X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=secnet.git;a=blobdiff_plain;f=slip.c;h=d8b32d8dbda79b5ad8ad4432be2adb4d3a166a10;hp=5eb8dbdb1239e72698eb52d0f53d108af2e2f607;hb=ec2ae5fa0ae79baedb567ad18e09e17305aa89d1;hpb=3abd18e85781e00e2b7fc641f29c99e130238abf

diff --git a/slip.c b/slip.c
index 5eb8dbd..d8b32d8 100644
--- a/slip.c
+++ b/slip.c
@@ -27,7 +27,6 @@ struct slip {
     bool_t ignoring_packet; /* If this packet was corrupt or overlong,
 			       we ignore everything up to the next END */
     netlink_deliver_fn *netlink_to_tunnel;
-    uint32_t local_address;
 };
 
 /* Generic SLIP mangling code */
@@ -79,6 +78,9 @@ static void slip_unstuff(struct slip *st, uint8_t *buf, uint32_t l)
 	int outputchr;
 	enum { OUTPUT_END = 256, OUTPUT_NOTHING = 257 };
 
+	if (!st->buff->size)
+	    buffer_init(st->buff,calculate_max_start_pad());
+
 	if (st->pending_esc) {
 	    st->pending_esc=False;
 	    switch(buf[i]) {
@@ -115,7 +117,7 @@ static void slip_unstuff(struct slip *st, uint8_t *buf, uint32_t l)
 	if (st->ignoring_packet) {
 	    if (outputchr == OUTPUT_END) {
 		st->ignoring_packet=False;
-		buffer_init(st->buff,calculate_max_start_pad());
+		st->buff->size=0;
 	    }
 	} else {
 	    if (outputchr == OUTPUT_END) {
@@ -123,9 +125,9 @@ static void slip_unstuff(struct slip *st, uint8_t *buf, uint32_t l)
 		    st->netlink_to_tunnel(&st->nl,st->buff);
 		    BUF_ALLOC(st->buff,"userv_afterpoll");
 		}
-		buffer_init(st->buff,calculate_max_start_pad());
+		st->buff->size=0;
 	    } else if (outputchr != OUTPUT_NOTHING) {
-		if (st->buff->size < st->buff->len) {
+		if (buf_remaining_space(st->buff)) {
 		    buf_append_uint8(st->buff,outputchr);
 		} else {
 		    Message(M_WARNING, "userv_afterpoll: dropping overlong"
@@ -144,8 +146,6 @@ static void slip_init(struct slip *st, struct cloc loc, dict_t *dict,
 	netlink_init(&st->nl,st,loc,dict,
 		     "netlink-userv-ipif",NULL,to_host);
     st->buff=find_cl_if(dict,"buffer",CL_BUFFER,True,"name",loc);
-    st->local_address=string_item_to_ipaddr(
-	dict_find_item(dict,"local-address", True, name, loc),"netlink");
     BUF_ALLOC(st->buff,"slip_init");
     st->pending_esc=False;
     st->ignoring_packet=False;
@@ -210,6 +210,14 @@ static void userv_deliver_to_kernel(void *sst, struct buffer_if *buf)
 {
     struct userv *st=sst;
 
+    if (buf->size > st->slip.nl.mtu) {
+	Message(M_ERR,"%s: packet of size %"PRIu32" exceeds mtu %"PRIu32":"
+		" cannot be injected into kernel, dropped\n",
+		st->slip.nl.name, buf->size, st->slip.nl.mtu);
+	BUF_FREE(buf);
+	return;
+    }
+
     slip_stuff(&st->slip,buf,st->txfd);
 }
 
@@ -254,7 +262,6 @@ static void userv_entry(void *sst)
     dup2(st->in,0);
     dup2(st->out,1);
 
-    /* XXX close all other fds */
     setsid();
     /* XXX We really should strdup() all of argv[] but because we'll just
        exit anyway if execvp() fails it doesn't seem worth bothering. */
@@ -265,10 +272,9 @@ static void userv_entry(void *sst)
 
 static void userv_invoke_userv(struct userv *st)
 {
-    struct userv_entry_rec *er;
+    struct userv_entry_rec er[1];
     int c_stdin[2];
     int c_stdout[2];
-    string_t addrs;
     string_t nets;
     string_t s;
     struct netlink_client *r;
@@ -284,9 +290,9 @@ static void userv_invoke_userv(struct userv *st)
     /* This is where we actually invoke userv - all the networks we'll
        be using should already have been registered. */
 
-    addrs=safe_malloc(512,"userv_invoke_userv:addrs");
-    snprintf(addrs,512,"%s,%s,%d,slip",
-	     ipaddr_to_string(st->slip.local_address),
+    char addrs[512];
+    snprintf(addrs,sizeof(addrs),"%s,%s,%d,slip",
+	     ipaddr_to_string(st->slip.nl.local_address),
 	     ipaddr_to_string(st->slip.nl.secnet_address),st->slip.nl.mtu);
 
     allnets=ipset_new();
@@ -307,7 +313,6 @@ static void userv_invoke_userv(struct userv *st)
 	s=subnet_to_string(snets->list[i]);
 	strcat(nets,s);
 	strcat(nets,",");
-	free(s);
     }
     nets[strlen(nets)-1]=0;
     subnet_list_free(snets);
@@ -318,17 +323,11 @@ static void userv_invoke_userv(struct userv *st)
     st->slip.pending_esc=False;
 
     /* Invoke userv */
-    if (pipe(c_stdin)!=0) {
-	fatal_perror("userv_invoke_userv: pipe(c_stdin)");
-    }
-    if (pipe(c_stdout)!=0) {
-	fatal_perror("userv_invoke_userv: pipe(c_stdout)");
-    }
+    pipe_cloexec(c_stdin);
+    pipe_cloexec(c_stdout);
     st->txfd=c_stdin[1];
     st->rxfd=c_stdout[0];
 
-    er=safe_malloc(sizeof(*r),"userv_invoke_userv: er");
-
     er->in=c_stdin[0];
     er->out=c_stdout[1];
     /* The arguments are:
@@ -337,7 +336,8 @@ static void userv_invoke_userv(struct userv *st)
        service-name
        local-addr,secnet-addr,mtu,protocol
        route1,route2,... */
-    er->argv=safe_malloc(sizeof(*er->argv)*6,"userv_invoke_userv:argv");
+    const char *er_argv[6];
+    er->argv=er_argv;
     er->argv[0]=st->userv_path;
     er->argv[1]=st->service_user;
     er->argv[2]=st->service_name;
@@ -350,9 +350,6 @@ static void userv_invoke_userv(struct userv *st)
 			er, st, st->slip.nl.name);
     close(er->in);
     close(er->out);
-    free(er->argv);
-    free(er);
-    free(addrs);
     free(nets);
     Message(M_INFO,"%s: userv-ipif pid is %d\n",st->slip.nl.name,st->pid);
     /* Read a single character from the pipe to confirm userv-ipif is