chiark / gitweb /
SECURITY: actually reject messages with improper lengths
[secnet.git] / netlink.c
index 8e843bc..df51d9c 100644 (file)
--- a/netlink.c
+++ b/netlink.c
@@ -97,6 +97,9 @@ their use.
 
 */
 
+#include <string.h>
+#include <assert.h>
+#include <limits.h>
 #include "secnet.h"
 #include "util.h"
 #include "ipaddr.h"
@@ -120,7 +123,7 @@ their use.
 #define ICMP_CODE_TTL_EXCEEDED           0
 
 /* Generic IP checksum routine */
-static inline uint16_t ip_csum(uint8_t *iph,uint32_t count)
+static inline uint16_t ip_csum(uint8_t *iph,int32_t count)
 {
     register uint32_t sum=0;
 
@@ -144,38 +147,39 @@ static inline uint16_t ip_csum(uint8_t *iph,uint32_t count)
  *      By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by
  *      Arnt Gulbrandsen.
  */
-static inline uint16_t ip_fast_csum(uint8_t *iph, uint32_t ihl) {
+static inline uint16_t ip_fast_csum(uint8_t *iph, int32_t ihl) {
     uint32_t sum;
 
-    __asm__ __volatile__("
-            movl (%1), %0
-            subl $4, %2
-            jbe 2f
-            addl 4(%1), %0
-            adcl 8(%1), %0
-            adcl 12(%1), %0
-1:          adcl 16(%1), %0
-            lea 4(%1), %1
-            decl %2
-            jne 1b
-            adcl $0, %0
-            movl %0, %2
-            shrl $16, %0
-            addw %w2, %w0
-            adcl $0, %0
-            notl %0
-2:
-            "
+    __asm__ __volatile__(
+            "movl (%1), %0      ;\n"
+            "subl $4, %2        ;\n"
+            "jbe 2f             ;\n"
+            "addl 4(%1), %0     ;\n"
+            "adcl 8(%1), %0     ;\n"
+            "adcl 12(%1), %0    ;\n"
+"1:         adcl 16(%1), %0     ;\n"
+            "lea 4(%1), %1      ;\n"
+            "decl %2            ;\n"
+            "jne 1b             ;\n"
+            "adcl $0, %0        ;\n"
+            "movl %0, %2        ;\n"
+            "shrl $16, %0       ;\n"
+            "addw %w2, %w0      ;\n"
+            "adcl $0, %0        ;\n"
+            "notl %0            ;\n"
+"2:                             ;\n"
         /* Since the input registers which are loaded with iph and ipl
            are modified, we must also specify them as outputs, or gcc
            will assume they contain their original values. */
         : "=r" (sum), "=r" (iph), "=r" (ihl)
-        : "1" (iph), "2" (ihl));
+        : "1" (iph), "2" (ihl)
+       : "memory");
     return sum;
 }
 #else
-static inline uint16_t ip_fast_csum(uint8_t *iph, uint32_t ihl)
+static inline uint16_t ip_fast_csum(uint8_t *iph, int32_t ihl)
 {
+    assert(ihl < INT_MAX/4);
     return ip_csum(iph,ihl*4);
 }
 #endif
@@ -261,7 +265,7 @@ static struct icmphdr *netlink_icmp_tmpl(struct netlink *st,
 /* Fill in the ICMP checksum field correctly */
 static void netlink_icmp_csum(struct icmphdr *h)
 {
-    uint32_t len;
+    int32_t len;
 
     len=ntohs(h->iph.tot_len)-(4*h->iph.ihl);
     h->check=0;
@@ -383,7 +387,7 @@ static void netlink_icmp_simple(struct netlink *st, struct buffer_if *buf,
 static bool_t netlink_check(struct netlink *st, struct buffer_if *buf)
 {
     struct iphdr *iph=(struct iphdr *)buf->start;
-    uint32_t len;
+    int32_t len;
 
     if (iph->ihl < 5 || iph->version != 4) return False;
     if (buf->size < iph->ihl*4) return False;
@@ -497,18 +501,19 @@ static void netlink_packet_deliver(struct netlink *st,
            netlink_icmp_simple(st,buf,client,ICMP_TYPE_UNREACHABLE,
                                ICMP_CODE_NET_PROHIBITED);
            BUF_FREE(buf);
-       }
-       if (best_quality>0) {
-           /* XXX Fragment if required */
-           st->routes[best_match]->deliver(
-               st->routes[best_match]->dst, buf);
-           st->routes[best_match]->outcount++;
-           BUF_ASSERT_FREE(buf);
        } else {
-           /* Generate ICMP destination unreachable */
-           netlink_icmp_simple(st,buf,client,ICMP_TYPE_UNREACHABLE,
-                               ICMP_CODE_NET_UNREACHABLE); /* client==NULL */
-           BUF_FREE(buf);
+           if (best_quality>0) {
+               /* XXX Fragment if required */
+               st->routes[best_match]->deliver(
+                   st->routes[best_match]->dst, buf);
+               st->routes[best_match]->outcount++;
+               BUF_ASSERT_FREE(buf);
+           } else {
+               /* Generate ICMP destination unreachable */
+               netlink_icmp_simple(st,buf,client,ICMP_TYPE_UNREACHABLE,
+                                   ICMP_CODE_NET_UNREACHABLE); /* client==NULL */
+               BUF_FREE(buf);
+           }
        }
     }
     BUF_ASSERT_FREE(buf);
@@ -691,7 +696,7 @@ static void netlink_set_quality(void *sst, uint32_t quality)
 static void netlink_output_subnets(struct netlink *st, uint32_t loglevel,
                                   struct subnet_list *snets)
 {
-    uint32_t i;
+    int32_t i;
     string_t net;
 
     for (i=0; i<snets->entries; i++) {
@@ -720,14 +725,15 @@ static void netlink_dump_routes(struct netlink *st, bool_t requested)
        for (i=0; i<st->n_clients; i++) {
            netlink_output_subnets(st,c,st->routes[i]->subnets);
            Message(c,"-> tunnel %s (%s,mtu %d,%s routes,%s,"
-                   "quality %d,use %d)\n",
+                   "quality %d,use %d,pri %lu)\n",
                    st->routes[i]->name,
                    st->routes[i]->up?"up":"down",
                    st->routes[i]->mtu,
                    st->routes[i]->options&OPT_SOFTROUTE?"soft":"hard",
                    st->routes[i]->options&OPT_ALLOWROUTE?"free":"restricted",
                    st->routes[i]->link_quality,
-                   st->routes[i]->outcount);
+                   st->routes[i]->outcount,
+                   (unsigned long)st->routes[i]->priority);
        }
        net=ipaddr_to_string(st->secnet_address);
        Message(c,"%s/32 -> netlink \"%s\" (use %d)\n",
@@ -758,17 +764,19 @@ static void netlink_phase_hook(void *sst, uint32_t new_phase)
 {
     struct netlink *st=sst;
     struct netlink_client *c;
-    uint32_t i;
+    int32_t i;
 
     /* All the networks serviced by the various tunnels should now
      * have been registered.  We build a routing table by sorting the
      * clients by priority.  */
-    st->routes=safe_malloc(st->n_clients*sizeof(*st->routes),
-                          "netlink_phase_hook");
+    st->routes=safe_malloc_ary(sizeof(*st->routes),st->n_clients,
+                              "netlink_phase_hook");
     /* Fill the table */
     i=0;
-    for (c=st->clients; c; c=c->next)
+    for (c=st->clients; c; c=c->next) {
+       assert(i<INT_MAX);
        st->routes[i++]=c;
+    }
     /* Sort the table in descending order of priority */
     qsort(st->routes,st->n_clients,sizeof(*st->routes),
          netlink_compare_client_priority);
@@ -804,7 +812,7 @@ static bool_t netlink_inst_check_config(void *sst, struct buffer_if *buf)
     return True;
 }
 
-static void netlink_inst_set_mtu(void *sst, uint32_t new_mtu)
+static void netlink_inst_set_mtu(void *sst, int32_t new_mtu)
 {
     struct netlink_client *c=sst;
 
@@ -812,8 +820,8 @@ static void netlink_inst_set_mtu(void *sst, uint32_t new_mtu)
 }
 
 static void netlink_inst_reg(void *sst, netlink_deliver_fn *deliver, 
-                            void *dst, uint32_t max_start_pad,
-                            uint32_t max_end_pad)
+                            void *dst, int32_t max_start_pad,
+                            int32_t max_end_pad)
 {
     struct netlink_client *c=sst;
     struct netlink *st=c->nst;
@@ -840,7 +848,8 @@ static closure_t *netlink_inst_create(struct netlink *st,
     struct netlink_client *c;
     string_t name;
     struct ipset *networks;
-    uint32_t options,priority,mtu;
+    uint32_t options,priority;
+    int32_t mtu;
     list_t *l;
 
     name=dict_read_string(dict, "name", True, st->name, loc);
@@ -900,7 +909,7 @@ static closure_t *netlink_inst_create(struct netlink *st,
     c->deliver=NULL;
     c->dst=NULL;
     c->name=name;
-    c->link_quality=LINK_QUALITY_DOWN;
+    c->link_quality=LINK_QUALITY_UNUSED;
     c->mtu=mtu?mtu:st->mtu;
     c->options=options;
     c->outcount=0;
@@ -908,6 +917,7 @@ static closure_t *netlink_inst_create(struct netlink *st,
     c->kup=False;
     c->next=st->clients;
     st->clients=c;
+    assert(st->n_clients < INT_MAX);
     st->n_clients++;
 
     return &c->cl;
@@ -935,7 +945,7 @@ static list_t *netlink_inst_apply(closure_t *self, struct cloc loc,
 
 netlink_deliver_fn *netlink_init(struct netlink *st,
                                 void *dst, struct cloc loc,
-                                dict_t *dict, string_t description,
+                                dict_t *dict, cstring_t description,
                                 netlink_route_fn *set_routes,
                                 netlink_deliver_fn *to_host)
 {
@@ -1064,7 +1074,6 @@ static list_t *null_apply(closure_t *self, struct cloc loc, dict_t *context,
     return new_closure(&st->nl.cl);
 }
 
-init_module netlink_module;
 void netlink_module(dict_t *dict)
 {
     add_closure(dict,"null-netlink",null_apply);