *flags
; /* vss status info */
131 char *ut
= uptime_str();
132 long offset
= (nmmd
->offset
+ 500) / 1000;
136 if (nmmd
->audio_format
>= 0) {
137 localtime_r(&nmmd
->mtime
, &mtime_tm
);
138 strftime(mtime
, 29, "%a %b %d %Y", &mtime_tm
);
140 /* report real status */
141 status
= vss_status_tohuman(nmmd
->vss_status_flags
);
142 flags
= vss_get_status_flags(nmmd
->vss_status_flags
);
143 bar
= para_basename(nmmd
->filename
);
144 gettimeofday(&now
, NULL
);
146 "%s:%zu\n" "%s:%s\n" "%s:%lu\n" "%s:%u\n"
147 "%s:%s\n" "%s:%s\n" "%s:%s\n" "%s:%s\n"
148 "%s:%li\n" "%s:%s\n" "%s" "%s"
149 "%s:%s\n" "%s:%lu.%lu\n" "%s:%lu.%lu\n",
150 status_item_list
[SI_FILE_SIZE
], nmmd
->size
/ 1024,
151 status_item_list
[SI_MTIME
], mtime
,
152 status_item_list
[SI_LENGTH
], nmmd
->afi
.seconds_total
,
153 status_item_list
[SI_NUM_PLAYED
], nmmd
->num_played
,
155 status_item_list
[SI_STATUS_BAR
], bar
? bar
: "(none)",
156 status_item_list
[SI_STATUS
], status
,
157 status_item_list
[SI_STATUS_FLAGS
], flags
,
158 status_item_list
[SI_SELECTOR
], selectors
[nmmd
->selector_num
].name
,
160 status_item_list
[SI_OFFSET
], offset
,
161 status_item_list
[SI_FORMAT
], audio_format_name(nmmd
->audio_format
),
163 nmmd
->afi
.info_string
,
165 status_item_list
[SI_UPTIME
], ut
,
166 status_item_list
[SI_STREAM_START
],
167 (long unsigned)nmmd
->stream_start
.tv_sec
,
168 (long unsigned)nmmd
->stream_start
.tv_usec
,
169 status_item_list
[SI_CURRENT_TIME
],
170 (long unsigned)now
.tv_sec
,
171 (long unsigned)now
.tv_usec
181 static int check_sender_args(int argc
, char **argv
, struct sender_command_data
*scd
)
184 /* this has to match sender.h */
185 const char *subcmds
[] = {"add", "delete", "allow", "deny", "on", "off", NULL
};
187 scd
->sender_num
= -1;
189 return -E_COMMAND_SYNTAX
;
190 for (i
= 0; senders
[i
].name
; i
++)
191 if (!strcmp(senders
[i
].name
, argv
[1]))
193 PARA_DEBUG_LOG("%d:%s\n", argc
, argv
[1]);
194 if (!senders
[i
].name
)
195 return -E_COMMAND_SYNTAX
;
197 for (i
= 0; subcmds
[i
]; i
++)
198 if (!strcmp(subcmds
[i
], argv
[2]))
201 return -E_COMMAND_SYNTAX
;
204 if (!senders
[scd
->sender_num
].client_cmds
[scd
->cmd_num
]) {
206 return -E_SENDER_CMD
;
209 switch (scd
->cmd_num
) {
213 return -E_COMMAND_SYNTAX
;
217 if (argc
!= 4 && argc
!= 5)
218 return -E_COMMAND_SYNTAX
;
219 if (!inet_aton(argv
[3], &scd
->addr
))
220 return -E_COMMAND_SYNTAX
;
223 scd
->netmask
= atoi(argv
[4]);
224 if (scd
->netmask
< 0 || scd
->netmask
> 32)
225 return -E_COMMAND_SYNTAX
;
230 if (argc
!= 4 && argc
!= 5)
231 return -E_COMMAND_SYNTAX
;
232 if (!inet_aton(argv
[3], &scd
->addr
))
233 return -E_COMMAND_SYNTAX
;
236 scd
->port
= atoi(argv
[4]);
237 if (scd
->port
< 0 || scd
->port
> 65535)
238 return -E_COMMAND_SYNTAX
;
242 return -E_COMMAND_SYNTAX
;
247 int com_sender(int fd
, int argc
, char **argv
)
250 struct sender_command_data scd
;
254 for (i
= 0; senders
[i
].name
; i
++) {
255 char *tmp
= make_message("%s%s\n",
256 msg
? msg
: "", senders
[i
].name
);
260 ret
= send_buffer(fd
, msg
);
264 ret
= check_sender_args(argc
, argv
, &scd
);
267 if (scd
.sender_num
< 0)
269 msg
= senders
[scd
.sender_num
].help();
270 send_buffer(fd
, msg
);
274 for (i
= 0; i
< 10; i
++) {
276 if (mmd
->sender_cmd_data
.cmd_num
>= 0) {
281 mmd
->sender_cmd_data
= scd
;
285 return (i
< 10)? 1 : -E_LOCK
;
289 int com_si(int fd
, int argc
, __a_unused
char **argv
)
293 char *selector_string
= NULL
, *sender_info
= NULL
, *sender_list
= NULL
;
296 return -E_COMMAND_SYNTAX
;
298 for (i
= 0; selectors
[i
].name
; i
++) {
299 selector_string
= para_strcat(selector_string
, selectors
[i
].name
);
300 selector_string
= para_strcat(selector_string
, " ");
302 for (i
= 0; senders
[i
].name
; i
++) {
303 char *info
= senders
[i
].info();
304 sender_info
= para_strcat(sender_info
, info
);
306 sender_list
= para_strcat(sender_list
, senders
[i
].name
);
307 sender_list
= para_strcat(sender_list
, " ");
310 ret
= send_va_buffer(fd
, "up: %s\nplayed: %u\n"
312 "connections (active/accepted/total): %u/%u/%u\n"
313 "current loglevel: %i\n"
314 "supported audio file selectors: %s\n"
315 "supported audio formats: %s\n"
316 "supported senders: %s\n"
320 mmd
->active_connections
,
325 supported_audio_formats(),
331 free(selector_string
);
338 int com_version(int fd
, int argc
, __a_unused
char **argv
)
341 return -E_COMMAND_SYNTAX
;
342 return send_buffer(fd
, VERSION_TEXT("server")
343 "built: " BUILD_DATE
"\n"
344 SYSTEM
", " CC_VERSION
"\n"
349 int com_sc(int fd
, int argc
, char **argv
)
352 int ret
, old
= 0, count
= -1; /* print af change forever */
355 count
= atoi(argv
[1]);
358 if (old
!= mmd
->num_played
) {
359 old
= mmd
->num_played
;
360 name
= para_strdup(mmd
->filename
);
364 ret
= send_va_buffer(fd
, "%s\n", name
);
369 if (argc
> 1 && !--count
)
377 int com_sb(int fd
, int argc
, char **argv
)
380 int ret
, nr
= -1; /* status bar will be printed that many
381 * times. Negative value means: print
388 sb
= get_sb_string(mmd
);
390 ret
= send_va_buffer(fd
, "%s\n", sb
);
404 int com_stat(int fd
, int argc
, char **argv
)
406 int ret
, num
= 0;/* status will be printed that many
407 * times. num <= 0 means: print forever
409 struct misc_meta_data tmp
, *nmmd
= &tmp
;
412 signal(SIGUSR1
, dummy
);
419 s
= get_status(nmmd
);
420 ret
= send_buffer(fd
, s
);
429 return -E_SERVER_CRASH
;
435 static int send_list_of_commands(int fd
, struct server_command
*cmd
,
440 for (i
= 1; cmd
->name
; cmd
++, i
++) {
441 char *perms
= cmd_perms_itohuman(cmd
->perms
);
442 ret
= send_va_buffer(fd
, "%s\t%s\t%s\t%s\n", cmd
->name
,
453 /* always returns string that must be freed by the caller in handler */
454 static struct server_command
*get_cmd_ptr(char *name
, char **handler
)
456 struct server_command
*cmd
;
458 for (cmd
= server_cmds
; cmd
->name
; cmd
++)
459 if (!strcmp(cmd
->name
, name
)) {
461 *handler
= para_strdup("para_server"); /* server commands */
464 /* not found, look for commands supported by the current selector */
467 *handler
= make_message("the %s selector",
468 selectors
[mmd
->selector_num
].name
);
469 cmd
= selectors
[mmd
->selector_num
].cmd_list
;
471 for (; cmd
->name
; cmd
++)
472 if (!strcmp(cmd
->name
, name
))
478 int com_help(int fd
, int argc
, char **argv
)
480 struct server_command
*cmd
;
481 char *perms
, *handler
;
485 /* no argument given, print list of commands */
486 if ((ret
= send_list_of_commands(fd
, server_cmds
, "server")) < 0)
489 handler
= para_strdup(selectors
[mmd
->selector_num
].name
);
490 cmd
= selectors
[mmd
->selector_num
].cmd_list
;
492 ret
= send_list_of_commands(fd
, cmd
, handler
);
496 /* argument given for help */
497 cmd
= get_cmd_ptr(argv
[1], &handler
);
502 perms
= cmd_perms_itohuman(cmd
->perms
);
503 ret
= send_va_buffer(fd
,
522 int com_hup(__a_unused
int fd
, int argc
, __a_unused
char **argv
)
525 return -E_COMMAND_SYNTAX
;
526 kill(getppid(), SIGHUP
);
531 int com_term(__a_unused
int fd
, int argc
, __a_unused
char **argv
)
534 return -E_COMMAND_SYNTAX
;
535 kill(getppid(), SIGTERM
);
539 int com_play(__a_unused
int fd
, int argc
, __a_unused
char **argv
)
542 return -E_COMMAND_SYNTAX
;
544 mmd
->new_vss_status_flags
|= VSS_PLAYING
;
545 mmd
->new_vss_status_flags
&= ~VSS_NOMORE
;
552 int com_stop(__a_unused
int fd
, int argc
, __a_unused
char **argv
)
555 return -E_COMMAND_SYNTAX
;
557 mmd
->new_vss_status_flags
&= ~VSS_PLAYING
;
558 mmd
->new_vss_status_flags
&= ~VSS_REPOS
;
559 mmd
->new_vss_status_flags
|= VSS_NEXT
;
565 int com_pause(__a_unused
int fd
, int argc
, __a_unused
char **argv
)
568 return -E_COMMAND_SYNTAX
;
572 mmd
->new_vss_status_flags
&= ~VSS_PLAYING
;
573 mmd
->new_vss_status_flags
&= ~VSS_NEXT
;
578 int com_chs(int fd
, int argc
, char **argv
)
585 selector
= para_strdup(selectors
[mmd
->selector_num
].name
);
587 ret
= send_va_buffer(fd
, "%s\n", selector
);
591 for (i
= 0; selectors
[i
].name
; i
++) {
592 if (strcmp(selectors
[i
].name
, argv
[1]))
595 mmd
->selector_change
= i
;
600 return -E_BAD_SELECTOR
;
604 int com_next(__a_unused
int fd
, int argc
, __a_unused
char **argv
)
607 return -E_COMMAND_SYNTAX
;
610 mmd
->new_vss_status_flags
|= VSS_NEXT
;
616 int com_nomore(__a_unused
int fd
, int argc
, __a_unused
char **argv
)
619 return -E_COMMAND_SYNTAX
;
621 if (vss_playing() || vss_paused())
622 mmd
->new_vss_status_flags
|= VSS_NOMORE
;
628 int com_ff(__a_unused
int fd
, int argc
, char **argv
)
631 int ret
, backwards
= 0;
636 return -E_COMMAND_SYNTAX
;
637 if (!(ret
= sscanf(argv
[1], "%u%c", &i
, &c
)))
638 return -E_COMMAND_SYNTAX
;
639 if (ret
> 1 && c
== '-')
640 backwards
= 1; /* jmp backwards */
642 ret
= -E_NO_AUDIO_FILE
;
643 if (!mmd
->afi
.chunks_total
|| !mmd
->afi
.seconds_total
)
645 promille
= (1000 * mmd
->current_chunk
) / mmd
->afi
.chunks_total
;
647 promille
-= 1000 * i
/ mmd
->afi
.seconds_total
;
649 promille
+= 1000 * i
/ mmd
->afi
.seconds_total
;
652 if (promille
> 1000) {
653 mmd
->new_vss_status_flags
|= VSS_NEXT
;
656 mmd
->repos_request
= (mmd
->afi
.chunks_total
* promille
) / 1000;
657 mmd
->new_vss_status_flags
|= VSS_REPOS
;
658 mmd
->new_vss_status_flags
&= ~VSS_NEXT
;
667 int com_jmp(__a_unused
int fd
, int argc
, char **argv
)
673 return -E_COMMAND_SYNTAX
;
674 if (sscanf(argv
[1], "%lu", &i
) <= 0)
675 return -E_COMMAND_SYNTAX
;
677 ret
= -E_NO_AUDIO_FILE
;
678 if (!mmd
->afi
.chunks_total
)
682 PARA_INFO_LOG("jumping to %lu%%\n", i
);
683 mmd
->repos_request
= (mmd
->afi
.chunks_total
* i
+ 50)/ 100;
684 PARA_INFO_LOG("sent: %lu, offset before jmp: %lu\n",
685 mmd
->chunks_sent
, mmd
->offset
);
686 mmd
->new_vss_status_flags
|= VSS_REPOS
;
687 mmd
->new_vss_status_flags
&= ~VSS_NEXT
;
696 * check if perms are sufficient to exec a command having perms cmd_perms.
697 * Returns 0 if perms are sufficient, -E_PERM otherwise.
699 static int check_perms(unsigned int perms
, struct server_command
*cmd_ptr
)
701 PARA_DEBUG_LOG("%s", "checking permissions\n");
702 return (cmd_ptr
->perms
& perms
) < cmd_ptr
->perms
? -E_PERM
: 0;
706 * Parse first string from *cmd and lookup in table of valid commands.
707 * On error, NULL is returned.
709 static struct server_command
*parse_cmd(const char *cmdstr
)
714 sscanf(cmdstr
, "%200s%n", buf
, &n
);
718 return get_cmd_ptr(buf
, NULL
);
721 static long int para_rand(long unsigned max
)
723 return (long int) ((max
+ 0.0) * (random() / (RAND_MAX
+ 1.0)));
726 static void init_rc4_keys(void)
730 for (i
= 0; i
< 2 * RC4_KEY_LEN
; i
++)
731 rc4_buf
[i
] = para_rand(256);
732 PARA_DEBUG_LOG("rc4 keys initialized (%u:%u)\n",
733 (unsigned char) rc4_buf
[0],
734 (unsigned char) rc4_buf
[RC4_KEY_LEN
]);
735 RC4_set_key(&rc4_recv_key
, RC4_KEY_LEN
, rc4_buf
);
736 RC4_set_key(&rc4_send_key
, RC4_KEY_LEN
, rc4_buf
+ RC4_KEY_LEN
);
739 static void rc4_recv(unsigned long len
, const unsigned char *indata
,
740 unsigned char *outdata
, __a_unused
void *private_data
)
742 RC4(&rc4_recv_key
, len
, indata
, outdata
);
745 static void rc4_send(unsigned long len
, const unsigned char *indata
,
746 unsigned char *outdata
, __a_unused
void *private_data
)
748 RC4(&rc4_send_key
, len
, indata
, outdata
);
751 static int read_command(int fd
, char **result
)
755 char *command
= NULL
;
761 ret
= recv_buffer(fd
, buf
, sizeof(buf
));
767 ret
= -E_COMMAND_SYNTAX
;
768 if (command
&& numbytes
+ strlen(command
) > MAX_COMMAND_LEN
) /* DOS */
770 command
= para_strcat(command
, buf
);
771 p
= strstr(command
, EOC_MSG
);
777 ret
= command
? 1 : -E_COMMAND_SYNTAX
;
788 * perform user authentication and execute a command
790 * \param fd the file descriptor to send output to
791 * \param addr socket address info of peer
793 * \return EXIT_SUCCESS or EXIT_FAILURE
795 * Whenever para_server accepts an incoming tcp connection on
796 * the port it listens on, it forks and the resulting child
797 * calls this function.
799 * An RSA-based challenge/response is used to authenticate
800 * the peer. It that authentication succeeds, a random RC4
801 * session key is generated and sent back to the peer,
802 * encrypted with its RSA public key. From this point on,
803 * all transfers are crypted with this session key.
805 * Next it is checked if the peer supplied a valid server
806 * command or a command for the audio file selector currently
807 * in use. If yes, and if the user has sufficient
808 * permissions to execute that command, the function calls
809 * the corresponding command handler which does argument
810 * checking and further processing.
812 * In order to cope with a DOS attacks, a timeout is set up
813 * which terminates the function if the connection was not
814 * authenticated when the timeout expires.
816 * \sa alarm(2), rc4(3), crypt.c, crypt.h
818 int handle_connect(int fd
, struct sockaddr_in
*addr
)
820 int ret
, argc
, use_rc4
= 0;
822 unsigned char crypt_buf
[MAXLINE
];
824 struct server_command
*cmd
= NULL
;
825 long unsigned challenge_nr
, chall_response
;
827 char *p
, *command
= NULL
;
830 signal(SIGCHLD
, SIG_IGN
);
831 signal(SIGINT
, SIG_DFL
);
832 signal(SIGTERM
, SIG_DFL
);
833 signal(SIGHUP
, SIG_DFL
);
834 signal(SIGUSR1
, SIG_IGN
);
836 challenge_nr
= random();
837 /* send Welcome message */
838 ret
= send_va_buffer(fd
, "This is para_server, version "
839 PACKAGE_VERSION
".\n" );
842 /* recv auth request line */
843 ret
= recv_buffer(fd
, buf
, sizeof(buf
));
852 if (strncmp(buf
, "auth ", 5))
855 if (numbytes
< 9 || strncmp(buf
, "auth rc4 ", 9))
856 p
= buf
+ 5; /* client version < 0.2.6 */
858 p
= buf
+ 9; /* client version >= 0.2.6 */
861 PARA_DEBUG_LOG("received %s request for user %s\n",
862 use_rc4
? "rc4" : "auth", p
);
867 ret
= para_encrypt_challenge(u
->rsa
, challenge_nr
, crypt_buf
);
871 PARA_DEBUG_LOG("sending %zu byte challenge\n", numbytes
);
872 /* We can't use send_buffer here since buf may contain null bytes */
873 ret
= send_bin_buffer(fd
,(char *) crypt_buf
, numbytes
);
876 /* recv decrypted number */
877 ret
= recv_buffer(fd
, buf
, sizeof(buf
));
884 if (sscanf(buf
, CHALLENGE_RESPONSE_MSG
"%lu", &chall_response
) < 1
885 || chall_response
!= challenge_nr
)
887 /* auth successful, send 'Proceed' message */
888 PARA_INFO_LOG("good auth for %s (%lu)\n", u
->name
, challenge_nr
);
889 sprintf(buf
, "%s", PROCEED_MSG
);
892 ret
= para_encrypt_buffer(u
->rsa
, rc4_buf
, 2 * RC4_KEY_LEN
,
893 (unsigned char *)buf
+ PROCEED_MSG_LEN
+ 1);
896 numbytes
= ret
+ strlen(PROCEED_MSG
) + 1;
898 numbytes
= strlen(buf
);
899 ret
= send_bin_buffer(fd
, buf
, numbytes
);
903 enable_crypt(fd
, rc4_recv
, rc4_send
, NULL
);
904 ret
= read_command(fd
, &command
);
908 cmd
= parse_cmd(command
);
911 /* valid command, check permissions */
912 ret
= check_perms(u
->perms
, cmd
);
915 /* valid command and sufficient perms */
917 argc
= split_args(command
, &argv
, "\n");
921 PARA_NOTICE_LOG("calling com_%s() for %s@%s\n", cmd
->name
, u
->name
,
922 inet_ntoa(addr
->sin_addr
));
923 ret
= cmd
->handler(fd
, argc
, argv
);
929 PARA_NOTICE_LOG("%s\n", PARA_STRERROR(-ret
));
930 if (ret
!= -E_SEND
&& ret
!= -E_RECV
)
931 send_va_buffer(fd
, "%s\n", PARA_STRERROR(-ret
));
937 if (cmd
&& (cmd
->perms
& AFS_WRITE
) && ret
>= 0)
939 mmd
->active_connections
--;