[secnet] / udp.c

/* UDP send/receive module for secnet */

/* This module enables sites to communicate by sending UDP
 * packets. When an instance of the module is created we can
 * optionally bind to a particular local IP address (not implemented
 * yet).
 *
 * Packets are offered to registered receivers in turn. Once one
 * accepts it, it isn't offered to any more. */

#include "secnet.h"
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include "util.h"
#include "unaligned.h"
#include "ipaddr.h"

static beforepoll_fn udp_beforepoll;
static afterpoll_fn udp_afterpoll;
static comm_request_notify_fn request_notify;
static comm_release_notify_fn release_notify;
static comm_sendmsg_fn udp_sendmsg;

struct notify_list {
    comm_notify_fn *fn;
    void *state;
    struct notify_list *next;
};

struct udp {
    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 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));
    return sbuf;
}

static int udp_beforepoll(void *state, struct pollfd *fds, int *nfds_io,
			  int *timeout_io)
{
    struct udp *st=state;
    if (*nfds_io<1) {
	*nfds_io=1;
	return ERANGE;
    }
    *nfds_io=1;
    fds->fd=st->fd;
    fds->events=POLLIN;
    return 0;
}

static void udp_afterpoll(void *state, struct pollfd *fds, int nfds)
{
    struct udp *st=state;
    struct sockaddr_in from;
    socklen_t fromlen;
    struct notify_list *n;
    bool_t done;
    int rv;

    if (nfds && (fds->revents & POLLIN)) {
	do {
	    FILLZERO(from);
	    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);
	    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) {
		    struct comm_addr ca;
		    FILLZERO(ca);
		    ca.comm=&st->ops;
		    ca.sin=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));
		    BUF_FREE(st->rbuf);
		}
		BUF_ASSERT_FREE(st->rbuf);
	    } else {
		BUF_FREE(st->rbuf);
	    }
	} while (rv>=0);
    }
}

static void request_notify(void *commst, void *nst, comm_notify_fn *fn)
{
    struct udp *st=commst;
    struct notify_list *n;
    
    n=safe_malloc(sizeof(*n),"request_notify");
    n->fn=fn;
    n->state=nst;
    n->next=st->notify;
    st->notify=n;
}

static void release_notify(void *commst, void *nst, comm_notify_fn *fn)
{
    struct udp *st=commst;
    struct notify_list *n, **p, *t;

    /* XXX untested */
    p=&st->notify;
    for (n=st->notify; n; )
    {
	if (n->state==nst && n->fn==fn) {
	    t=n;
	    *p=n->next;
	    n=n->next;
	    free(t);
	} else {
	    p=&n->next;
	    n=n->next;
	}
    }
}

static bool_t udp_sendmsg(void *commst, struct buffer_if *buf,
			  const struct comm_addr *dest)
{
    struct udp *st=commst;
    uint8_t *sa;

    if (st->use_proxy) {
	sa=buf->start-8;
	memcpy(sa,&dest->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));
    } else {
	sendto(st->fd, buf->start, buf->size, 0,
	       (struct sockaddr *)&dest->sin, sizeof(dest->sin));
    }

    return True;
}

static void udp_phase_hook(void *sst, uint32_t new_phase)
{
    struct udp *st=sst;
    struct sockaddr_in addr;

    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);
    }
    if (fcntl(st->fd, F_SETFL, fcntl(st->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);
    }

    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;

	/* XXX this fork() and waitpid() business needs to be hidden
	   in some system-specific library functions. */
	c=fork();
	if (c==-1) {
	    fatal_perror("udp_phase_hook: fork() for authbind");
	}
	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);
	    argv[0]=st->authbind;
	    argv[1]=addrstr;
	    argv[2]=portstr;
	    argv[3]=NULL;
	    dup2(st->fd,0);
	    execvp(st->authbind,argv);
	    _exit(255);
	}
	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);
	}
    }

    register_for_poll(st,udp_beforepoll,udp_afterpoll,1,"udp");
}

static list_t *udp_apply(closure_t *self, struct cloc loc, dict_t *context,
			 list_t *args)
{
    struct udp *st;
    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.description="udp";
    st->cl.type=CL_COMM;
    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->ops.addr_to_string=addr_to_string;
    st->port=0;
    st->use_proxy=False;

    i=list_elem(args,0);
    if (!i || i->type!=t_dict) {
	cfgfatal(st->loc,"udp","first argument must be a dictionary\n");
    }
    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;
	FILLZERO(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);
}

void udp_module(dict_t *dict)
{
    add_closure(dict,"udp",udp_apply);
}
Commit	Line	Data
2fe58dfd SE	1	/* UDP send/receive module for secnet */
	2
	3	/* This module enables sites to communicate by sending UDP
	4	* packets. When an instance of the module is created we can
	5	* optionally bind to a particular local IP address (not implemented
	6	* yet).
	7	*
2fe58dfd SE	8	* Packets are offered to registered receivers in turn. Once one
	9	* accepts it, it isn't offered to any more. */
	10
8689b3a9	11	#include "secnet.h"
2fe58dfd SE	12	#include <stdio.h>
	13	#include <unistd.h>
	14	#include <fcntl.h>
	15	#include <string.h>
	16	#include <errno.h>
2fe58dfd	17	#include <sys/socket.h>
b2a56f7c	18	#include <sys/wait.h>
5edf478f IJ	19	#include <netinet/in.h>
5edf478f IJ	20	#include <arpa/inet.h>
2fe58dfd	21	#include "util.h"
794f2398	22	#include "unaligned.h"
ff05a229	23	#include "ipaddr.h"
2fe58dfd SE	24
	25	static beforepoll_fn udp_beforepoll;
	26	static afterpoll_fn udp_afterpoll;
	27	static comm_request_notify_fn request_notify;
	28	static comm_release_notify_fn release_notify;
	29	static comm_sendmsg_fn udp_sendmsg;
	30
2fe58dfd SE	31	struct notify_list {
	32	comm_notify_fn *fn;
	33	void *state;
	34	struct notify_list *next;
	35	};
	36
	37	struct udp {
	38	closure_t cl;
	39	struct comm_if ops;
	40	struct cloc loc;
3b83c932	41	uint32_t addr;
baa06aeb	42	uint16_t port;
2fe58dfd	43	int fd;
b2a56f7c	44	string_t authbind;
2fe58dfd SE	45	struct buffer_if *rbuf;
2fe58dfd SE	46	struct notify_list *notify;
ff05a229 SE	47	bool_t use_proxy;
ff05a229 SE	48	struct sockaddr_in proxy;
2fe58dfd SE	49	};
2fe58dfd SE	50
5edf478f IJ	51	static const char saddr_to_string(const struct sockaddr_in sin) {
	52	static char bufs[2][100];
	53	static int b;
	54
	55	b ^= 1;
	56	snprintf(bufs[b], sizeof(bufs[b]), "[%s]:%d",
	57	inet_ntoa(sin->sin_addr),
	58	ntohs(sin->sin_port));
	59	return bufs[b];
	60	}
	61
	62	static const char addr_to_string(void commst, const struct comm_addr *ca) {
	63	struct udp *st=commst;
	64	static char sbuf[100];
	65
	66	struct sockaddr_in la;
	67	la.sin_addr.s_addr=htonl(st->addr);
	68	la.sin_port=htons(st->port);
	69
	70	snprintf(sbuf, sizeof(sbuf), "udp:%s-%s",
	71	saddr_to_string(&la), saddr_to_string(&ca->sin));
	72	return sbuf;
	73	}
	74
2fe58dfd	75	static int udp_beforepoll(void state, struct pollfd fds, int *nfds_io,
90a39563	76	int *timeout_io)
2fe58dfd SE	77	{
	78	struct udp *st=state;
	79	if (*nfds_io<1) {
	80	*nfds_io=1;
	81	return ERANGE;
	82	}
	83	*nfds_io=1;
	84	fds->fd=st->fd;
	85	fds->events=POLLIN;
	86	return 0;
	87	}
	88
90a39563	89	static void udp_afterpoll(void state, struct pollfd fds, int nfds)
2fe58dfd SE	90	{
	91	struct udp *st=state;
	92	struct sockaddr_in from;
b1a0f651	93	socklen_t fromlen;
2fe58dfd SE	94	struct notify_list *n;
	95	bool_t done;
	96	int rv;
	97
	98	if (nfds && (fds->revents & POLLIN)) {
	99	do {
a15faeb2	100	FILLZERO(from);
2fe58dfd SE	101	fromlen=sizeof(from);
	102	BUF_ASSERT_FREE(st->rbuf);
	103	BUF_ALLOC(st->rbuf,"udp_afterpoll");
	104	rv=recvfrom(st->fd, st->rbuf->start, st->rbuf->len, 0,
	105	(struct sockaddr *)&from, &fromlen);
	106	if (rv>0) {
	107	st->rbuf->size=rv;
ff05a229 SE	108	if (st->use_proxy) {
	109	/* Check that the packet came from our poxy server;
	110	we shouldn't be contacted directly by anybody else
	111	(since they can trivially forge source addresses) */
	112	if (memcmp(&from.sin_addr,&st->proxy.sin_addr,4)!=0 \|\|
	113	memcmp(&from.sin_port,&st->proxy.sin_port,2)!=0) {
	114	Message(M_INFO,"udp: received packet that's not "
	115	"from the proxy\n");
	116	BUF_FREE(st->rbuf);
	117	continue;
	118	}
	119	memcpy(&from.sin_addr,buf_unprepend(st->rbuf,4),4);
	120	buf_unprepend(st->rbuf,2);
	121	memcpy(&from.sin_port,buf_unprepend(st->rbuf,2),2);
	122	}
2fe58dfd SE	123	done=False;
2fe58dfd SE	124	for (n=st->notify; n; n=n->next) {
a15faeb2 IJ	125	struct comm_addr ca;
	126	FILLZERO(ca);
	127	ca.comm=&st->ops;
	128	ca.sin=from;
	129	if (n->fn(n->state, st->rbuf, &ca)) {
2fe58dfd SE	130	done=True;
	131	break;
	132	}
	133	}
	134	if (!done) {
794f2398	135	uint32_t source,dest;
ff05a229	136	/* Manufacture and send NAK packet */
794f2398 SE	137	source=get_uint32(st->rbuf->start); /* Us */
	138	dest=get_uint32(st->rbuf->start+4); /* Them */
	139	Message(M_INFO,"udp (port %d): sending NAK\n",st->port);
	140	buffer_init(st->rbuf,0);
	141	buf_append_uint32(st->rbuf,dest);
	142	buf_append_uint32(st->rbuf,source);
	143	buf_append_uint32(st->rbuf,0); /* NAK is msg type 0 */
	144	sendto(st->fd, st->rbuf->start, st->rbuf->size, 0,
	145	(struct sockaddr *)&from, sizeof(from));
2fe58dfd SE	146	BUF_FREE(st->rbuf);
	147	}
	148	BUF_ASSERT_FREE(st->rbuf);
	149	} else {
	150	BUF_FREE(st->rbuf);
	151	}
	152	} while (rv>=0);
	153	}
	154	}
	155
	156	static void request_notify(void commst, void nst, comm_notify_fn *fn)
	157	{
	158	struct udp *st=commst;
	159	struct notify_list *n;
	160
	161	n=safe_malloc(sizeof(*n),"request_notify");
	162	n->fn=fn;
	163	n->state=nst;
	164	n->next=st->notify;
	165	st->notify=n;
	166	}
	167
	168	static void release_notify(void commst, void nst, comm_notify_fn *fn)
	169	{
	170	struct udp *st=commst;
	171	struct notify_list n, p, t;
	172
	173	/* XXX untested */
	174	p=&st->notify;
	175	for (n=st->notify; n; )
	176	{
	177	if (n->state==nst && n->fn==fn) {
	178	t=n;
	179	*p=n->next;
	180	n=n->next;
	181	free(t);
	182	} else {
	183	p=&n->next;
	184	n=n->next;
	185	}
	186	}
	187	}
	188
	189	static bool_t udp_sendmsg(void commst, struct buffer_if buf,
a15faeb2	190	const struct comm_addr *dest)
2fe58dfd SE	191	{
2fe58dfd SE	192	struct udp *st=commst;
ff05a229	193	uint8_t *sa;
2fe58dfd	194
ff05a229 SE	195	if (st->use_proxy) {
ff05a229 SE	196	sa=buf->start-8;
a15faeb2	197	memcpy(sa,&dest->sin.sin_addr,4);
ff05a229	198	memset(sa+4,0,4);
a15faeb2	199	memcpy(sa+6,&dest->sin.sin_port,2);
ff05a229 SE	200	sendto(st->fd,sa,buf->size+8,0,(struct sockaddr *)&st->proxy,
	201	sizeof(st->proxy));
	202	} else {
	203	sendto(st->fd, buf->start, buf->size, 0,
a15faeb2	204	(struct sockaddr *)&dest->sin, sizeof(dest->sin));
ff05a229	205	}
2fe58dfd SE	206
	207	return True;
	208	}
	209
baa06aeb SE	210	static void udp_phase_hook(void *sst, uint32_t new_phase)
	211	{
	212	struct udp *st=sst;
	213	struct sockaddr_in addr;
	214
3b83c932	215	st->fd=socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
baa06aeb SE	216	if (st->fd<0) {
	217	fatal_perror("udp (%s:%d): socket",st->loc.file,st->loc.line);
	218	}
	219	if (fcntl(st->fd, F_SETFL, fcntl(st->fd, F_GETFL)\|O_NONBLOCK)==-1) {
	220	fatal_perror("udp (%s:%d): fcntl(set O_NONBLOCK)",
	221	st->loc.file,st->loc.line);
	222	}
	223	if (fcntl(st->fd, F_SETFD, FD_CLOEXEC)==-1) {
	224	fatal_perror("udp (%s:%d): fcntl(set FD_CLOEXEC)",
	225	st->loc.file,st->loc.line);
	226	}
	227
076bb54e	228	FILLZERO(addr);
baa06aeb	229	addr.sin_family=AF_INET;
3b83c932	230	addr.sin_addr.s_addr=htonl(st->addr);
baa06aeb	231	addr.sin_port=htons(st->port);
b2a56f7c SE	232	if (st->authbind) {
	233	pid_t c;
	234	int status;
	235
	236	/* XXX this fork() and waitpid() business needs to be hidden
	237	in some system-specific library functions. */
	238	c=fork();
	239	if (c==-1) {
	240	fatal_perror("udp_phase_hook: fork() for authbind");
	241	}
	242	if (c==0) {
3b83c932	243	char *argv[4], addrstr[9], portstr[5];
51b25953 IJ	244	sprintf(addrstr,"%08lX",(long)addr.sin_addr.s_addr);
51b25953 IJ	245	sprintf(portstr,"%04X",addr.sin_port);
b2a56f7c	246	argv[0]=st->authbind;
3b83c932 SE	247	argv[1]=addrstr;
3b83c932 SE	248	argv[2]=portstr;
b2a56f7c SE	249	argv[3]=NULL;
	250	dup2(st->fd,0);
	251	execvp(st->authbind,argv);
3b83c932	252	_exit(255);
b2a56f7c	253	}
3b83c932 SE	254	while (waitpid(c,&status,0)==-1) {
3b83c932 SE	255	if (errno==EINTR) continue;
b2a56f7c SE	256	fatal_perror("udp (%s:%d): authbind",st->loc.file,st->loc.line);
b2a56f7c SE	257	}
3b83c932 SE	258	if (WIFSIGNALED(status)) {
	259	fatal("udp (%s:%d): authbind died on signal %d",st->loc.file,
	260	st->loc.line, WTERMSIG(status));
	261	}
	262	if (WIFEXITED(status) && WEXITSTATUS(status)!=0) {
	263	fatal("udp (%s:%d): authbind died with status %d",st->loc.file,
	264	st->loc.line, WEXITSTATUS(status));
	265	}
b2a56f7c SE	266	} else {
	267	if (bind(st->fd, (struct sockaddr *)&addr, sizeof(addr))!=0) {
	268	fatal_perror("udp (%s:%d): bind",st->loc.file,st->loc.line);
	269	}
baa06aeb SE	270	}
	271
	272	register_for_poll(st,udp_beforepoll,udp_afterpoll,1,"udp");
	273	}
	274
2fe58dfd SE	275	static list_t udp_apply(closure_t self, struct cloc loc, dict_t *context,
	276	list_t *args)
	277	{
	278	struct udp *st;
3b83c932	279	item_t i,j;
2fe58dfd	280	dict_t *d;
ff05a229 SE	281	list_t *l;
ff05a229 SE	282	uint32_t a;
2fe58dfd SE	283
	284	st=safe_malloc(sizeof(*st),"udp_apply(st)");
	285	st->loc=loc;
	286	st->cl.description="udp";
	287	st->cl.type=CL_COMM;
	288	st->cl.apply=NULL;
	289	st->cl.interface=&st->ops;
	290	st->ops.st=st;
ff05a229 SE	291	st->ops.min_start_pad=0;
ff05a229 SE	292	st->ops.min_end_pad=0;
2fe58dfd SE	293	st->ops.request_notify=request_notify;
	294	st->ops.release_notify=release_notify;
	295	st->ops.sendmsg=udp_sendmsg;
5edf478f	296	st->ops.addr_to_string=addr_to_string;
baa06aeb	297	st->port=0;
ff05a229	298	st->use_proxy=False;
2fe58dfd SE	299
	300	i=list_elem(args,0);
	301	if (!i \|\| i->type!=t_dict) {
	302	cfgfatal(st->loc,"udp","first argument must be a dictionary\n");
	303	}
	304	d=i->data.dict;
	305
3b83c932	306	j=dict_find_item(d,"address",False,"udp",st->loc);
44128667	307	st->addr=j?string_item_to_ipaddr(j, "udp"):INADDR_ANY;
baa06aeb	308	st->port=dict_read_number(d,"port",True,"udp",st->loc,0);
2fe58dfd	309	st->rbuf=find_cl_if(d,"buffer",CL_BUFFER,True,"udp",st->loc);
b2a56f7c	310	st->authbind=dict_read_string(d,"authbind",False,"udp",st->loc);
ff05a229 SE	311	l=dict_lookup(d,"proxy");
	312	if (l) {
	313	st->use_proxy=True;
076bb54e	314	FILLZERO(st->proxy);
ff05a229 SE	315	st->proxy.sin_family=AF_INET;
	316	i=list_elem(l,0);
	317	if (!i \|\| i->type!=t_string) {
	318	cfgfatal(st->loc,"udp","proxy must supply ""addr"",port\n");
	319	}
	320	a=string_item_to_ipaddr(i,"proxy");
	321	st->proxy.sin_addr.s_addr=htonl(a);
	322	i=list_elem(l,1);
	323	if (!i \|\| i->type!=t_number) {
	324	cfgfatal(st->loc,"udp","proxy must supply ""addr"",port\n");
	325	}
	326	st->proxy.sin_port=htons(i->data.number);
	327	st->ops.min_start_pad=8;
	328	}
2fe58dfd	329
baa06aeb	330	add_hook(PHASE_GETRESOURCES,udp_phase_hook,st);
2fe58dfd SE	331
	332	return new_closure(&st->cl);
	333	}
	334
2fe58dfd SE	335	void udp_module(dict_t *dict)
	336	{
	337	add_closure(dict,"udp",udp_apply);
	338	}