Add a "hack" to report back to the vxi11 service code when a link dies.

It's a hack because linux/glibc's RPC implementation doesn't seem to
have the ability to set a recv error callback. The hack is to add an
extra event to the events poll'd.. that event tells us if the socket
died.

4 files changed, 87 insertions, 14 deletions

diff --git a/libvxi11client/libvxi11client.c b/libvxi11client/libvxi11client.c
index 743168f..0e01809 100644
--- a/libvxi11client/libvxi11client.c
+++ b/libvxi11client/libvxi11client.c
@@ -214,8 +214,10 @@ int vxi11_read(VXI11Context* context, char* buffer, unsigned int bufferlen, bool
 #ifdef DEBUG
 		printf("Got \"%s\" from server\n", resp->data.data_val);
 #endif
-		if (buffer != NULL)
-			strncpy(buffer, resp->data.data_val, (bufferlen < resp->data.data_len ? bufferlen : resp->data.data_len));
+		if (buffer != NULL && resp->data.data_val != NULL) {
+			int lengthtocopy = ((bufferlen - 1) < resp->data.data_len ? (bufferlen - 1) : resp->data.data_len);
+			strncpy(buffer, resp->data.data_val, lengthtocopy);
+		}
 #ifdef DEBUG
 		else
 			printf("Supplied buffer is null!\n");
diff --git a/vxi11_server.c b/vxi11_server.c
index ae8317f..4185542 100644
--- a/vxi11_server.c
+++ b/vxi11_server.c
@@ -47,6 +47,7 @@ static gchar* inthandler = NULL;
 #define LINKLONGSINCEDEADTIMEOUT ((10 * 60) * 1000000) // ten minutes
 typedef struct {
 	int lid;
+	int sock;
 	GTimeVal lastactivity;
 } ActiveLink;
 
@@ -66,6 +67,29 @@ static bool isValidLink(int linkid) {
 	return links[linkid] != NULL;
 }
 
+static void freelink(ActiveLink* link) {
+	links[link->lid] = NULL;
+	globals.Remote.vxi_connections--;
+#ifdef DEBUG
+	printf("link %d destroyed, %d active links\n", link->lid, globals.Remote.vxi_connections);
+#endif
+	g_free(link);
+}
+
+void vxi11_deadsocketcallback(int socket) {
+	int linkid;
+	for (linkid = 0; linkid < SIZEOFARRAY(links); linkid++) {
+		if (links[linkid] != NULL) {
+			if (links[linkid]->sock == socket) {
+#ifdef DEBUG
+				printf("Freeing link %d, socket died\n", linkid);
+#endif
+				freelink(links[linkid]);
+			}
+		}
+	}
+}
+
 // test if a link has expired, this is to avoid dead locks
 static bool linkexpired(ActiveLink* link) {
 	GTimeVal cutoff;
@@ -75,9 +99,7 @@ static bool linkexpired(ActiveLink* link) {
 #ifdef DEBUG
 		printf("Link %d is apparently dead, removing\n", link->lid);
 #endif
-		links[link->lid] = NULL;
-		g_free(link);
-		globals.Remote.vxi_connections--;
+		freelink(link);
 		return true;
 	}
 	else
@@ -171,10 +193,11 @@ create_link_1_svc(Create_LinkParms *argp, struct svc_req *rqstp) {
 			}
 			g_assert(linkid != SIZEOFARRAY(links));
 			link->lid = linkid;
+			link->sock = rqstp->rq_xprt->xp_sock;
 			touchlink(linkid);
 			globals.Remote.vxi_connections++;
 #ifdef DEBUG
-			printf("created link %d, %d active links\n", linkid, globals.Remote.vxi_connections);
+			printf("created link %d(socket %d), %d active links\n", linkid, link->sock, globals.Remote.vxi_connections);
 #endif
 
 			struct sockaddr_in sin;
@@ -184,6 +207,7 @@ create_link_1_svc(Create_LinkParms *argp, struct svc_req *rqstp) {
 			result.abortPort = ntohs(sin.sin_port);
 			result.maxRecvSize = MAXRECV;
 			result.lid = linkid;
+
 		}
 	}
 	return &result;
@@ -468,13 +492,8 @@ destroy_link_1_svc(Device_Link *argp, struct svc_req *rqstp) {
 			unlock();
 		}
 
-		globals.Remote.vxi_connections--;
-#ifdef DEBUG
-		printf("link %d destroyed, %d active links\n", lid, globals.Remote.vxi_connections);
-#endif
+		freelink(links[lid]);
 		result.error = 0;
-		g_free(links[lid]);
-		links[lid] = NULL;
 	}
 
 	return &result;
diff --git a/vxi11_server.h b/vxi11_server.h
index f682f58..5c4450d 100644
--- a/vxi11_server.h
+++ b/vxi11_server.h
@@ -1 +1,2 @@
 void vxi11_fireinterrupt(void);
+void vxi11_deadsocketcallback(int socket);
diff --git a/vxi11_svc.c b/vxi11_svc.c
index edc4212..e5c4b38 100644
--- a/vxi11_svc.c
+++ b/vxi11_svc.c
@@ -1,12 +1,18 @@
+#define  _GNU_SOURCE
+
 #include "vxi11.h"
+#include "vxi11_server.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <rpc/pmap_clnt.h>
 #include <string.h>
 #include <memory.h>
+#include <poll.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
 
+#define	VXI11_DEFAULT_TIMEOUT	1000
+
 #ifndef SIG_PF
 #define SIG_PF void(*)(int)
 #endif
@@ -223,6 +229,51 @@ void vxi_main() {
 		exit(1);
 	}
 
-	svc_run();
-	fprintf(stderr, "%s", "svc_run returned");
+	int i, j;
+	struct pollfd *my_pollfd = NULL;
+	int last_max_pollfd = 0;
+
+	while (1) {
+		int max_pollfd = svc_max_pollfd;
+		if (max_pollfd == 0 && svc_pollfd == NULL)
+			break;
+
+		if (last_max_pollfd != max_pollfd) {
+			struct pollfd *new_pollfd = realloc(my_pollfd, sizeof(struct pollfd) * max_pollfd);
+
+			if (new_pollfd == NULL) {
+				break;
+			}
+
+			my_pollfd = new_pollfd;
+			last_max_pollfd = max_pollfd;
+		}
+
+		for (i = 0; i < max_pollfd; ++i) {
+			my_pollfd[i].fd = svc_pollfd[i].fd;
+			my_pollfd[i].events = svc_pollfd[i].events | POLLRDHUP; // add the "socket is dead" event
+			my_pollfd[i].revents = 0;
+		}
+
+		j = poll(my_pollfd, max_pollfd, VXI11_DEFAULT_TIMEOUT);
+
+		for (i = 0; i < max_pollfd; i++) {
+			if (my_pollfd[i].revents & POLLRDHUP)
+				vxi11_deadsocketcallback(my_pollfd[i].fd);
+		}
+
+		switch (j) {
+			case -1:
+				break;
+			case 0:
+				continue;
+			default:
+				svc_getreq_poll(my_pollfd, i);
+				continue;
+		}
+		break;
+	}
+
+	//svc_run();
+	//fprintf(stderr, "%s", "svc_run returned");
 }