From 6072e7f91726d717eef45c8e50271ca55dc0c20f Mon Sep 17 00:00:00 2001 From: Neil Brown Date: Thu, 29 Mar 2007 13:08:09 +1000 Subject: [PATCH] sm-notify: Try all addresses of a multihomed host. When sending an SM_NOTIFY to multi-homed host, try all the addresses in rotation. After 4 failures on one address, try the next. Signed-off-by: Neil Brown --- utils/statd/sm-notify.c | 45 +++++++++++++++++++++++++---------------- 1 file changed, 28 insertions(+), 17 deletions(-) diff --git a/utils/statd/sm-notify.c b/utils/statd/sm-notify.c index 0eb0b09..a94876d 100644 --- a/utils/statd/sm-notify.c +++ b/utils/statd/sm-notify.c @@ -56,6 +56,7 @@ struct nsm_host { char * name; char * path; nsm_address addr; + struct addrinfo *ai; time_t last_used; time_t send_next; unsigned int timeout; @@ -83,7 +84,7 @@ static void insert_host(struct nsm_host *); struct nsm_host * find_host(uint32_t); static int addr_get_port(nsm_address *); static void addr_set_port(nsm_address *, int); -static int host_lookup(int, const char *, nsm_address *); +static struct addrinfo *host_lookup(int, const char *); void nsm_log(int fac, const char *fmt, ...); static int record_pid(); static void drop_privs(void); @@ -225,12 +226,14 @@ notify(void) /* Bind source IP if provided on command line */ if (opt_srcaddr) { - if (!host_lookup(AF_INET, opt_srcaddr, &local_addr)) { + struct addrinfo *ai = host_lookup(AF_INET, opt_srcaddr); + if (!ai) { nsm_log(LOG_WARNING, "Not a valid hostname or address: \"%s\"\n", opt_srcaddr); exit(1); } + memcpy(&local_addr, ai->ai_addr, ai->ai_addrlen); /* We know it's IPv4 at this point */ } @@ -322,9 +325,19 @@ notify_host(int sock, struct nsm_host *host) *p++ = htonl(2); /* If we retransmitted 4 times, reset the port to force - * a new portmap lookup (in case statd was restarted) + * a new portmap lookup (in case statd was restarted). + * We also rotate through multiple IP addresses at this + * point. */ if (host->retries >= 4) { + struct addrinfo *hold = host->ai; + struct addrinfo **next = &host->ai; + *next = hold->ai_next; + while ( *next ) + next = & (*next)->ai_next; + *next = hold; + hold->ai_next = NULL; + memcpy(&host->addr, hold->ai_addr, hold->ai_addrlen); addr_set_port(&host->addr, 0); host->retries = 0; } @@ -437,6 +450,7 @@ recv_reply(int sock) free(hp->name); free(hp->path); free(hp); + freeaddrinfo(hp->ai); return; } } @@ -502,7 +516,11 @@ get_hosts(const char *dirname) host = calloc(1, sizeof(*host)); snprintf(path, sizeof(path), "%s/%s", dirname, de->d_name); - if (!host_lookup(AF_UNSPEC, de->d_name, &host->addr)) { + if (stat(path, &stb) < 0) + continue; + + host->ai = host_lookup(AF_UNSPEC, de->d_name); + if (! host->ai) { nsm_log(LOG_WARNING, "%s doesn't seem to be a valid address, skipped", de->d_name); @@ -510,12 +528,11 @@ get_hosts(const char *dirname) continue; } - if (stat(path, &stb) < 0) - continue; host->last_used = stb.st_mtime; host->timeout = NSM_TIMEOUT; host->path = strdup(path); host->name = strdup(de->d_name); + host->retries = 100; /* force address retry */ insert_host(host); host = NULL; @@ -658,25 +675,19 @@ addr_set_port(nsm_address *addr, int port) } } -static int -host_lookup(int af, const char *name, nsm_address *addr) +static struct addrinfo * +host_lookup(int af, const char *name) { struct addrinfo hints, *ai; - int okay = 0; memset(&hints, 0, sizeof(hints)); hints.ai_family = af; + hints.ai_protocol = IPPROTO_UDP; if (getaddrinfo(name, NULL, &hints, &ai) != 0) - return 0; - - if (ai->ai_addrlen < sizeof(*addr)) { - memcpy(addr, ai->ai_addr, ai->ai_addrlen); - okay = 1; - } + return NULL; - freeaddrinfo(ai); - return okay; + return ai; } /* -- 2.39.2