* optionally bind to a particular local IP address (not implemented
* yet).
*
- * Sites register an interest in local port numbers for receiving
- * packets, and can also send packets. We don't care about the source
- * port number for sending packets.
- *
* Packets are offered to registered receivers in turn. Once one
* accepts it, it isn't offered to any more. */
#include <sys/wait.h>
#include "util.h"
#include "unaligned.h"
+#include "ipaddr.h"
static beforepoll_fn udp_beforepoll;
static afterpoll_fn udp_afterpoll;
static comm_release_notify_fn release_notify;
static comm_sendmsg_fn udp_sendmsg;
-/* The UDP module exports a pure closure which can be used to construct a
- * UDP send/receive module. Arguments:
- */
-
struct notify_list {
comm_notify_fn *fn;
void *state;
closure_t cl;
struct comm_if ops;
struct cloc loc;
+ uint32_t addr;
uint16_t port;
int fd;
string_t authbind;
struct buffer_if *rbuf;
struct notify_list *notify;
+ bool_t use_proxy;
+ struct sockaddr_in proxy;
};
static int udp_beforepoll(void *state, struct pollfd *fds, int *nfds_io,
- int *timeout_io, const struct timeval *tv,
- uint64_t *now)
+ int *timeout_io)
{
struct udp *st=state;
if (*nfds_io<1) {
return 0;
}
-static void udp_afterpoll(void *state, struct pollfd *fds, int nfds,
- const struct timeval *tv, uint64_t *now)
+static void udp_afterpoll(void *state, struct pollfd *fds, int nfds)
{
struct udp *st=state;
struct sockaddr_in from;
- int fromlen;
+ socklen_t fromlen;
struct notify_list *n;
bool_t done;
int rv;
(struct sockaddr *)&from, &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) {
+ 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);
+ buf_unprepend(st->rbuf,2);
+ memcpy(&from.sin_port,buf_unprepend(st->rbuf,2),2);
+ }
done=False;
for (n=st->notify; n; n=n->next) {
if (n->fn(n->state, st->rbuf, &from)) {
}
if (!done) {
uint32_t source,dest;
- /* XXX manufacture and send NAK packet */
+ /* Manufacture and send NAK packet */
source=get_uint32(st->rbuf->start); /* Us */
dest=get_uint32(st->rbuf->start+4); /* Them */
Message(M_INFO,"udp (port %d): sending NAK\n",st->port);
struct sockaddr_in *dest)
{
struct udp *st=commst;
+ uint8_t *sa;
- /* XXX fix error reporting */
- sendto(st->fd, buf->start, buf->size, 0,
- (struct sockaddr *)dest, sizeof(*dest));
+ if (st->use_proxy) {
+ sa=buf->start-8;
+ memcpy(sa,&dest->sin_addr,4);
+ memset(sa+4,0,4);
+ memcpy(sa+6,&dest->sin_port,2);
+ sendto(st->fd,sa,buf->size+8,0,(struct sockaddr *)&st->proxy,
+ sizeof(st->proxy));
+ } else {
+ sendto(st->fd, buf->start, buf->size, 0,
+ (struct sockaddr *)dest, sizeof(*dest));
+ }
return True;
}
struct udp *st=sst;
struct sockaddr_in addr;
- st->fd=socket(AF_INET, SOCK_DGRAM, 0);
+ st->fd=socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
if (st->fd<0) {
fatal_perror("udp (%s:%d): socket",st->loc.file,st->loc.line);
}
memset(&addr, 0, sizeof(addr));
addr.sin_family=AF_INET;
+ addr.sin_addr.s_addr=htonl(st->addr);
addr.sin_port=htons(st->port);
if (st->authbind) {
pid_t c;
fatal_perror("udp_phase_hook: fork() for authbind");
}
if (c==0) {
- char *argv[4];
+ char *argv[4], addrstr[9], portstr[5];
+ sprintf(addrstr,"%08lX",(long)st->addr);
+ sprintf(portstr,"%04X",st->port);
argv[0]=st->authbind;
- argv[1]="00000000";
- argv[2]=alloca(8);
- if (!argv[2]) exit(ENOMEM);
- sprintf(argv[2],"%04X",htons(st->port));
+ argv[1]=addrstr;
+ argv[2]=portstr;
argv[3]=NULL;
dup2(st->fd,0);
execvp(st->authbind,argv);
- exit(ENOEXEC);
+ _exit(255);
}
- waitpid(c,&status,0);
- if (WEXITSTATUS(status)!=0) {
- errno=WEXITSTATUS(status);
+ while (waitpid(c,&status,0)==-1) {
+ if (errno==EINTR) continue;
fatal_perror("udp (%s:%d): authbind",st->loc.file,st->loc.line);
}
+ if (WIFSIGNALED(status)) {
+ fatal("udp (%s:%d): authbind died on signal %d",st->loc.file,
+ st->loc.line, WTERMSIG(status));
+ }
+ if (WIFEXITED(status) && WEXITSTATUS(status)!=0) {
+ fatal("udp (%s:%d): authbind died with status %d",st->loc.file,
+ st->loc.line, WEXITSTATUS(status));
+ }
} else {
if (bind(st->fd, (struct sockaddr *)&addr, sizeof(addr))!=0) {
fatal_perror("udp (%s:%d): bind",st->loc.file,st->loc.line);
list_t *args)
{
struct udp *st;
- item_t *i;
+ item_t *i,*j;
dict_t *d;
+ list_t *l;
+ uint32_t a;
st=safe_malloc(sizeof(*st),"udp_apply(st)");
st->loc=loc;
st->cl.apply=NULL;
st->cl.interface=&st->ops;
st->ops.st=st;
+ st->ops.min_start_pad=0;
+ st->ops.min_end_pad=0;
st->ops.request_notify=request_notify;
st->ops.release_notify=release_notify;
st->ops.sendmsg=udp_sendmsg;
st->port=0;
+ st->use_proxy=False;
i=list_elem(args,0);
if (!i || i->type!=t_dict) {
}
d=i->data.dict;
+ 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->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;
+ memset(&st->proxy,0,sizeof(st->proxy));
+ st->proxy.sin_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);
+ 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->ops.min_start_pad=8;
+ }
add_hook(PHASE_GETRESOURCES,udp_phase_hook,st);
return new_closure(&st->cl);
}
-init_module udp_module;
void udp_module(dict_t *dict)
{
add_closure(dict,"udp",udp_apply);
~ian / secnet.git / blobdiff