2 * Copyright (C) 1997 Andre Noll <maan@tuebingen.mpg.de>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file command.c Client authentication and server commands. */
9 #include <netinet/in.h>
10 #include <sys/socket.h>
13 #include <sys/types.h>
15 #include <arpa/inet.h>
24 #include "server.cmdline.h"
37 #include "user_list.h"
38 #include "server.command_list.h"
39 #include "afs.command_list.h"
43 typedef int server_command_handler_t(struct command_context
*);
44 static server_command_handler_t SERVER_COMMAND_HANDLERS
;
45 server_command_handler_t AFS_COMMAND_HANDLERS
;
47 /* Defines one command of para_server. */
48 struct server_command
{
49 /* The name of the command. */
51 /* Pointer to the function that handles the command. */
52 server_command_handler_t
*handler
;
53 /* The privileges a user must have to execute this command. */
55 /* One-line description of the command. */
56 const char *description
;
57 /* Summary of the command line options. */
59 /* The long help text. */
63 static struct server_command afs_cmds
[] = {DEFINE_AFS_CMD_ARRAY
};
64 static struct server_command server_cmds
[] = {DEFINE_SERVER_CMD_ARRAY
};
66 /** Commands including options must be shorter than this. */
67 #define MAX_COMMAND_LEN 32768
70 extern struct misc_meta_data
*mmd
;
71 extern struct sender senders
[];
72 int send_afs_status(struct command_context
*cc
, int parser_friendly
);
74 static void dummy(__a_unused
int s
)
78 static void mmd_dup(struct misc_meta_data
*new_mmd
)
80 mutex_lock(mmd_mutex
);
82 mutex_unlock(mmd_mutex
);
86 * Compute human readable string containing vss status for given integer value.
88 * We don't want to use vss_playing() and friends here because we take a
89 * snapshot of the mmd struct and use the copy for computing the state of the
90 * vss. If the real data were used, we would take the mmd lock for a rather
91 * long time or risk to get an inconsistent view.
93 static char *vss_status_tohuman(unsigned int flags
)
95 if (flags
& VSS_PLAYING
)
96 return para_strdup("playing");
98 return para_strdup("stopped");
99 return para_strdup("paused");
103 * return human readable permission string. Never returns NULL.
105 static char *cmd_perms_itohuman(unsigned int perms
)
107 char *msg
= para_malloc(5 * sizeof(char));
109 msg
[0] = perms
& AFS_READ
? 'a' : '-';
110 msg
[1] = perms
& AFS_WRITE
? 'A' : '-';
111 msg
[2] = perms
& VSS_READ
? 'v' : '-';
112 msg
[3] = perms
& VSS_WRITE
? 'V' : '-';
118 * Never returns NULL.
120 static char *vss_get_status_flags(unsigned int flags
)
122 char *msg
= para_malloc(5 * sizeof(char));
124 msg
[0] = (flags
& VSS_PLAYING
)? 'P' : '_';
125 msg
[1] = (flags
& VSS_NOMORE
)? 'O' : '_';
126 msg
[2] = (flags
& VSS_NEXT
)? 'N' : '_';
127 msg
[3] = (flags
& VSS_REPOS
)? 'R' : '_';
132 static unsigned get_status(struct misc_meta_data
*nmmd
, int parser_friendly
,
135 char *status
, *flags
; /* vss status info */
136 /* nobody updates our version of "now" */
137 long offset
= (nmmd
->offset
+ 500) / 1000;
138 struct timeval current_time
;
139 struct para_buffer b
= {.flags
= parser_friendly
? PBF_SIZE_PREFIX
: 0};
141 /* report real status */
142 status
= vss_status_tohuman(nmmd
->vss_status_flags
);
143 flags
= vss_get_status_flags(nmmd
->vss_status_flags
);
144 clock_get_realtime(¤t_time
);
146 * The calls to WRITE_STATUS_ITEM() below never fail because
147 * b->max_size is zero (unlimited), see para_printf(). However, clang
148 * is not smart enough to prove this and complains nevertheless.
149 * Casting the return value to void silences clang.
151 (void)WRITE_STATUS_ITEM(&b
, SI_STATUS
, "%s\n", status
);
152 (void)WRITE_STATUS_ITEM(&b
, SI_STATUS_FLAGS
, "%s\n", flags
);
153 (void)WRITE_STATUS_ITEM(&b
, SI_OFFSET
, "%li\n", offset
);
154 (void)WRITE_STATUS_ITEM(&b
, SI_AFS_MODE
, "%s\n", mmd
->afs_mode_string
);
155 (void)WRITE_STATUS_ITEM(&b
, SI_STREAM_START
, "%lu.%lu\n",
156 (long unsigned)nmmd
->stream_start
.tv_sec
,
157 (long unsigned)nmmd
->stream_start
.tv_usec
);
158 (void)WRITE_STATUS_ITEM(&b
, SI_CURRENT_TIME
, "%lu.%lu\n",
159 (long unsigned)current_time
.tv_sec
,
160 (long unsigned)current_time
.tv_usec
);
167 static int check_sender_args(int argc
, char * const * argv
, struct sender_command_data
*scd
)
170 /* this has to match sender.h */
171 const char *subcmds
[] = {"add", "delete", "allow", "deny", "on", "off", NULL
};
173 scd
->sender_num
= -1;
175 return -E_COMMAND_SYNTAX
;
176 for (i
= 0; senders
[i
].name
; i
++)
177 if (!strcmp(senders
[i
].name
, argv
[1]))
179 PARA_DEBUG_LOG("%d:%s\n", argc
, argv
[1]);
180 if (!senders
[i
].name
)
181 return -E_COMMAND_SYNTAX
;
183 for (i
= 0; subcmds
[i
]; i
++)
184 if (!strcmp(subcmds
[i
], argv
[2]))
187 return -E_COMMAND_SYNTAX
;
189 if (!senders
[scd
->sender_num
].client_cmds
[scd
->cmd_num
])
190 return -E_SENDER_CMD
;
191 switch (scd
->cmd_num
) {
195 return -E_COMMAND_SYNTAX
;
199 if (argc
!= 4 || parse_cidr(argv
[3], scd
->host
,
200 sizeof(scd
->host
), &scd
->netmask
) == NULL
)
201 return -E_COMMAND_SYNTAX
;
206 return -E_COMMAND_SYNTAX
;
207 return parse_fec_url(argv
[3], scd
);
209 return -E_COMMAND_SYNTAX
;
215 * Send a sideband packet through a blocking file descriptor.
217 * \param scc fd and crypto keys.
218 * \param buf The buffer to send.
219 * \param numbytes The size of \a buf.
220 * \param band The sideband designator of this packet.
221 * \param dont_free If true, never deallocate \a buf.
223 * The nonblock flag must be disabled for the file descriptor given by \a scc.
225 * Stream cipher encryption is automatically activated if necessary via the
226 * sideband transformation, depending on the value of \a band.
230 * \sa \ref send_sb_va().
232 int send_sb(struct stream_cipher_context
*scc
, void *buf
, size_t numbytes
,
233 int band
, bool dont_free
)
236 struct sb_context
*sbc
;
238 sb_transformation trafo
= band
< SBD_PROCEED
? NULL
: sc_trafo
;
239 struct sb_buffer sbb
= SBB_INIT(band
, buf
, numbytes
);
241 sbc
= sb_new_send(&sbb
, dont_free
, trafo
, scc
->send
);
243 ret
= sb_get_send_buffers(sbc
, iov
);
244 ret
= xwritev(scc
->fd
, iov
, ret
);
247 } while (sb_sent(sbc
, ret
) == false);
255 * Create a variable sized buffer and send it as a sideband packet.
257 * \param scc Passed to \ref send_sb.
258 * \param band See \ref send_sb.
259 * \param fmt The format string.
261 * \return The return value of the underlying call to \ref send_sb.
263 __printf_3_4
int send_sb_va(struct stream_cipher_context
*scc
, int band
,
264 const char *fmt
, ...)
271 ret
= xvasprintf(&msg
, fmt
, ap
);
273 return send_sb(scc
, msg
, ret
, band
, false);
277 * Send an error message to a client.
279 * \param cc Client info.
280 * \param err The (positive) error code.
282 * \return The return value of the underlying call to send_sb_va().
284 int send_strerror(struct command_context
*cc
, int err
)
286 return send_sb_va(&cc
->scc
, SBD_ERROR_LOG
, "%s\n", para_strerror(err
));
290 * Send a sideband packet through a blocking file descriptor.
292 * \param scc fd and crypto keys.
293 * \param expected_band The expected band designator.
294 * \param max_size Passed to \ref sb_new_recv().
295 * \param result Body of the sideband packet is returned here.
297 * If \a expected_band is not \p SBD_ANY, the band designator of the received
298 * sideband packet is compared to \a expected_band and a mismatch is considered
303 int recv_sb(struct stream_cipher_context
*scc
,
304 enum sb_designator expected_band
,
305 size_t max_size
, struct iovec
*result
)
308 struct sb_context
*sbc
;
310 struct sb_buffer sbb
;
311 sb_transformation trafo
;
313 trafo
= expected_band
!= SBD_ANY
&& expected_band
< SBD_PROCEED
?
315 sbc
= sb_new_recv(max_size
, trafo
, scc
->recv
);
317 sb_get_recv_buffer(sbc
, &iov
);
318 ret
= recv_bin_buffer(scc
->fd
, iov
.iov_base
, iov
.iov_len
);
323 ret
= sb_received(sbc
, ret
, &sbb
);
330 if (expected_band
!= SBD_ANY
&& sbb
.band
!= expected_band
)
339 static int com_sender(struct command_context
*cc
)
343 struct sender_command_data scd
;
346 for (i
= 0; senders
[i
].name
; i
++) {
348 ret
= xasprintf(&tmp
, "%s%s\n", msg
? msg
: "",
353 return send_sb(&cc
->scc
, msg
, ret
, SBD_OUTPUT
, false);
355 ret
= check_sender_args(cc
->argc
, cc
->argv
, &scd
);
357 if (scd
.sender_num
< 0)
359 if (strcmp(cc
->argv
[2], "status") == 0)
360 msg
= senders
[scd
.sender_num
].status();
362 msg
= senders
[scd
.sender_num
].help();
363 return send_sb(&cc
->scc
, msg
, strlen(msg
), SBD_OUTPUT
, false);
366 switch (scd
.cmd_num
) {
369 assert(senders
[scd
.sender_num
].resolve_target
);
370 ret
= senders
[scd
.sender_num
].resolve_target(cc
->argv
[3], &scd
);
375 for (i
= 0; i
< 10; i
++) {
376 mutex_lock(mmd_mutex
);
377 if (mmd
->sender_cmd_data
.cmd_num
>= 0) {
378 /* another sender command is active, retry in 100ms */
379 struct timespec ts
= {.tv_nsec
= 100 * 1000 * 1000};
380 mutex_unlock(mmd_mutex
);
381 nanosleep(&ts
, NULL
);
384 mmd
->sender_cmd_data
= scd
;
385 mutex_unlock(mmd_mutex
);
388 return (i
< 10)? 1 : -E_LOCK
;
392 static int com_si(struct command_context
*cc
)
398 return -E_COMMAND_SYNTAX
;
399 mutex_lock(mmd_mutex
);
400 ut
= daemon_get_uptime_str(now
);
401 ret
= xasprintf(&msg
,
402 "up: %s\nplayed: %u\n"
405 "connections (active/accepted/total): %u/%u/%u\n"
406 "current loglevel: %s\n"
407 "supported audio formats: %s\n",
411 mmd
->active_connections
,
415 AUDIO_FORMAT_HANDLERS
417 mutex_unlock(mmd_mutex
);
419 return send_sb(&cc
->scc
, msg
, ret
, SBD_OUTPUT
, false);
423 static int com_version(struct command_context
*cc
)
429 return -E_COMMAND_SYNTAX
;
430 len
= xasprintf(&msg
, "%s", version_text("server"));
431 return send_sb(&cc
->scc
, msg
, len
, SBD_OUTPUT
, false);
434 /** These status items are cleared if no audio file is currently open. */
435 #define EMPTY_STATUS_ITEMS \
440 ITEM(ATTRIBUTES_BITMAP) \
441 ITEM(ATTRIBUTES_TXT) \
452 ITEM(SECONDS_TOTAL) \
465 ITEM(AMPLIFICATION) \
468 * Write a list of audio-file related status items with empty values.
470 * This is used by vss when currently no audio file is open.
472 static unsigned empty_status_items(int parser_friendly
, char **result
)
478 len
= xasprintf(&esi
,
479 #define ITEM(x) "0004 %02x:\n"
482 #define ITEM(x) , SI_ ## x
487 len
= xasprintf(&esi
,
488 #define ITEM(x) "%s:\n"
491 #define ITEM(x) ,status_item_list[SI_ ## x]
498 #undef EMPTY_STATUS_ITEMS
501 static int com_stat(struct command_context
*cc
)
504 struct misc_meta_data tmp
, *nmmd
= &tmp
;
507 int parser_friendly
= 0;
509 para_sigaction(SIGUSR1
, dummy
);
511 for (i
= 1; i
< cc
->argc
; i
++) {
512 const char *arg
= cc
->argv
[i
];
515 if (!strcmp(arg
, "--")) {
519 if (!strncmp(arg
, "-n=", 3)) {
520 ret
= para_atoi32(arg
+ 3, &num
);
525 if (!strcmp(arg
, "-p")) {
529 return -E_COMMAND_SYNTAX
;
532 return -E_COMMAND_SYNTAX
;
535 ret
= get_status(nmmd
, parser_friendly
, &s
);
536 ret
= send_sb(&cc
->scc
, s
, ret
, SBD_OUTPUT
, false);
539 if (nmmd
->vss_status_flags
& VSS_NEXT
) {
541 ret
= empty_status_items(parser_friendly
, &esi
);
542 ret
= send_sb(&cc
->scc
, esi
, ret
, SBD_OUTPUT
, false);
546 send_afs_status(cc
, parser_friendly
);
548 if (num
> 0 && !--num
)
551 ret
= -E_SERVER_CRASH
;
559 static int send_list_of_commands(struct command_context
*cc
, struct server_command
*cmd
,
564 for (; cmd
->name
; cmd
++) {
565 char *tmp
, *perms
= cmd_perms_itohuman(cmd
->perms
);
566 tmp
= make_message("%s\t%s\t%s\t%s\n", cmd
->name
, handler
,
567 perms
, cmd
->description
);
569 msg
= para_strcat(msg
, tmp
);
573 return send_sb(&cc
->scc
, msg
, strlen(msg
), SBD_OUTPUT
, false);
576 /* returns string that must be freed by the caller */
577 static struct server_command
*get_cmd_ptr(const char *name
, char **handler
)
579 struct server_command
*cmd
;
581 for (cmd
= server_cmds
; cmd
->name
; cmd
++)
582 if (!strcmp(cmd
->name
, name
)) {
584 *handler
= para_strdup("server"); /* server commands */
587 /* not found, look for commands supported by afs */
588 for (cmd
= afs_cmds
; cmd
->name
; cmd
++)
589 if (!strcmp(cmd
->name
, name
)) {
591 *handler
= para_strdup("afs");
598 static int com_help(struct command_context
*cc
)
600 struct server_command
*cmd
;
601 char *perms
, *handler
, *buf
;
605 /* no argument given, print list of commands */
606 if ((ret
= send_list_of_commands(cc
, server_cmds
, "server")) < 0)
608 return send_list_of_commands(cc
, afs_cmds
, "afs");
610 /* argument given for help */
611 cmd
= get_cmd_ptr(cc
->argv
[1], &handler
);
614 perms
= cmd_perms_itohuman(cmd
->perms
);
615 ret
= xasprintf(&buf
, "%s - %s\n\n"
629 return send_sb(&cc
->scc
, buf
, ret
, SBD_OUTPUT
, false);
633 static int com_hup(struct command_context
*cc
)
636 return -E_COMMAND_SYNTAX
;
637 kill(getppid(), SIGHUP
);
642 static int com_term(struct command_context
*cc
)
645 return -E_COMMAND_SYNTAX
;
646 kill(getppid(), SIGTERM
);
650 static int com_play(struct command_context
*cc
)
653 return -E_COMMAND_SYNTAX
;
654 mutex_lock(mmd_mutex
);
655 mmd
->new_vss_status_flags
|= VSS_PLAYING
;
656 mmd
->new_vss_status_flags
&= ~VSS_NOMORE
;
657 mutex_unlock(mmd_mutex
);
662 static int com_stop(struct command_context
*cc
)
665 return -E_COMMAND_SYNTAX
;
666 mutex_lock(mmd_mutex
);
667 mmd
->new_vss_status_flags
&= ~VSS_PLAYING
;
668 mmd
->new_vss_status_flags
&= ~VSS_REPOS
;
669 mmd
->new_vss_status_flags
|= VSS_NEXT
;
670 mutex_unlock(mmd_mutex
);
675 static int com_pause(struct command_context
*cc
)
678 return -E_COMMAND_SYNTAX
;
679 mutex_lock(mmd_mutex
);
680 if (!vss_paused() && !vss_stopped()) {
682 mmd
->new_vss_status_flags
&= ~VSS_PLAYING
;
683 mmd
->new_vss_status_flags
&= ~VSS_NEXT
;
685 mutex_unlock(mmd_mutex
);
690 static int com_next(struct command_context
*cc
)
693 return -E_COMMAND_SYNTAX
;
694 mutex_lock(mmd_mutex
);
696 mmd
->new_vss_status_flags
|= VSS_NEXT
;
697 mutex_unlock(mmd_mutex
);
702 static int com_nomore(struct command_context
*cc
)
705 return -E_COMMAND_SYNTAX
;
706 mutex_lock(mmd_mutex
);
707 if (vss_playing() || vss_paused())
708 mmd
->new_vss_status_flags
|= VSS_NOMORE
;
709 mutex_unlock(mmd_mutex
);
714 static int com_ff(struct command_context
*cc
)
717 int ret
, backwards
= 0;
722 return -E_COMMAND_SYNTAX
;
723 if (!(ret
= sscanf(cc
->argv
[1], "%u%c", &i
, &c
)))
724 return -E_COMMAND_SYNTAX
;
725 if (ret
> 1 && c
== '-')
726 backwards
= 1; /* jmp backwards */
727 mutex_lock(mmd_mutex
);
728 ret
= -E_NO_AUDIO_FILE
;
729 if (!mmd
->afd
.afhi
.chunks_total
|| !mmd
->afd
.afhi
.seconds_total
)
731 promille
= (1000 * mmd
->current_chunk
) / mmd
->afd
.afhi
.chunks_total
;
733 promille
-= 1000 * i
/ mmd
->afd
.afhi
.seconds_total
;
735 promille
+= 1000 * i
/ mmd
->afd
.afhi
.seconds_total
;
738 if (promille
> 1000) {
739 mmd
->new_vss_status_flags
|= VSS_NEXT
;
742 mmd
->repos_request
= (mmd
->afd
.afhi
.chunks_total
* promille
) / 1000;
743 mmd
->new_vss_status_flags
|= VSS_REPOS
;
744 mmd
->new_vss_status_flags
&= ~VSS_NEXT
;
748 mutex_unlock(mmd_mutex
);
753 static int com_jmp(struct command_context
*cc
)
759 return -E_COMMAND_SYNTAX
;
760 if (sscanf(cc
->argv
[1], "%lu", &i
) <= 0)
761 return -E_COMMAND_SYNTAX
;
762 mutex_lock(mmd_mutex
);
763 ret
= -E_NO_AUDIO_FILE
;
764 if (!mmd
->afd
.afhi
.chunks_total
)
768 PARA_INFO_LOG("jumping to %lu%%\n", i
);
769 mmd
->repos_request
= (mmd
->afd
.afhi
.chunks_total
* i
+ 50) / 100;
770 PARA_INFO_LOG("sent: %lu, offset before jmp: %lu\n",
771 mmd
->chunks_sent
, mmd
->offset
);
772 mmd
->new_vss_status_flags
|= VSS_REPOS
;
773 mmd
->new_vss_status_flags
&= ~VSS_NEXT
;
777 mutex_unlock(mmd_mutex
);
781 static int com_tasks(struct command_context
*cc
)
783 char *tl
= server_get_tasks();
787 ret
= send_sb(&cc
->scc
, tl
, strlen(tl
), SBD_OUTPUT
, false);
792 * check if perms are sufficient to exec a command having perms cmd_perms.
793 * Returns 0 if perms are sufficient, -E_PERM otherwise.
795 static int check_perms(unsigned int perms
, const struct server_command
*cmd_ptr
)
797 PARA_DEBUG_LOG("checking permissions\n");
798 return (cmd_ptr
->perms
& perms
) < cmd_ptr
->perms
? -E_PERM
: 0;
801 static void reset_signals(void)
803 para_sigaction(SIGCHLD
, SIG_IGN
);
804 para_sigaction(SIGINT
, SIG_DFL
);
805 para_sigaction(SIGTERM
, SIG_DFL
);
806 para_sigaction(SIGHUP
, SIG_DFL
);
809 struct connection_features
{
810 bool sideband_requested
;
811 bool aes_ctr128_requested
;
814 static int parse_auth_request(char *buf
, int len
, struct user
**u
,
815 struct connection_features
*cf
)
818 char *p
, *username
, **features
= NULL
;
819 size_t auth_rq_len
= strlen(AUTH_REQUEST_MSG
);
822 memset(cf
, 0, sizeof(*cf
));
823 if (len
< auth_rq_len
+ 2)
824 return -E_AUTH_REQUEST
;
825 if (strncmp(buf
, AUTH_REQUEST_MSG
, auth_rq_len
) != 0)
826 return -E_AUTH_REQUEST
;
827 username
= buf
+ auth_rq_len
;
828 p
= strchr(username
, ' ');
832 return -E_AUTH_REQUEST
;
835 create_argv(p
, ",", &features
);
836 for (i
= 0; features
[i
]; i
++) {
837 if (strcmp(features
[i
], "sideband") == 0)
838 cf
->sideband_requested
= true;
839 else if (strcmp(features
[i
], "aes_ctr128") == 0)
840 cf
->aes_ctr128_requested
= true;
842 ret
= -E_BAD_FEATURE
;
847 PARA_DEBUG_LOG("received auth request for user %s\n", username
);
848 *u
= lookup_user(username
);
855 #define HANDSHAKE_BUFSIZE 4096
857 static int run_command(struct command_context
*cc
, struct iovec
*iov
,
858 const char *peername
)
862 struct server_command
*cmd
;
864 if (iov
->iov_base
== NULL
|| iov
->iov_len
== 0)
867 p
[iov
->iov_len
- 1] = '\0'; /* just to be sure */
868 cmd
= get_cmd_ptr(p
, NULL
);
871 ret
= check_perms(cc
->u
->perms
, cmd
);
874 end
= iov
->iov_base
+ iov
->iov_len
;
875 for (i
= 0; p
< end
; i
++)
878 cc
->argv
= para_malloc((cc
->argc
+ 1) * sizeof(char *));
879 for (i
= 0, p
= iov
->iov_base
; p
< end
; i
++) {
880 cc
->argv
[i
] = para_strdup(p
);
883 cc
->argv
[cc
->argc
] = NULL
;
884 PARA_NOTICE_LOG("calling com_%s() for %s@%s\n", cmd
->name
,
885 cc
->u
->name
, peername
);
886 ret
= cmd
->handler(cc
);
888 mutex_lock(mmd_mutex
);
890 if (ret
>= 0 && (cmd
->perms
& AFS_WRITE
))
892 mutex_unlock(mmd_mutex
);
897 * Perform user authentication and execute a command.
899 * \param fd The file descriptor to send output to.
900 * \param peername Identifies the connecting peer.
902 * Whenever para_server accepts an incoming tcp connection on the port it
903 * listens on, it forks and the resulting child calls this function.
905 * An RSA-based challenge/response is used to authenticate the peer. It that
906 * authentication succeeds, a random session key is generated and sent back to
907 * the peer, encrypted with its RSA public key. From this point on, all
908 * transfers are crypted with this session key.
910 * Next it is checked if the peer supplied a valid server command or a command
911 * for the audio file selector. If yes, and if the user has sufficient
912 * permissions to execute that command, the function calls the corresponding
913 * command handler which does argument checking and further processing.
915 * In order to cope with a DOS attacks, a timeout is set up which terminates
916 * the function if the connection was not authenticated when the timeout
919 * \sa alarm(2), crypt.c, crypt.h
921 __noreturn
void handle_connect(int fd
, const char *peername
)
924 unsigned char rand_buf
[CHALLENGE_SIZE
+ 2 * SESSION_KEY_LEN
];
925 unsigned char challenge_hash
[HASH_SIZE
];
926 char *command
= NULL
, *buf
= para_malloc(HANDSHAKE_BUFSIZE
) /* must be on the heap */;
928 struct command_context cc_struct
= {.peer
= peername
}, *cc
= &cc_struct
;
930 struct connection_features cf
;
934 /* we need a blocking fd here as recv() might return EAGAIN otherwise. */
935 ret
= mark_fd_blocking(fd
);
938 /* send Welcome message */
939 ret
= write_va_buffer(fd
, "This is para_server, version "
940 PACKAGE_VERSION
".\n"
941 "Features: sideband,aes_ctr128\n"
945 /* recv auth request line */
946 ret
= recv_buffer(fd
, buf
, HANDSHAKE_BUFSIZE
);
949 ret
= parse_auth_request(buf
, ret
, &cc
->u
, &cf
);
952 if (!cf
.sideband_requested
) { /* sideband is mandatory */
953 PARA_ERROR_LOG("client did not request sideband\n");
954 ret
= -E_BAD_FEATURE
;
958 get_random_bytes_or_die(rand_buf
, sizeof(rand_buf
));
959 ret
= pub_encrypt(cc
->u
->pubkey
, rand_buf
, sizeof(rand_buf
),
960 (unsigned char *)buf
);
966 * We don't want to reveal our user names, so we send a
967 * challenge to the client even if the user does not exist, and
968 * fail the authentication later.
971 get_random_bytes_or_die((unsigned char *)buf
, numbytes
);
973 PARA_DEBUG_LOG("sending %u byte challenge + session key (%zu bytes)\n",
974 CHALLENGE_SIZE
, numbytes
);
975 ret
= send_sb(&cc
->scc
, buf
, numbytes
, SBD_CHALLENGE
, false);
979 ret
= recv_sb(&cc
->scc
, SBD_CHALLENGE_RESPONSE
,
980 HANDSHAKE_BUFSIZE
, &iov
);
984 numbytes
= iov
.iov_len
;
985 PARA_DEBUG_LOG("received %zu bytes challenge response\n", numbytes
);
990 * The correct response is the hash of the first CHALLENGE_SIZE bytes
991 * of the random data.
994 if (numbytes
!= HASH_SIZE
)
996 hash_function((char *)rand_buf
, CHALLENGE_SIZE
, challenge_hash
);
997 if (memcmp(challenge_hash
, buf
, HASH_SIZE
))
999 /* auth successful */
1001 PARA_INFO_LOG("good auth for %s\n", cc
->u
->name
);
1002 /* init stream cipher keys with the second part of the random buffer */
1003 cc
->scc
.recv
= sc_new(rand_buf
+ CHALLENGE_SIZE
, SESSION_KEY_LEN
,
1004 cf
.aes_ctr128_requested
);
1005 cc
->scc
.send
= sc_new(rand_buf
+ CHALLENGE_SIZE
+ SESSION_KEY_LEN
,
1006 SESSION_KEY_LEN
, cf
.aes_ctr128_requested
);
1007 ret
= send_sb(&cc
->scc
, NULL
, 0, SBD_PROCEED
, false);
1010 ret
= recv_sb(&cc
->scc
, SBD_COMMAND
, MAX_COMMAND_LEN
, &iov
);
1013 ret
= run_command(cc
, &iov
, peername
);
1020 if (send_strerror(cc
, -ret
) >= 0)
1021 send_sb(&cc
->scc
, NULL
, 0, SBD_EXIT__FAILURE
, true);
1023 PARA_NOTICE_LOG("%s\n", para_strerror(-ret
));
1027 mutex_lock(mmd_mutex
);
1028 mmd
->active_connections
--;
1029 mutex_unlock(mmd_mutex
);
1031 ret
= send_sb(&cc
->scc
, NULL
, 0, SBD_EXIT__SUCCESS
, true);
1033 PARA_NOTICE_LOG("%s\n", para_strerror(-ret
));
1035 sc_free(cc
->scc
.recv
);
1036 sc_free(cc
->scc
.send
);
1037 exit(ret
< 0? EXIT_FAILURE
: EXIT_SUCCESS
);