[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 "magic.h"
#include "unaligned.h"
#include "ipaddr.h"
#include "magic.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");
	    buffer_init(st->rbuf,calculate_max_start_pad());
	    rv=recvfrom(st->fd, st->rbuf->start,
			buf_remaining_space(st->rbuf),
			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);
		}
		struct comm_addr ca;
		FILLZERO(ca);
		ca.comm=&st->ops;
		ca.sin=from;
		done=False;
		for (n=st->notify; n; n=n->next) {
		    if (n->fn(n->state, st->rbuf, &ca)) {
			done=True;
			break;
		    }
		}
		if (!done) {
		    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);
	    } 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_prepend(buf,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));
	buf_unprepend(buf,8);
    } 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.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);
    }

    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);
}

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"
dd9209d1	22	#include "magic.h"
794f2398	23	#include "unaligned.h"
ff05a229	24	#include "ipaddr.h"
136740e6	25	#include "magic.h"
2fe58dfd SE	26
	27	static beforepoll_fn udp_beforepoll;
	28	static afterpoll_fn udp_afterpoll;
	29	static comm_request_notify_fn request_notify;
	30	static comm_release_notify_fn release_notify;
	31	static comm_sendmsg_fn udp_sendmsg;
	32
2fe58dfd SE	33	struct notify_list {
	34	comm_notify_fn *fn;
	35	void *state;
	36	struct notify_list *next;
	37	};
	38
	39	struct udp {
	40	closure_t cl;
	41	struct comm_if ops;
	42	struct cloc loc;
3b83c932	43	uint32_t addr;
baa06aeb	44	uint16_t port;
2fe58dfd	45	int fd;
b2a56f7c	46	string_t authbind;
2fe58dfd SE	47	struct buffer_if *rbuf;
2fe58dfd SE	48	struct notify_list *notify;
ff05a229 SE	49	bool_t use_proxy;
ff05a229 SE	50	struct sockaddr_in proxy;
2fe58dfd SE	51	};
2fe58dfd SE	52
5edf478f IJ	53	static const char saddr_to_string(const struct sockaddr_in sin) {
	54	static char bufs[2][100];
	55	static int b;
	56
	57	b ^= 1;
	58	snprintf(bufs[b], sizeof(bufs[b]), "[%s]:%d",
	59	inet_ntoa(sin->sin_addr),
	60	ntohs(sin->sin_port));
	61	return bufs[b];
	62	}
	63
	64	static const char addr_to_string(void commst, const struct comm_addr *ca) {
	65	struct udp *st=commst;
	66	static char sbuf[100];
	67
	68	struct sockaddr_in la;
	69	la.sin_addr.s_addr=htonl(st->addr);
	70	la.sin_port=htons(st->port);
	71
	72	snprintf(sbuf, sizeof(sbuf), "udp:%s-%s",
	73	saddr_to_string(&la), saddr_to_string(&ca->sin));
	74	return sbuf;
	75	}
	76
2fe58dfd	77	static int udp_beforepoll(void state, struct pollfd fds, int *nfds_io,
90a39563	78	int *timeout_io)
2fe58dfd SE	79	{
	80	struct udp *st=state;
	81	if (*nfds_io<1) {
	82	*nfds_io=1;
	83	return ERANGE;
	84	}
	85	*nfds_io=1;
	86	fds->fd=st->fd;
	87	fds->events=POLLIN;
	88	return 0;
	89	}
	90
90a39563	91	static void udp_afterpoll(void state, struct pollfd fds, int nfds)
2fe58dfd SE	92	{
	93	struct udp *st=state;
	94	struct sockaddr_in from;
b1a0f651	95	socklen_t fromlen;
2fe58dfd SE	96	struct notify_list *n;
	97	bool_t done;
	98	int rv;
	99
	100	if (nfds && (fds->revents & POLLIN)) {
	101	do {
a15faeb2	102	FILLZERO(from);
2fe58dfd SE	103	fromlen=sizeof(from);
	104	BUF_ASSERT_FREE(st->rbuf);
	105	BUF_ALLOC(st->rbuf,"udp_afterpoll");
6af9a984	106	buffer_init(st->rbuf,calculate_max_start_pad());
1b4ca45e	107	rv=recvfrom(st->fd, st->rbuf->start,
92795040	108	buf_remaining_space(st->rbuf),
1b4ca45e	109	0, (struct sockaddr *)&from, &fromlen);
2fe58dfd SE	110	if (rv>0) {
2fe58dfd SE	111	st->rbuf->size=rv;
ff05a229 SE	112	if (st->use_proxy) {
	113	/* Check that the packet came from our poxy server;
	114	we shouldn't be contacted directly by anybody else
	115	(since they can trivially forge source addresses) */
	116	if (memcmp(&from.sin_addr,&st->proxy.sin_addr,4)!=0 \|\|
	117	memcmp(&from.sin_port,&st->proxy.sin_port,2)!=0) {
	118	Message(M_INFO,"udp: received packet that's not "
	119	"from the proxy\n");
	120	BUF_FREE(st->rbuf);
	121	continue;
	122	}
	123	memcpy(&from.sin_addr,buf_unprepend(st->rbuf,4),4);
	124	buf_unprepend(st->rbuf,2);
	125	memcpy(&from.sin_port,buf_unprepend(st->rbuf,2),2);
	126	}
8534d602 IJ	127	struct comm_addr ca;
	128	FILLZERO(ca);
	129	ca.comm=&st->ops;
	130	ca.sin=from;
2fe58dfd SE	131	done=False;
2fe58dfd SE	132	for (n=st->notify; n; n=n->next) {
a15faeb2	133	if (n->fn(n->state, st->rbuf, &ca)) {
2fe58dfd SE	134	done=True;
	135	break;
	136	}
	137	}
	138	if (!done) {
bf28fc73 IJ	139	uint32_t msgtype;
	140	if (st->rbuf->size>12 /* prevents traffic amplification */
	141	&& ((msgtype=get_uint32(st->rbuf->start+8))
	142	!= LABEL_NAK)) {
	143	uint32_t source,dest;
	144	/* Manufacture and send NAK packet */
	145	source=get_uint32(st->rbuf->start); /* Us */
	146	dest=get_uint32(st->rbuf->start+4); /* Them */
8534d602	147	send_nak(&ca,source,dest,msgtype,st->rbuf,"unwanted");
bf28fc73	148	}
2fe58dfd SE	149	BUF_FREE(st->rbuf);
	150	}
	151	BUF_ASSERT_FREE(st->rbuf);
	152	} else {
	153	BUF_FREE(st->rbuf);
	154	}
	155	} while (rv>=0);
	156	}
	157	}
	158
	159	static void request_notify(void commst, void nst, comm_notify_fn *fn)
	160	{
	161	struct udp *st=commst;
	162	struct notify_list *n;
	163
	164	n=safe_malloc(sizeof(*n),"request_notify");
	165	n->fn=fn;
	166	n->state=nst;
	167	n->next=st->notify;
	168	st->notify=n;
	169	}
	170
	171	static void release_notify(void commst, void nst, comm_notify_fn *fn)
	172	{
	173	struct udp *st=commst;
	174	struct notify_list n, p, t;
	175
	176	/* XXX untested */
	177	p=&st->notify;
	178	for (n=st->notify; n; )
	179	{
	180	if (n->state==nst && n->fn==fn) {
	181	t=n;
	182	*p=n->next;
	183	n=n->next;
	184	free(t);
	185	} else {
	186	p=&n->next;
	187	n=n->next;
	188	}
	189	}
	190	}
	191
	192	static bool_t udp_sendmsg(void commst, struct buffer_if buf,
a15faeb2	193	const struct comm_addr *dest)
2fe58dfd SE	194	{
2fe58dfd SE	195	struct udp *st=commst;
ff05a229	196	uint8_t *sa;
2fe58dfd	197
ff05a229	198	if (st->use_proxy) {
3abd18e8	199	sa=buf_prepend(buf,8);
a15faeb2	200	memcpy(sa,&dest->sin.sin_addr,4);
ff05a229	201	memset(sa+4,0,4);
a15faeb2	202	memcpy(sa+6,&dest->sin.sin_port,2);
ff05a229 SE	203	sendto(st->fd,sa,buf->size+8,0,(struct sockaddr *)&st->proxy,
ff05a229 SE	204	sizeof(st->proxy));
3abd18e8	205	buf_unprepend(buf,8);
ff05a229 SE	206	} else {
ff05a229 SE	207	sendto(st->fd, buf->start, buf->size, 0,
a15faeb2	208	(struct sockaddr *)&dest->sin, sizeof(dest->sin));
ff05a229	209	}
2fe58dfd SE	210
	211	return True;
	212	}
	213
baa06aeb SE	214	static void udp_phase_hook(void *sst, uint32_t new_phase)
	215	{
	216	struct udp *st=sst;
	217	struct sockaddr_in addr;
	218
3b83c932	219	st->fd=socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
baa06aeb SE	220	if (st->fd<0) {
	221	fatal_perror("udp (%s:%d): socket",st->loc.file,st->loc.line);
	222	}
	223	if (fcntl(st->fd, F_SETFL, fcntl(st->fd, F_GETFL)\|O_NONBLOCK)==-1) {
	224	fatal_perror("udp (%s:%d): fcntl(set O_NONBLOCK)",
	225	st->loc.file,st->loc.line);
	226	}
	227	if (fcntl(st->fd, F_SETFD, FD_CLOEXEC)==-1) {
	228	fatal_perror("udp (%s:%d): fcntl(set FD_CLOEXEC)",
	229	st->loc.file,st->loc.line);
	230	}
	231
076bb54e	232	FILLZERO(addr);
baa06aeb	233	addr.sin_family=AF_INET;
3b83c932	234	addr.sin_addr.s_addr=htonl(st->addr);
baa06aeb	235	addr.sin_port=htons(st->port);
b2a56f7c SE	236	if (st->authbind) {
	237	pid_t c;
	238	int status;
	239
	240	/* XXX this fork() and waitpid() business needs to be hidden
	241	in some system-specific library functions. */
	242	c=fork();
	243	if (c==-1) {
	244	fatal_perror("udp_phase_hook: fork() for authbind");
	245	}
	246	if (c==0) {
3b83c932	247	char *argv[4], addrstr[9], portstr[5];
51b25953 IJ	248	sprintf(addrstr,"%08lX",(long)addr.sin_addr.s_addr);
51b25953 IJ	249	sprintf(portstr,"%04X",addr.sin_port);
b2a56f7c	250	argv[0]=st->authbind;
3b83c932 SE	251	argv[1]=addrstr;
3b83c932 SE	252	argv[2]=portstr;
b2a56f7c SE	253	argv[3]=NULL;
	254	dup2(st->fd,0);
	255	execvp(st->authbind,argv);
3b83c932	256	_exit(255);
b2a56f7c	257	}
3b83c932 SE	258	while (waitpid(c,&status,0)==-1) {
3b83c932 SE	259	if (errno==EINTR) continue;
b2a56f7c SE	260	fatal_perror("udp (%s:%d): authbind",st->loc.file,st->loc.line);
b2a56f7c SE	261	}
3b83c932 SE	262	if (WIFSIGNALED(status)) {
	263	fatal("udp (%s:%d): authbind died on signal %d",st->loc.file,
	264	st->loc.line, WTERMSIG(status));
	265	}
	266	if (WIFEXITED(status) && WEXITSTATUS(status)!=0) {
	267	fatal("udp (%s:%d): authbind died with status %d",st->loc.file,
	268	st->loc.line, WEXITSTATUS(status));
	269	}
b2a56f7c SE	270	} else {
	271	if (bind(st->fd, (struct sockaddr *)&addr, sizeof(addr))!=0) {
	272	fatal_perror("udp (%s:%d): bind",st->loc.file,st->loc.line);
	273	}
baa06aeb SE	274	}
	275
	276	register_for_poll(st,udp_beforepoll,udp_afterpoll,1,"udp");
	277	}
	278
2fe58dfd SE	279	static list_t udp_apply(closure_t self, struct cloc loc, dict_t *context,
	280	list_t *args)
	281	{
	282	struct udp *st;
3b83c932	283	item_t i,j;
2fe58dfd	284	dict_t *d;
ff05a229 SE	285	list_t *l;
ff05a229 SE	286	uint32_t a;
2fe58dfd SE	287
	288	st=safe_malloc(sizeof(*st),"udp_apply(st)");
	289	st->loc=loc;
	290	st->cl.description="udp";
	291	st->cl.type=CL_COMM;
	292	st->cl.apply=NULL;
	293	st->cl.interface=&st->ops;
	294	st->ops.st=st;
	295	st->ops.request_notify=request_notify;
	296	st->ops.release_notify=release_notify;
	297	st->ops.sendmsg=udp_sendmsg;
5edf478f	298	st->ops.addr_to_string=addr_to_string;
baa06aeb	299	st->port=0;
ff05a229	300	st->use_proxy=False;
2fe58dfd SE	301
	302	i=list_elem(args,0);
	303	if (!i \|\| i->type!=t_dict) {
	304	cfgfatal(st->loc,"udp","first argument must be a dictionary\n");
	305	}
	306	d=i->data.dict;
	307
3b83c932	308	j=dict_find_item(d,"address",False,"udp",st->loc);
44128667	309	st->addr=j?string_item_to_ipaddr(j, "udp"):INADDR_ANY;
baa06aeb	310	st->port=dict_read_number(d,"port",True,"udp",st->loc,0);
2fe58dfd	311	st->rbuf=find_cl_if(d,"buffer",CL_BUFFER,True,"udp",st->loc);
b2a56f7c	312	st->authbind=dict_read_string(d,"authbind",False,"udp",st->loc);
ff05a229 SE	313	l=dict_lookup(d,"proxy");
	314	if (l) {
	315	st->use_proxy=True;
076bb54e	316	FILLZERO(st->proxy);
ff05a229 SE	317	st->proxy.sin_family=AF_INET;
	318	i=list_elem(l,0);
	319	if (!i \|\| i->type!=t_string) {
	320	cfgfatal(st->loc,"udp","proxy must supply ""addr"",port\n");
	321	}
	322	a=string_item_to_ipaddr(i,"proxy");
	323	st->proxy.sin_addr.s_addr=htonl(a);
	324	i=list_elem(l,1);
	325	if (!i \|\| i->type!=t_number) {
	326	cfgfatal(st->loc,"udp","proxy must supply ""addr"",port\n");
	327	}
	328	st->proxy.sin_port=htons(i->data.number);
ff05a229	329	}
2fe58dfd	330
3abd18e8 IJ	331	update_max_start_pad(&comm_max_start_pad, st->use_proxy ? 8 : 0);
3abd18e8 IJ	332
baa06aeb	333	add_hook(PHASE_GETRESOURCES,udp_phase_hook,st);
2fe58dfd SE	334
	335	return new_closure(&st->cl);
	336	}
	337
2fe58dfd SE	338	void udp_module(dict_t *dict)
	339	{
	340	add_closure(dict,"udp",udp_apply);
	341	}