X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=secnet.git;a=blobdiff_plain;f=tun.c;h=3db998f37fcd24d05b910d84111ea779fd9b4fbd;hp=d899f0c6d006219573fc60ef6e3f43943e4ba032;hb=78d458950e6cec7e8fce890362e54e4e9ba5c635;hpb=90a39563035b70196da9c5bdc7c17a63b64449b0

diff --git a/tun.c b/tun.c
index d899f0c..3db998f 100644
--- a/tun.c
+++ b/tun.c
@@ -3,6 +3,7 @@
 #include "netlink.h"
 #include <stdio.h>
 #include <string.h>
+#include <errno.h>
 #include <unistd.h>
 #include <fcntl.h>
 #include <sys/ioctl.h>
@@ -134,11 +135,27 @@ static void tun_afterpoll(void *sst, struct pollfd *fds, int nfds)
 static void tun_deliver_to_kernel(void *sst, struct buffer_if *buf)
 {
     struct tun *st=sst;
+    ssize_t rc;
 
     BUF_ASSERT_USED(buf);
-    /* No error checking, because we'd just throw the packet away
-       anyway if it didn't work. */
-    write(st->fd,buf->start,buf->size);
+    
+    /* Log errors, so we can tell what's going on, but only once a
+       minute, so we don't flood the logs.  Short writes count as
+       errors. */
+    rc = write(st->fd,buf->start,buf->size);
+    if(rc != buf->size) {
+	static struct timeval last_report;
+	if(tv_now_global.tv_sec >= last_report.tv_sec + 60) {
+	    if(rc < 0)
+		Message(M_WARNING,
+			"failed to deliver packet to tun device: %s\n",
+			strerror(errno));
+	    else
+		Message(M_WARNING,
+			"truncated packet delivered to tun device\n");
+	    last_report = tv_now_global;
+	}
+    }
     BUF_FREE(buf);
 }
 
@@ -332,7 +349,7 @@ static void tun_phase_hook(void *sst, uint32_t newphase)
 
     hostaddr=ipaddr_to_string(st->local_address);
     secnetaddr=ipaddr_to_string(st->nl.secnet_address);
-    snprintf(mtu,6,"%d",st->nl.mtu);
+    snprintf(mtu,sizeof(mtu),"%d",st->nl.mtu);
     mtu[5]=0;
 
     switch (st->ifconfig_type) {
@@ -479,10 +496,7 @@ static list_t *tun_create(closure_t *self, struct cloc loc, dict_t *context,
 	    fatal_perror("tun_create: uname");
 	}
 	if (strcmp(u.sysname,"Linux")==0) {
-	    if (u.release[0]=='2' && u.release[1]=='.' && u.release[3]=='.') {
-		if (u.release[2]=='2') st->tun_flavour=TUN_FLAVOUR_BSD;
-		else if (u.release[2]=='4') st->tun_flavour=TUN_FLAVOUR_LINUX;
-	    }
+	    st->tun_flavour=TUN_FLAVOUR_LINUX;
 	} else if (strcmp(u.sysname,"SunOS")==0) {
 	    st->tun_flavour=TUN_FLAVOUR_STREAMS;
 	} else if (strcmp(u.sysname,"FreeBSD")==0