2 * Copyright (C) 2013 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file sync_filter.c Playback synchronization filter. */
9 #include <netinet/in.h>
10 #include <sys/socket.h>
12 #include <sys/types.h>
13 #include <arpa/inet.h>
18 #include "sync_filter.cmdline.h"
23 #include "buffer_tree.h"
29 struct sync_buddy_info
{
37 /* per open/close data */
40 struct sync_buddy_info
*sbi
;
42 struct list_head node
;
45 struct sync_filter_context
{
47 struct list_head buddies
;
48 struct timeval timeout
;
52 struct sync_filter_config
{
53 struct sync_filter_args_info
*conf
;
54 struct sync_buddy_info
*buddy_info
;
57 #define FOR_EACH_BUDDY(_buddy, _list) \
58 list_for_each_entry(_buddy, _list, node)
59 #define FOR_EACH_BUDDY_SAFE(_buddy, _tmp_buddy, _list) \
60 list_for_each_entry_safe(_buddy, _tmp_buddy, _list, node)
62 static void sync_close_buddy(struct sync_buddy
*buddy
)
66 PARA_DEBUG_LOG("closing %s\n", buddy
->sbi
->url
);
71 static void sync_close_buddies(struct sync_filter_context
*ctx
)
73 struct sync_buddy
*buddy
;
75 FOR_EACH_BUDDY(buddy
, &ctx
->buddies
)
76 sync_close_buddy(buddy
);
79 static void sync_close(struct filter_node
*fn
)
81 struct sync_filter_context
*ctx
= fn
->private_data
;
83 sync_close_buddies(ctx
);
84 if (ctx
->listen_fd
>= 0) {
85 close(ctx
->listen_fd
);
89 fn
->private_data
= NULL
;
92 static void sync_free_config(void *conf
)
94 struct sync_filter_config
*sfc
= conf
;
97 for (i
= 0; i
< sfc
->conf
->buddy_given
; i
++) {
98 free(sfc
->buddy_info
[i
].host
);
99 freeaddrinfo(sfc
->buddy_info
[i
].ai
);
101 sync_filter_cmdline_parser_free(sfc
->conf
);
105 static void sync_open(struct filter_node
*fn
)
108 struct sync_filter_config
*sfc
= fn
->conf
;
109 struct sync_buddy
*buddy
;
110 struct sync_filter_context
*ctx
;
114 ctx
= fn
->private_data
= para_calloc(sizeof(*ctx
));
115 INIT_LIST_HEAD(&ctx
->buddies
);
118 /* create socket to listen for incoming packets */
122 NULL
/* no host required */,
124 NULL
/* no flowopts */
127 PARA_ERROR_LOG("could not create UDP listening socket %d\n",
128 sfc
->conf
->port_arg
);
131 ctx
->listen_fd
= ret
;
132 PARA_INFO_LOG("listening on fd %d\n", ctx
->listen_fd
);
134 for (i
= 0; i
< sfc
->conf
->buddy_given
; i
++) {
135 struct sync_buddy_info
*sbi
= sfc
->buddy_info
+ i
;
136 const char *url
= sfc
->conf
->buddy_arg
[i
];
139 /* make buddy udp socket from address info */
141 ret
= makesock_addrinfo(
143 false /* not passive */,
145 NULL
/* no flowopts */
148 PARA_WARNING_LOG("could not make socket for %s\n",
153 ret
= mark_fd_nonblocking(fd
);
155 PARA_ERROR_LOG("unable to set nonblock mode for %s\n",
160 buddy
= para_malloc(sizeof(*buddy
));
163 buddy
->ping_received
= false;
164 para_list_add(&buddy
->node
, &ctx
->buddies
);
166 PARA_INFO_LOG("opened buddy %s on fd %d\n", url
, fd
);
169 PARA_WARNING_LOG("%s\n", para_strerror(-ret
));
173 static int sync_parse_config(int argc
, char **argv
, void **result
)
176 struct sync_filter_config
*sfc
;
177 struct sync_filter_args_info
*conf
= para_malloc(sizeof(*conf
));
179 sync_filter_cmdline_parser(argc
, argv
, conf
); /* exits on error */
180 sfc
= para_calloc(sizeof(*sfc
));
182 n
= conf
->buddy_given
;
183 sfc
->buddy_info
= para_malloc((n
+ 1) * sizeof(*sfc
->buddy_info
));
184 PARA_INFO_LOG("initializing buddy info array of length %d\n", n
);
185 for (i
= 0; i
< n
; i
++) {
186 const char *url
= conf
->buddy_arg
[i
];
187 size_t len
= strlen(url
);
188 char *host
= para_malloc(len
+ 1);
191 struct sync_buddy_info
*sbi
= sfc
->buddy_info
+ i
;
193 if (!parse_url(url
, host
, len
, &port
)) {
195 PARA_ERROR_LOG("could not parse url %s\n", url
);
196 ret
= -ERRNO_TO_PARA_ERROR(EINVAL
);
200 port
= conf
->port_arg
;
201 ret
= lookup_address(IPPROTO_UDP
, false /* not passive */,
204 PARA_ERROR_LOG("host lookup failure for %s\n", url
);
212 sbi
->disabled
= false;
213 PARA_DEBUG_LOG("buddy #%d: %s\n", i
, url
);
219 PARA_ERROR_LOG("%s\n", para_strerror(-ret
));
220 sync_free_config(sfc
);
225 * True if we sent a packet to all budies and received a packet from each
228 static bool sync_complete(struct sync_filter_context
*ctx
)
230 struct sync_buddy
*buddy
;
234 FOR_EACH_BUDDY(buddy
, &ctx
->buddies
)
235 if (!buddy
->sbi
->disabled
&& !buddy
->ping_received
)
240 static void sync_disable_active_buddies(struct sync_filter_context
*ctx
)
242 struct sync_buddy
*buddy
;
244 FOR_EACH_BUDDY(buddy
, &ctx
->buddies
) {
245 if (buddy
->sbi
->disabled
)
247 PARA_NOTICE_LOG("disabling %s\n", buddy
->sbi
->url
);
248 buddy
->sbi
->disabled
= true;
252 static void sync_set_timeout(struct sync_filter_context
*ctx
,
253 struct sync_filter_config
*sfc
)
257 ms2tv(sfc
->conf
->timeout_arg
, &to
);
258 tv_add(now
, &to
, &ctx
->timeout
);
261 static void sync_pre_select(struct sched
*s
, void *context
)
264 struct filter_node
*fn
= context
;
265 struct sync_filter_context
*ctx
= fn
->private_data
;
266 struct sync_filter_config
*sfc
= fn
->conf
;
268 if (list_empty(&ctx
->buddies
))
269 return sched_min_delay(s
);
270 if (ctx
->listen_fd
< 0)
271 return sched_min_delay(s
);
272 ret
= btr_node_status(fn
->btrn
, 0, BTR_NT_INTERNAL
);
274 return sched_min_delay(s
);
275 para_fd_set(ctx
->listen_fd
, &s
->rfds
, &s
->max_fileno
);
278 if (ctx
->timeout
.tv_sec
== 0) { /* must ping buddies */
279 sync_set_timeout(ctx
, sfc
);
280 return sched_min_delay(s
);
282 if (sync_complete(ctx
)) /* push down what we have */
283 return sched_min_delay(s
);
284 sched_request_barrier_or_min_delay(&ctx
->timeout
, s
);
287 static struct sync_buddy
*sync_find_buddy(struct sockaddr
*addr
,
288 struct list_head
*list
)
290 struct sync_buddy
*buddy
;
292 FOR_EACH_BUDDY(buddy
, list
)
293 if (sockaddr_equal(buddy
->sbi
->ai
->ai_addr
, addr
))
298 static int sync_post_select(__a_unused
struct sched
*s
, void *context
)
301 struct filter_node
*fn
= context
;
302 struct sync_filter_context
*ctx
= fn
->private_data
;
303 struct sync_filter_config
*sfc
= fn
->conf
;
304 struct sync_buddy
*buddy
, *tmp
;
306 if (list_empty(&ctx
->buddies
))
308 ret
= -E_SYNC_LISTEN_FD
;
309 if (ctx
->listen_fd
< 0)
311 ret
= btr_node_status(fn
->btrn
, 0, BTR_NT_INTERNAL
);
316 if (ctx
->timeout
.tv_sec
== 0)
317 sync_set_timeout(ctx
, sfc
);
319 if (tv_diff(&ctx
->timeout
, now
, NULL
) < 0) {
320 sync_disable_active_buddies(ctx
);
324 if (!ctx
->ping_sent
) {
325 FOR_EACH_BUDDY_SAFE(buddy
, tmp
, &ctx
->buddies
) {
327 PARA_INFO_LOG("pinging %s (%s)\n",
328 buddy
->sbi
->url
, buddy
->sbi
->disabled
?
329 "disabled" : "enabled");
330 ret
= xwrite(buddy
->fd
, &c
, 1);
331 sync_close_buddy(buddy
);
333 PARA_WARNING_LOG("failed to write to %s: %s\n",
334 buddy
->sbi
->url
, para_strerror(-ret
));
335 list_del(&buddy
->node
);
338 ctx
->ping_sent
= true;
340 if (FD_ISSET(ctx
->listen_fd
, &s
->rfds
)) {
343 struct sockaddr src_addr
;
344 socklen_t len
= sizeof(src_addr
);
345 ret
= recvfrom(ctx
->listen_fd
, &c
, 1, MSG_DONTWAIT
,
348 if (errno
== EAGAIN
|| errno
== EWOULDBLOCK
)
350 ret
= -ERRNO_TO_PARA_ERROR(errno
);
353 buddy
= sync_find_buddy(&src_addr
, &ctx
->buddies
);
355 PARA_NOTICE_LOG("pinged by unknown\n");
358 PARA_DEBUG_LOG("pinged by %s\n", buddy
->sbi
->url
);
359 if (buddy
->sbi
->disabled
) {
360 PARA_NOTICE_LOG("enabling %s\n",
362 buddy
->sbi
->disabled
= false;
364 list_del(&buddy
->node
);
367 if (!sync_complete(ctx
))
370 * Although all enabled buddies are in sync we do not splice out
371 * ourselves immediately. We rather wait until the timout expires,
372 * or the buddy list has become empty. This opens a time window
373 * for disabled buddies to become enabled by sending us a packet.
375 btr_pushdown(fn
->btrn
);
378 ret
= -E_SYNC_COMPLETE
; /* success */
381 PARA_WARNING_LOG("%s\n", para_strerror(-ret
));
383 sync_close_buddies(ctx
);
384 btr_splice_out_node(&fn
->btrn
);
390 * The synchronization filter.
392 * \param f Pointer to the struct to initialize.
394 void sync_filter_init(struct filter
*f
)
396 struct sync_filter_args_info dummy
;
398 sync_filter_cmdline_parser_init(&dummy
);
400 f
->close
= sync_close
;
401 f
->pre_select
= sync_pre_select
;
402 f
->post_select
= sync_post_select
;
403 f
->parse_config
= sync_parse_config
;
404 f
->free_config
= sync_free_config
;
405 f
->help
= (struct ggo_help
)DEFINE_GGO_HELP(sync_filter
);