From d7c62ad55ce5be32fe37563cf390907278fb44a2 Mon Sep 17 00:00:00 2001 From: df Date: Mon, 27 Jul 2020 15:18:17 +0100 Subject: [PATCH] Add signal handling: SIGUSR1 - dump cache; SIGHUP - restart server --- mdns.h | 1 + mdnsd.c | 43 +++++++++++++++++++++++++++++-------------- testmdnsd.c | 44 +++++++++++++++++++++++++++++++++++++++----- 3 files changed, 69 insertions(+), 19 deletions(-) diff --git a/mdns.h b/mdns.h index 45aff88..0a2c00d 100644 --- a/mdns.h +++ b/mdns.h @@ -86,6 +86,7 @@ void mdns_show_meminfo(void); #else #define DEBUG_PRINTF(...) ((void) 0) #endif +#define MDNS_RR_DEBUG_PRINTF(...) printf(__VA_ARGS__) struct rr_data_srv { diff --git a/mdnsd.c b/mdnsd.c index 15a5a85..a0954e2 100644 --- a/mdnsd.c +++ b/mdnsd.c @@ -128,6 +128,7 @@ struct mdnsd { int sockfd; int notify_pipe[2]; int stop_flag; + int dump_cache; int sendmsg_requested; int domain; @@ -174,13 +175,13 @@ static void log_message(int loglevel, char *fmt_str, ...) { fprintf(stderr, "%s\n", buf); } -#ifdef MDNSD_RR_DEBUG +//#ifdef MDNSD_RR_DEBUG static void print_rr_entry(struct rr_entry *rr_e) { char *str1, *str2; if (!rr_e) { - DEBUG_PRINTF("ERROR: No RR Entry\n"); + MDNS_RR_DEBUG_PRINTF("ERROR: No RR Entry\n"); return; } @@ -198,12 +199,12 @@ static void print_rr_entry(struct rr_entry *rr_e) str2 = NULL; } - DEBUG_PRINTF("type:%s, ttl=%d, time=%d, ca_fl=%d, rr_class=%d, name=[%s]", rr_get_type_name(rr_e->type), rr_e->ttl, (unsigned int)(time(NULL) - rr_e->update_time), (int)rr_e->cache_flush, rr_e->rr_class, str1 ? str1 : "NULL"); + MDNS_RR_DEBUG_PRINTF("type:%s, ttl=%d, time=%d, ca_fl=%d, rr_class=%d, name=[%s]", rr_get_type_name(rr_e->type), rr_e->ttl, (unsigned int)(time(NULL) - rr_e->update_time), (int)rr_e->cache_flush, rr_e->rr_class, str1 ? str1 : "NULL"); if (rr_e->type == RR_SRV || rr_e->type == RR_PTR) { - DEBUG_PRINTF(", target=[%s]\n", str2 ? str2 : "NULL"); + MDNS_RR_DEBUG_PRINTF(", target=[%s]\n", str2 ? str2 : "NULL"); } else { - DEBUG_PRINTF("\n"); + MDNS_RR_DEBUG_PRINTF("\n"); } if (str1) { @@ -216,15 +217,17 @@ static void print_rr_entry(struct rr_entry *rr_e) static void print_cache(struct mdnsd *svr) { - DEBUG_PRINTF("\n"); - DEBUG_PRINTF(" Multicast DNS Cache\n"); + MDNS_RR_DEBUG_PRINTF("\n"); + MDNS_RR_DEBUG_PRINTF(" Multicast DNS Cache\n"); for (struct rr_group *group = svr->cache; group; group = group->next) { char *pname = group->name? nlabel_to_str(group->name): NULL; - DEBUG_PRINTF("==================================================\n"); - DEBUG_PRINTF(" Group: %s\n", pname ? pname : "Unknown"); - DEBUG_PRINTF("==================================================\n"); + MDNS_RR_DEBUG_PRINTF( + "==================================================\n" + " Group: %s\n" + "==================================================\n", + pname ? pname : "Unknown"); if (pname) { MDNS_FREE(pname); } @@ -236,10 +239,9 @@ static void print_cache(struct mdnsd *svr) } } } - DEBUG_PRINTF("==================================================\n"); - DEBUG_PRINTF("\n"); + MDNS_RR_DEBUG_PRINTF("==================================================\n\n"); } -#endif /* MDNSD_RR_DEBUG */ +//#endif /* MDNSD_RR_DEBUG */ static int check_mdns_domain(const char *name) { @@ -1252,7 +1254,7 @@ static void main_loop(struct mdnsd *svr) { continue; } - DEBUG_PRINTF("data from=%s:%d size=%ld\n", inet_ntoa(fromaddr.sin_addr), (long) recvsize); + DEBUG_PRINTF("data from=%s:%d size=%ld\n", inet_ntoa(fromaddr.sin_addr), ntohl(fromaddr.sin_port), (long) recvsize); struct mdns_pkt *mdns = mdns_parse_pkt(pkt_buffer, recvsize); if (mdns != NULL) { struct sockaddr_in toaddr = fromaddr; @@ -1356,6 +1358,11 @@ static void main_loop(struct mdnsd *svr) { break; /* exit main_loop */ sem_post(&svr->sendmsg_sem); } + + if (svr->dump_cache) { + svr->dump_cache = 0; + print_cache(svr); + } } if (svr->sendmsg_requested && svr->stop_flag) { @@ -1793,6 +1800,7 @@ static int init_mdns_context(int domain) pthread_mutex_init(&g_svr->data_lock, NULL); sem_init(&g_svr->sendmsg_sem, 0, 0); g_svr->sendmsg_requested = 1; + g_svr->dump_cache= 0; /* init thread */ if (pthread_attr_init(&attr) != 0) { @@ -2001,6 +2009,11 @@ static void mdns_cmd_mutex_unlock(void) } } +static void handler_dump_cache(int sig) { + (void)sig; + g_svr->dump_cache = 1; +} + ///////////////////////////////////////////////////// // Public Functions ///////////////////////////////////////////////////// @@ -2043,6 +2056,8 @@ int mdnsd_start(const char *desired_hostname, const char *netif_nameOrAddress) goto out_with_mutex; } + signal(SIGUSR1, handler_dump_cache); + /* success */ result = 0; diff --git a/testmdnsd.c b/testmdnsd.c index a03050c..b3e608c 100644 --- a/testmdnsd.c +++ b/testmdnsd.c @@ -32,6 +32,7 @@ #include #include #include +#include #ifdef _WIN32 #include @@ -275,13 +276,30 @@ void dump_hosts(const struct hostent * hostents) { } } +static void handler_stop(int sig) { + (void)sig; + mdnsd_stop(); +#ifdef WIN32 + winsock_close(); +#endif + exit(0); +} + +volatile static int running; + +static void handler_restart(int sig) { + /* a dummy handler so that sleep() will end early */ + (void)sig; + if (running != 0) + running = 2; +} + int main(int argc, char **argv) { char hostname[0x100], ifname[0x120], fullname[0x108]; struct in_addr saddr; - int notrunning = 1; if (gethostname(hostname, sizeof(hostname) - 1) == -1) { @@ -300,6 +318,21 @@ main(int argc, char **argv) NULL }; + running = 0; + + signal(SIGINT, handler_stop); + signal(SIGTERM, handler_stop); +#if defined(SIGPIPE) + signal(SIGPIPE, SIG_IGN); +#endif +#if defined(SIGQUIT) + signal(SIGQUIT, handler_stop); +#endif +#if defined(SIGHUP) + signal(SIGHUP, handler_restart); +#endif + + for (saddr.s_addr = 0;;sleep(61)) { struct hostent *hp = gethostbyname(hostname); char * ip_addr; @@ -310,8 +343,8 @@ main(int argc, char **argv) return 1; } - if (saddr.s_addr != *(in_addr_t *)(hp->h_addr_list[0])) { - if ((notrunning == 0) && (0 > mdnsd_stop())) { + if (running != 1 || saddr.s_addr != *(in_addr_t *)(hp->h_addr_list[0])) { + if (running && (0 > mdnsd_stop())) { fprintf(stderr, "mdnsd_stop() error\n"); return 1; } @@ -326,7 +359,7 @@ main(int argc, char **argv) fprintf(stderr, "mdnsd_start() error\n"); return 1; } - notrunning = 0; + running = 1; /* service must have FQDN */ if (0 <= mdnsd_register_service( @@ -340,6 +373,7 @@ main(int argc, char **argv) if (0 <= mdnsd_discover_service("_http._tcp.local", 5000, &svcinfo, &numserv)) { + /* allow an extra entry for own host */ struct hostent * hosts = read_hosts(numserv+1); if (!hosts) { fprintf(stderr,"null hosts\n"); @@ -362,7 +396,7 @@ main(int argc, char **argv) } } - if ((notrunning == 0) && (0 > mdnsd_stop())) { + if (running && (0 > mdnsd_stop())) { fprintf(stderr,"mdnsd_stop() error\n"); }