chiark / gitweb /
comm etc.: Provide comm_addr_equal
[secnet.git] / udp.c
diff --git a/udp.c b/udp.c
index 1e637b6..477dea3 100644 (file)
--- a/udp.c
+++ b/udp.c
@@ -19,6 +19,7 @@
 #include <netinet/in.h>
 #include <arpa/inet.h>
 #include "util.h"
+#include "magic.h"
 #include "unaligned.h"
 #include "ipaddr.h"
 #include "magic.h"
@@ -39,37 +40,21 @@ struct udp {
     closure_t cl;
     struct comm_if ops;
     struct cloc loc;
-    uint32_t addr;
-    uint16_t port;
+    union iaddr addr;
     int fd;
     string_t authbind;
     struct buffer_if *rbuf;
     struct notify_list *notify;
     bool_t use_proxy;
-    struct sockaddr_in proxy;
+    union iaddr proxy;
 };
 
-static const char *saddr_to_string(const struct sockaddr_in *sin) {
-    static char bufs[2][100];
-    static int b;
-
-    b ^= 1;
-    snprintf(bufs[b], sizeof(bufs[b]), "[%s]:%d",
-            inet_ntoa(sin->sin_addr),
-            ntohs(sin->sin_port));
-    return bufs[b];
-}
-
 static const char *addr_to_string(void *commst, const struct comm_addr *ca) {
     struct udp *st=commst;
     static char sbuf[100];
 
-    struct sockaddr_in la;
-    la.sin_addr.s_addr=htonl(st->addr);
-    la.sin_port=htons(st->port);
-
     snprintf(sbuf, sizeof(sbuf), "udp:%s-%s",
-            saddr_to_string(&la), saddr_to_string(&ca->sin));
+            iaddr_to_string(&st->addr), iaddr_to_string(&ca->ia));
     return sbuf;
 }
 
@@ -90,7 +75,7 @@ static int udp_beforepoll(void *state, struct pollfd *fds, int *nfds_io,
 static void udp_afterpoll(void *state, struct pollfd *fds, int nfds)
 {
     struct udp *st=state;
-    struct sockaddr_in from;
+    union iaddr from;
     socklen_t fromlen;
     struct notify_list *n;
     bool_t done;
@@ -98,34 +83,34 @@ static void udp_afterpoll(void *state, struct pollfd *fds, int nfds)
 
     if (nfds && (fds->revents & POLLIN)) {
        do {
-           FILLZERO(from);
            fromlen=sizeof(from);
            BUF_ASSERT_FREE(st->rbuf);
            BUF_ALLOC(st->rbuf,"udp_afterpoll");
            buffer_init(st->rbuf,calculate_max_start_pad());
-           rv=recvfrom(st->fd, st->rbuf->start, st->rbuf->len, 0,
-                       (struct sockaddr *)&from, &fromlen);
+           rv=recvfrom(st->fd, st->rbuf->start,
+                       buf_remaining_space(st->rbuf),
+                       0, &from.sa, &fromlen);
            if (rv>0) {
                st->rbuf->size=rv;
                if (st->use_proxy) {
                    /* Check that the packet came from our poxy server;
                       we shouldn't be contacted directly by anybody else
                       (since they can trivially forge source addresses) */
-                   if (memcmp(&from.sin_addr,&st->proxy.sin_addr,4)!=0 ||
-                       memcmp(&from.sin_port,&st->proxy.sin_port,2)!=0) {
+                   if (!iaddr_equal(&from,&st->proxy)) {
                        Message(M_INFO,"udp: received packet that's not "
                                "from the proxy\n");
                        BUF_FREE(st->rbuf);
                        continue;
                    }
-                   memcpy(&from.sin_addr,buf_unprepend(st->rbuf,4),4);
+                   /* proxy protocol supports ipv4 transport only */
+                   from.sa.sa_family=AF_INET;
+                   memcpy(&from.sin.sin_addr,buf_unprepend(st->rbuf,4),4);
                    buf_unprepend(st->rbuf,2);
-                   memcpy(&from.sin_port,buf_unprepend(st->rbuf,2),2);
+                   memcpy(&from.sin.sin_port,buf_unprepend(st->rbuf,2),2);
                }
                struct comm_addr ca;
-               FILLZERO(ca);
                ca.comm=&st->ops;
-               ca.sin=from;
+               ca.ia=from;
                done=False;
                for (n=st->notify; n; n=n->next) {
                    if (n->fn(n->state, st->rbuf, &ca)) {
@@ -195,15 +180,21 @@ static bool_t udp_sendmsg(void *commst, struct buffer_if *buf,
 
     if (st->use_proxy) {
        sa=buf_prepend(buf,8);
-       memcpy(sa,&dest->sin.sin_addr,4);
+       if (dest->ia.sa.sa_family != AF_INET) {
+           Message(M_INFO,
+               "udp: proxy means dropping outgoing non-IPv4 packet to %s\n",
+                   iaddr_to_string(&dest->ia));
+           return False;
+       }
+       memcpy(sa,&dest->ia.sin.sin_addr,4);
        memset(sa+4,0,4);
-       memcpy(sa+6,&dest->sin.sin_port,2);
-       sendto(st->fd,sa,buf->size+8,0,(struct sockaddr *)&st->proxy,
-              sizeof(st->proxy));
+       memcpy(sa+6,&dest->ia.sin.sin_port,2);
+       sendto(st->fd,sa,buf->size+8,0,&st->proxy.sa,
+              iaddr_socklen(&st->proxy));
        buf_unprepend(buf,8);
     } else {
        sendto(st->fd, buf->start, buf->size, 0,
-              (struct sockaddr *)&dest->sin, sizeof(dest->sin));
+              &dest->ia.sa, iaddr_socklen(&dest->ia));
     }
 
     return True;
@@ -212,7 +203,7 @@ static bool_t udp_sendmsg(void *commst, struct buffer_if *buf,
 static void udp_phase_hook(void *sst, uint32_t new_phase)
 {
     struct udp *st=sst;
-    struct sockaddr_in addr;
+    union iaddr addr;
 
     st->fd=socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
     if (st->fd<0) {
@@ -222,15 +213,9 @@ static void udp_phase_hook(void *sst, uint32_t new_phase)
        fatal_perror("udp (%s:%d): fcntl(set O_NONBLOCK)",
                     st->loc.file,st->loc.line);
     }
-    if (fcntl(st->fd, F_SETFD, FD_CLOEXEC)==-1) {
-       fatal_perror("udp (%s:%d): fcntl(set FD_CLOEXEC)",
-                    st->loc.file,st->loc.line);
-    }
+    setcloexec(st->fd);
 
-    FILLZERO(addr);
-    addr.sin_family=AF_INET;
-    addr.sin_addr.s_addr=htonl(st->addr);
-    addr.sin_port=htons(st->port);
+    addr=st->addr;
     if (st->authbind) {
        pid_t c;
        int status;
@@ -243,8 +228,15 @@ static void udp_phase_hook(void *sst, uint32_t new_phase)
        }
        if (c==0) {
            char *argv[4], addrstr[9], portstr[5];
-           sprintf(addrstr,"%08lX",(long)addr.sin_addr.s_addr);
-           sprintf(portstr,"%04X",addr.sin_port);
+           switch (addr.sa.sa_family) {
+           case AF_INET:
+               sprintf(addrstr,"%08lX",(long)addr.sin.sin_addr.s_addr);
+               sprintf(portstr,"%04X",addr.sin.sin_port);
+               break;
+           default:
+               fatal("udp (%s:%d): unsupported address family for authbind",
+                     st->loc.file,st->loc.line);
+           }
            argv[0]=st->authbind;
            argv[1]=addrstr;
            argv[2]=portstr;
@@ -266,7 +258,7 @@ static void udp_phase_hook(void *sst, uint32_t new_phase)
                  st->loc.line, WEXITSTATUS(status));
        }
     } else {
-       if (bind(st->fd, (struct sockaddr *)&addr, sizeof(addr))!=0) {
+       if (bind(st->fd, &addr.sa, iaddr_socklen(&addr))!=0) {
            fatal_perror("udp (%s:%d): bind",st->loc.file,st->loc.line);
        }
     }
@@ -294,7 +286,6 @@ static list_t *udp_apply(closure_t *self, struct cloc loc, dict_t *context,
     st->ops.release_notify=release_notify;
     st->ops.sendmsg=udp_sendmsg;
     st->ops.addr_to_string=addr_to_string;
-    st->port=0;
     st->use_proxy=False;
 
     i=list_elem(args,0);
@@ -303,27 +294,27 @@ static list_t *udp_apply(closure_t *self, struct cloc loc, dict_t *context,
     }
     d=i->data.dict;
 
+    st->addr.sa.sa_family=AF_INET;
     j=dict_find_item(d,"address",False,"udp",st->loc);
-    st->addr=j?string_item_to_ipaddr(j, "udp"):INADDR_ANY;
-    st->port=dict_read_number(d,"port",True,"udp",st->loc,0);
+    st->addr.sin.sin_addr.s_addr=j?string_item_to_ipaddr(j, "udp"):INADDR_ANY;
+    st->addr.sin.sin_port=dict_read_number(d,"port",True,"udp",st->loc,0);
     st->rbuf=find_cl_if(d,"buffer",CL_BUFFER,True,"udp",st->loc);
     st->authbind=dict_read_string(d,"authbind",False,"udp",st->loc);
     l=dict_lookup(d,"proxy");
     if (l) {
        st->use_proxy=True;
-       FILLZERO(st->proxy);
-       st->proxy.sin_family=AF_INET;
+       st->proxy.sa.sa_family=AF_INET;
        i=list_elem(l,0);
        if (!i || i->type!=t_string) {
            cfgfatal(st->loc,"udp","proxy must supply ""addr"",port\n");
        }
        a=string_item_to_ipaddr(i,"proxy");
-       st->proxy.sin_addr.s_addr=htonl(a);
+       st->proxy.sin.sin_addr.s_addr=htonl(a);
        i=list_elem(l,1);
        if (!i || i->type!=t_number) {
            cfgfatal(st->loc,"udp","proxy must supply ""addr"",port\n");
        }
-       st->proxy.sin_port=htons(i->data.number);
+       st->proxy.sin.sin_port=htons(i->data.number);
     }
 
     update_max_start_pad(&comm_max_start_pad, st->use_proxy ? 8 : 0);