#include <errno.h>
#include <sys/socket.h>
#include <sys/wait.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
#include "util.h"
+#include "magic.h"
#include "unaligned.h"
#include "ipaddr.h"
+#include "magic.h"
static beforepoll_fn udp_beforepoll;
static afterpoll_fn udp_afterpoll;
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 *addr_to_string(void *commst, const struct comm_addr *ca) {
+ struct udp *st=commst;
+ static char sbuf[100];
+
+ snprintf(sbuf, sizeof(sbuf), "udp:%s-%s",
+ iaddr_to_string(&st->addr), iaddr_to_string(&ca->ia));
+ return sbuf;
+}
+
static int udp_beforepoll(void *state, struct pollfd *fds, int *nfds_io,
int *timeout_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;
fromlen=sizeof(from);
BUF_ASSERT_FREE(st->rbuf);
BUF_ALLOC(st->rbuf,"udp_afterpoll");
- rv=recvfrom(st->fd, st->rbuf->start, st->rbuf->len, 0,
- (struct sockaddr *)&from, &fromlen);
+ buffer_init(st->rbuf,calculate_max_start_pad());
+ 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;
+ ca.comm=&st->ops;
+ ca.ia=from;
done=False;
for (n=st->notify; n; n=n->next) {
- if (n->fn(n->state, st->rbuf, &from)) {
+ if (n->fn(n->state, st->rbuf, &ca)) {
done=True;
break;
}
}
if (!done) {
- uint32_t source,dest;
- /* 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);
- buffer_init(st->rbuf,0);
- buf_append_uint32(st->rbuf,dest);
- buf_append_uint32(st->rbuf,source);
- buf_append_uint32(st->rbuf,0); /* NAK is msg type 0 */
- sendto(st->fd, st->rbuf->start, st->rbuf->size, 0,
- (struct sockaddr *)&from, sizeof(from));
+ uint32_t msgtype;
+ if (st->rbuf->size>12 /* prevents traffic amplification */
+ && ((msgtype=get_uint32(st->rbuf->start+8))
+ != LABEL_NAK)) {
+ uint32_t source,dest;
+ /* Manufacture and send NAK packet */
+ source=get_uint32(st->rbuf->start); /* Us */
+ dest=get_uint32(st->rbuf->start+4); /* Them */
+ send_nak(&ca,source,dest,msgtype,st->rbuf,"unwanted");
+ }
BUF_FREE(st->rbuf);
}
BUF_ASSERT_FREE(st->rbuf);
}
static bool_t udp_sendmsg(void *commst, struct buffer_if *buf,
- struct sockaddr_in *dest)
+ const struct comm_addr *dest)
{
struct udp *st=commst;
uint8_t *sa;
if (st->use_proxy) {
- sa=buf->start-8;
- memcpy(sa,&dest->sin_addr,4);
+ sa=buf_prepend(buf,8);
+ 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_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, sizeof(*dest));
+ &dest->ia.sa, iaddr_socklen(&dest->ia));
}
return True;
}
-static void udp_phase_hook(void *sst, uint32_t new_phase)
+static void udp_make_socket(struct udp *st, struct udp *us)
{
- struct udp *st=sst;
- struct sockaddr_in addr;
-
- st->fd=socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
- if (st->fd<0) {
+ const union iaddr *addr=&us->addr;
+ us->fd=socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
+ if (us->fd<0) {
fatal_perror("udp (%s:%d): socket",st->loc.file,st->loc.line);
}
- if (fcntl(st->fd, F_SETFL, fcntl(st->fd, F_GETFL)|O_NONBLOCK)==-1) {
+ if (fcntl(us->fd, F_SETFL, fcntl(us->fd, F_GETFL)|O_NONBLOCK)==-1) {
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(us->fd);
- FILLZERO(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;
int status;
}
if (c==0) {
char *argv[4], addrstr[9], portstr[5];
- sprintf(addrstr,"%08lX",(long)st->addr);
- sprintf(portstr,"%04X",st->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;
argv[3]=NULL;
- dup2(st->fd,0);
+ dup2(us->fd,0);
execvp(st->authbind,argv);
_exit(255);
}
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);
}
}
+}
+static void udp_phase_hook(void *sst, uint32_t new_phase)
+{
+ struct udp *st=sst;
+ udp_make_socket(st,st);
register_for_poll(st,udp_beforepoll,udp_afterpoll,1,"udp");
}
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->ops.addr_to_string=addr_to_string;
st->use_proxy=False;
i=list_elem(args,0);
}
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->ops.min_start_pad=8;
+ st->proxy.sin.sin_port=htons(i->data.number);
}
+ update_max_start_pad(&comm_max_start_pad, st->use_proxy ? 8 : 0);
+
add_hook(PHASE_GETRESOURCES,udp_phase_hook,st);
return new_closure(&st->cl);
~ian / secnet.git / blobdiff