| 1 | /* |
| 2 | * pinger.c: centralised module that deals with sending TS_PING |
| 3 | * keepalives, to avoid replicating this code in multiple backends. |
| 4 | */ |
| 5 | |
| 6 | #include "putty.h" |
| 7 | |
| 8 | struct pinger_tag { |
| 9 | int interval; |
| 10 | int pending; |
| 11 | long next; |
| 12 | Backend *back; |
| 13 | void *backhandle; |
| 14 | }; |
| 15 | |
| 16 | static void pinger_schedule(Pinger pinger); |
| 17 | |
| 18 | static void pinger_timer(void *ctx, long now) |
| 19 | { |
| 20 | Pinger pinger = (Pinger)ctx; |
| 21 | |
| 22 | if (pinger->pending && now - pinger->next >= 0) { |
| 23 | pinger->back->special(pinger->backhandle, TS_PING); |
| 24 | pinger->pending = FALSE; |
| 25 | pinger_schedule(pinger); |
| 26 | } |
| 27 | } |
| 28 | |
| 29 | static void pinger_schedule(Pinger pinger) |
| 30 | { |
| 31 | int next; |
| 32 | |
| 33 | if (!pinger->interval) { |
| 34 | pinger->pending = FALSE; /* cancel any pending ping */ |
| 35 | return; |
| 36 | } |
| 37 | |
| 38 | next = schedule_timer(pinger->interval * TICKSPERSEC, |
| 39 | pinger_timer, pinger); |
| 40 | if (!pinger->pending || next < pinger->next) { |
| 41 | pinger->next = next; |
| 42 | pinger->pending = TRUE; |
| 43 | } |
| 44 | } |
| 45 | |
| 46 | Pinger pinger_new(Config *cfg, Backend *back, void *backhandle) |
| 47 | { |
| 48 | Pinger pinger = snew(struct pinger_tag); |
| 49 | |
| 50 | pinger->interval = cfg->ping_interval; |
| 51 | pinger->pending = FALSE; |
| 52 | pinger->back = back; |
| 53 | pinger->backhandle = backhandle; |
| 54 | pinger_schedule(pinger); |
| 55 | |
| 56 | return pinger; |
| 57 | } |
| 58 | |
| 59 | void pinger_reconfig(Pinger pinger, Config *oldcfg, Config *newcfg) |
| 60 | { |
| 61 | if (oldcfg->ping_interval != newcfg->ping_interval) { |
| 62 | pinger->interval = newcfg->ping_interval; |
| 63 | pinger_schedule(pinger); |
| 64 | } |
| 65 | } |
| 66 | |
| 67 | void pinger_free(Pinger pinger) |
| 68 | { |
| 69 | expire_timer_context(pinger); |
| 70 | sfree(pinger); |
| 71 | } |