[secnet] / slip.c

/* When dealing with SLIP (to a pty, or ipif) we have separate rx, tx
   and client buffers.  When receiving we may read() any amount, not
   just whole packets.  When transmitting we need to bytestuff anyway,
   and may be part-way through receiving. */

#include "secnet.h"
#include "util.h"
#include "netlink.h"
#include "process.h"
#include "unaligned.h"
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>

#define SLIP_END    192
#define SLIP_ESC    219
#define SLIP_ESCEND 220
#define SLIP_ESCESC 221

struct slip {
    struct netlink nl;
    struct buffer_if *buff; /* We unstuff received packets into here
			       and send them to the netlink code. */
    bool_t pending_esc;
    bool_t ignoring_packet; /* If this packet was corrupt or overlong,
			       we ignore everything up to the next END */
    netlink_deliver_fn *netlink_to_tunnel;
};

/* Generic SLIP mangling code */

static void slip_stuff(struct slip *st, struct buffer_if *buf, int fd)
{
    uint8_t txbuf[DEFAULT_BUFSIZE];
    uint8_t *i;
    int32_t j=0;

    BUF_ASSERT_USED(buf);

    /* There's probably a much more efficient way of implementing this */
    txbuf[j++]=SLIP_END;
    for (i=buf->start; i<(buf->start+buf->size); i++) {
	switch (*i) {
	case SLIP_END:
	    txbuf[j++]=SLIP_ESC;
	    txbuf[j++]=SLIP_ESCEND;
	    break;
	case SLIP_ESC:
	    txbuf[j++]=SLIP_ESC;
	    txbuf[j++]=SLIP_ESCESC;
	    break;
	default:
	    txbuf[j++]=*i;
	    break;
	}
	if ((j+2)>DEFAULT_BUFSIZE) {
	    if (write(fd,txbuf,j)<0) {
		fatal_perror("slip_stuff: write()");
	    }
	    j=0;
	}
    }
    txbuf[j++]=SLIP_END;
    if (write(fd,txbuf,j)<0) {
	fatal_perror("slip_stuff: write()");
    }
    BUF_FREE(buf);
}

static void slip_unstuff(struct slip *st, uint8_t *buf, uint32_t l)
{
    uint32_t i;

    BUF_ASSERT_USED(st->buff);
    for (i=0; i<l; i++) {
	int outputchr;
	enum { OUTPUT_END = 256, OUTPUT_NOTHING = 257 };

	if (!st->buff->size)
	    buffer_init(st->buff,calculate_max_start_pad());

	if (st->pending_esc) {
	    st->pending_esc=False;
	    switch(buf[i]) {
	    case SLIP_ESCEND:
		outputchr=SLIP_END;
		break;
	    case SLIP_ESCESC:
		outputchr=SLIP_ESC;
		break;
	    default:
		if (!st->ignoring_packet) {
		    Message(M_WARNING, "userv_afterpoll: bad SLIP escape"
			    " character, dropping packet\n");
		}
		st->ignoring_packet=True;
		outputchr=OUTPUT_NOTHING;
		break;
	    }
	} else {
	    switch (buf[i]) {
	    case SLIP_END:
		outputchr=OUTPUT_END;
		break;
	    case SLIP_ESC:
		st->pending_esc=True;
		outputchr=OUTPUT_NOTHING;
		break;
	    default:
		outputchr=buf[i];
		break;
	    }
	}

	if (st->ignoring_packet) {
	    if (outputchr == OUTPUT_END) {
		st->ignoring_packet=False;
		st->buff->size=0;
	    }
	} else {
	    if (outputchr == OUTPUT_END) {
		if (st->buff->size>0) {
		    st->netlink_to_tunnel(&st->nl,st->buff);
		    BUF_ALLOC(st->buff,"userv_afterpoll");
		}
		st->buff->size=0;
	    } else if (outputchr != OUTPUT_NOTHING) {
		if (buf_remaining_space(st->buff)) {
		    buf_append_uint8(st->buff,outputchr);
		} else {
		    Message(M_WARNING, "userv_afterpoll: dropping overlong"
			    " SLIP packet\n");
		    st->ignoring_packet=True;
		}
	    }
	}
    }
}

static void slip_init(struct slip *st, struct cloc loc, dict_t *dict,
		      cstring_t name, netlink_deliver_fn *to_host)
{
    st->netlink_to_tunnel=
	netlink_init(&st->nl,st,loc,dict,
		     "netlink-userv-ipif",NULL,to_host);
    st->buff=find_cl_if(dict,"buffer",CL_BUFFER,True,"name",loc);
    BUF_ALLOC(st->buff,"slip_init");
    st->pending_esc=False;
    st->ignoring_packet=False;
}

/* Connection to the kernel through userv-ipif */

struct userv {
    struct slip slip;
    int txfd; /* We transmit to userv */
    int rxfd; /* We receive from userv */
    cstring_t userv_path;
    cstring_t service_user;
    cstring_t service_name;
    pid_t pid;
    bool_t expecting_userv_exit;
};

static int userv_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
			    int *timeout_io)
{
    struct userv *st=sst;

    if (st->rxfd!=-1) {
	BEFOREPOLL_WANT_FDS(2);
	fds[0].fd=st->txfd;
	fds[0].events=0; /* Might want to pick up POLLOUT sometime */
	fds[1].fd=st->rxfd;
	fds[1].events=POLLIN;
    } else {
	BEFOREPOLL_WANT_FDS(0);
    }
    return 0;
}

static void userv_afterpoll(void *sst, struct pollfd *fds, int nfds)
{
    struct userv *st=sst;
    uint8_t rxbuf[DEFAULT_BUFSIZE];
    int l;

    if (nfds==0) return;

    if (fds[1].revents&POLLERR) {
	Message(M_ERR,"%s: userv_afterpoll: POLLERR!\n",st->slip.nl.name);
    }
    if (fds[1].revents&POLLIN) {
	l=read(st->rxfd,rxbuf,DEFAULT_BUFSIZE);
	if (l<0) {
	    if (errno!=EINTR)
		fatal_perror("%s: userv_afterpoll: read(rxfd)",
			     st->slip.nl.name);
	} else if (l==0) {
	    fatal("%s: userv_afterpoll: read(rxfd)=0; userv gone away?",
		  st->slip.nl.name);
	} else slip_unstuff(&st->slip,rxbuf,l);
    }
}

/* Send buf to the kernel. Free buf before returning. */
static void userv_deliver_to_kernel(void *sst, struct buffer_if *buf)
{
    struct userv *st=sst;

    if (buf->size > st->slip.nl.mtu) {
	Message(M_ERR,"%s: packet of size %"PRIu32" exceeds mtu %"PRIu32":"
		" cannot be injected into kernel, dropped\n",
		st->slip.nl.name, buf->size, st->slip.nl.mtu);
	BUF_FREE(buf);
	return;
    }

    slip_stuff(&st->slip,buf,st->txfd);
}

static void userv_userv_callback(void *sst, pid_t pid, int status)
{
    struct userv *st=sst;

    if (pid!=st->pid) {
	Message(M_WARNING,"userv_callback called unexpectedly with pid %d "
		"(expected %d)\n",pid,st->pid);
	return;
    }
    if (!st->expecting_userv_exit) {
	if (WIFEXITED(status)) {
	    fatal("%s: userv exited unexpectedly with status %d",
		  st->slip.nl.name,WEXITSTATUS(status));
	} else if (WIFSIGNALED(status)) {
	    fatal("%s: userv exited unexpectedly: uncaught signal %d",
		  st->slip.nl.name,WTERMSIG(status));
	} else {
	    fatal("%s: userv stopped unexpectedly",
		  st->slip.nl.name);
	}
    }
    Message(M_WARNING,"%s: userv subprocess died with status %d\n",
	    st->slip.nl.name,WEXITSTATUS(status));
    st->pid=0;
}

struct userv_entry_rec {
    cstring_t path;
    const char **argv;
    int in;
    int out;
    /* XXX perhaps we should collect and log stderr? */
};

static void userv_entry(void *sst)
{
    struct userv_entry_rec *st=sst;

    dup2(st->in,0);
    dup2(st->out,1);

    setsid();
    /* XXX We really should strdup() all of argv[] but because we'll just
       exit anyway if execvp() fails it doesn't seem worth bothering. */
    execvp(st->path,(char *const*)st->argv);
    perror("userv-entry: execvp()");
    exit(1);
}

static void userv_invoke_userv(struct userv *st)
{
    struct userv_entry_rec er[1];
    int c_stdin[2];
    int c_stdout[2];
    string_t nets;
    string_t s;
    struct netlink_client *r;
    struct ipset *allnets;
    struct subnet_list *snets;
    int i, nread;
    uint8_t confirm;

    if (st->pid) {
	fatal("userv_invoke_userv: already running");
    }

    /* This is where we actually invoke userv - all the networks we'll
       be using should already have been registered. */

    char addrs[512];
    snprintf(addrs,sizeof(addrs),"%s,%s,%d,slip",
	     ipaddr_to_string(st->slip.nl.local_address),
	     ipaddr_to_string(st->slip.nl.secnet_address),st->slip.nl.mtu);

    allnets=ipset_new();
    for (r=st->slip.nl.clients; r; r=r->next) {
	if (r->link_quality > LINK_QUALITY_UNUSED) {
	    struct ipset *nan;
	    r->kup=True;
	    nan=ipset_union(allnets,r->networks);
	    ipset_free(allnets);
	    allnets=nan;
	}
    }
    snets=ipset_to_subnet_list(allnets);
    ipset_free(allnets);
    nets=safe_malloc(20*snets->entries,"userv_invoke_userv:nets");
    *nets=0;
    for (i=0; i<snets->entries; i++) {
	s=subnet_to_string(snets->list[i]);
	strcat(nets,s);
	strcat(nets,",");
    }
    nets[strlen(nets)-1]=0;
    subnet_list_free(snets);

    Message(M_INFO,"%s: about to invoke: %s %s %s %s %s\n",st->slip.nl.name,
	    st->userv_path,st->service_user,st->service_name,addrs,nets);

    st->slip.pending_esc=False;

    /* Invoke userv */
    pipe_cloexec(c_stdin);
    pipe_cloexec(c_stdout);
    st->txfd=c_stdin[1];
    st->rxfd=c_stdout[0];

    er->in=c_stdin[0];
    er->out=c_stdout[1];
    /* The arguments are:
       userv
       service-user
       service-name
       local-addr,secnet-addr,mtu,protocol
       route1,route2,... */
    const char *er_argv[6];
    er->argv=er_argv;
    er->argv[0]=st->userv_path;
    er->argv[1]=st->service_user;
    er->argv[2]=st->service_name;
    er->argv[3]=addrs;
    er->argv[4]=nets;
    er->argv[5]=NULL;
    er->path=st->userv_path;

    st->pid=makesubproc(userv_entry, userv_userv_callback,
			er, st, st->slip.nl.name);
    close(er->in);
    close(er->out);
    free(nets);
    Message(M_INFO,"%s: userv-ipif pid is %d\n",st->slip.nl.name,st->pid);
    /* Read a single character from the pipe to confirm userv-ipif is
       running. If we get a SIGCHLD at this point then we'll get EINTR. */
    if ((nread=read(st->rxfd,&confirm,1))!=1) {
	if (errno==EINTR) {
	    Message(M_WARNING,"%s: read of confirmation byte was "
		    "interrupted\n",st->slip.nl.name);
	} else {
	    if (nread<0) {
		fatal_perror("%s: error reading confirmation byte",
			     st->slip.nl.name);
	    } else {
		fatal("%s: unexpected EOF instead of confirmation byte"
		      " - userv ipif failed?", st->slip.nl.name);
	    }
	}
    } else {
	if (confirm!=SLIP_END) {
	    fatal("%s: bad confirmation byte %d from userv-ipif",
		  st->slip.nl.name,confirm);
	}
    }
}

static void userv_kill_userv(struct userv *st)
{
    if (st->pid) {
	kill(-st->pid,SIGTERM);
	st->expecting_userv_exit=True;
    }
}

static void userv_phase_hook(void *sst, uint32_t newphase)
{
    struct userv *st=sst;
    /* We must wait until signal processing has started before forking
       userv */
    if (newphase==PHASE_RUN) {
	userv_invoke_userv(st);
	/* Register for poll() */
	register_for_poll(st, userv_beforepoll, userv_afterpoll,
			  st->slip.nl.name);
    }
    if (newphase==PHASE_SHUTDOWN) {
	userv_kill_userv(st);
    }
}

static list_t *userv_apply(closure_t *self, struct cloc loc, dict_t *context,
			   list_t *args)
{
    struct userv *st;
    item_t *item;
    dict_t *dict;

    st=safe_malloc(sizeof(*st),"userv_apply");

    /* First parameter must be a dict */
    item=list_elem(args,0);
    if (!item || item->type!=t_dict)
	cfgfatal(loc,"userv-ipif","parameter must be a dictionary\n");
    
    dict=item->data.dict;

    slip_init(&st->slip,loc,dict,"netlink-userv-ipif",
	      userv_deliver_to_kernel);

    st->userv_path=dict_read_string(dict,"userv-path",False,"userv-netlink",
				    loc);
    st->service_user=dict_read_string(dict,"service-user",False,
				      "userv-netlink",loc);
    st->service_name=dict_read_string(dict,"service-name",False,
				      "userv-netlink",loc);
    if (!st->userv_path) st->userv_path="userv";
    if (!st->service_user) st->service_user="root";
    if (!st->service_name) st->service_name="ipif";
    st->rxfd=-1; st->txfd=-1;
    st->pid=0;
    st->expecting_userv_exit=False;
    add_hook(PHASE_RUN,userv_phase_hook,st);
    add_hook(PHASE_SHUTDOWN,userv_phase_hook,st);

    return new_closure(&st->slip.nl.cl);
}

void slip_module(dict_t *dict)
{
    add_closure(dict,"userv-ipif",userv_apply);
}
Commit	Line	Data
9d3a4132 SE	1	/* When dealing with SLIP (to a pty, or ipif) we have separate rx, tx
	2	and client buffers. When receiving we may read() any amount, not
	3	just whole packets. When transmitting we need to bytestuff anyway,
	4	and may be part-way through receiving. */
	5
	6	#include "secnet.h"
	7	#include "util.h"
	8	#include "netlink.h"
042a8da9	9	#include "process.h"
993db2a6	10	#include "unaligned.h"
9d3a4132 SE	11	#include <stdio.h>
	12	#include <string.h>
	13	#include <unistd.h>
042a8da9 SE	14	#include <errno.h>
042a8da9 SE	15	#include <fcntl.h>
9d3a4132 SE	16
	17	#define SLIP_END 192
	18	#define SLIP_ESC 219
	19	#define SLIP_ESCEND 220
	20	#define SLIP_ESCESC 221
	21
042a8da9 SE	22	struct slip {
	23	struct netlink nl;
	24	struct buffer_if buff; / We unstuff received packets into here
	25	and send them to the netlink code. */
	26	bool_t pending_esc;
e8a0782f ST	27	bool_t ignoring_packet; /* If this packet was corrupt or overlong,
e8a0782f ST	28	we ignore everything up to the next END */
042a8da9	29	netlink_deliver_fn *netlink_to_tunnel;
042a8da9 SE	30	};
	31
	32	/* Generic SLIP mangling code */
	33
	34	static void slip_stuff(struct slip st, struct buffer_if buf, int fd)
	35	{
	36	uint8_t txbuf[DEFAULT_BUFSIZE];
	37	uint8_t *i;
1caa23ff	38	int32_t j=0;
042a8da9 SE	39
	40	BUF_ASSERT_USED(buf);
	41
d3fe100d	42	/* There's probably a much more efficient way of implementing this */
042a8da9 SE	43	txbuf[j++]=SLIP_END;
	44	for (i=buf->start; i<(buf->start+buf->size); i++) {
	45	switch (*i) {
	46	case SLIP_END:
	47	txbuf[j++]=SLIP_ESC;
	48	txbuf[j++]=SLIP_ESCEND;
	49	break;
	50	case SLIP_ESC:
	51	txbuf[j++]=SLIP_ESC;
	52	txbuf[j++]=SLIP_ESCESC;
	53	break;
	54	default:
	55	txbuf[j++]=*i;
	56	break;
	57	}
	58	if ((j+2)>DEFAULT_BUFSIZE) {
	59	if (write(fd,txbuf,j)<0) {
	60	fatal_perror("slip_stuff: write()");
	61	}
	62	j=0;
	63	}
	64	}
	65	txbuf[j++]=SLIP_END;
	66	if (write(fd,txbuf,j)<0) {
	67	fatal_perror("slip_stuff: write()");
	68	}
	69	BUF_FREE(buf);
	70	}
	71
	72	static void slip_unstuff(struct slip st, uint8_t buf, uint32_t l)
	73	{
	74	uint32_t i;
	75
042a8da9 SE	76	BUF_ASSERT_USED(st->buff);
042a8da9 SE	77	for (i=0; i<l; i++) {
e8a0782f ST	78	int outputchr;
	79	enum { OUTPUT_END = 256, OUTPUT_NOTHING = 257 };
	80
a28d65a5 IJ	81	if (!st->buff->size)
	82	buffer_init(st->buff,calculate_max_start_pad());
	83
042a8da9 SE	84	if (st->pending_esc) {
	85	st->pending_esc=False;
	86	switch(buf[i]) {
	87	case SLIP_ESCEND:
e8a0782f	88	outputchr=SLIP_END;
042a8da9 SE	89	break;
042a8da9 SE	90	case SLIP_ESCESC:
e8a0782f	91	outputchr=SLIP_ESC;
042a8da9 SE	92	break;
042a8da9 SE	93	default:
e8a0782f ST	94	if (!st->ignoring_packet) {
	95	Message(M_WARNING, "userv_afterpoll: bad SLIP escape"
	96	" character, dropping packet\n");
	97	}
	98	st->ignoring_packet=True;
	99	outputchr=OUTPUT_NOTHING;
	100	break;
042a8da9 SE	101	}
	102	} else {
	103	switch (buf[i]) {
	104	case SLIP_END:
e8a0782f	105	outputchr=OUTPUT_END;
042a8da9 SE	106	break;
	107	case SLIP_ESC:
	108	st->pending_esc=True;
e8a0782f	109	outputchr=OUTPUT_NOTHING;
042a8da9 SE	110	break;
042a8da9 SE	111	default:
e8a0782f	112	outputchr=buf[i];
042a8da9 SE	113	break;
	114	}
	115	}
e8a0782f ST	116
	117	if (st->ignoring_packet) {
	118	if (outputchr == OUTPUT_END) {
	119	st->ignoring_packet=False;
a28d65a5	120	st->buff->size=0;
e8a0782f ST	121	}
	122	} else {
	123	if (outputchr == OUTPUT_END) {
	124	if (st->buff->size>0) {
	125	st->netlink_to_tunnel(&st->nl,st->buff);
	126	BUF_ALLOC(st->buff,"userv_afterpoll");
	127	}
a28d65a5	128	st->buff->size=0;
e8a0782f	129	} else if (outputchr != OUTPUT_NOTHING) {
92795040	130	if (buf_remaining_space(st->buff)) {
993db2a6	131	buf_append_uint8(st->buff,outputchr);
e8a0782f ST	132	} else {
	133	Message(M_WARNING, "userv_afterpoll: dropping overlong"
	134	" SLIP packet\n");
	135	st->ignoring_packet=True;
	136	}
	137	}
	138	}
042a8da9 SE	139	}
	140	}
	141
	142	static void slip_init(struct slip st, struct cloc loc, dict_t dict,
fe5e9cc4	143	cstring_t name, netlink_deliver_fn *to_host)
042a8da9 SE	144	{
	145	st->netlink_to_tunnel=
	146	netlink_init(&st->nl,st,loc,dict,
	147	"netlink-userv-ipif",NULL,to_host);
	148	st->buff=find_cl_if(dict,"buffer",CL_BUFFER,True,"name",loc);
042a8da9 SE	149	BUF_ALLOC(st->buff,"slip_init");
042a8da9 SE	150	st->pending_esc=False;
e8a0782f	151	st->ignoring_packet=False;
042a8da9 SE	152	}
042a8da9 SE	153
9d3a4132 SE	154	/* Connection to the kernel through userv-ipif */
	155
	156	struct userv {
042a8da9	157	struct slip slip;
9d3a4132 SE	158	int txfd; /* We transmit to userv */
9d3a4132 SE	159	int rxfd; /* We receive from userv */
fe5e9cc4 SE	160	cstring_t userv_path;
	161	cstring_t service_user;
	162	cstring_t service_name;
042a8da9 SE	163	pid_t pid;
042a8da9 SE	164	bool_t expecting_userv_exit;
9d3a4132 SE	165	};
	166
	167	static int userv_beforepoll(void sst, struct pollfd fds, int *nfds_io,
90a39563	168	int *timeout_io)
9d3a4132 SE	169	{
9d3a4132 SE	170	struct userv *st=sst;
042a8da9 SE	171
042a8da9 SE	172	if (st->rxfd!=-1) {
ee697dd9	173	BEFOREPOLL_WANT_FDS(2);
042a8da9	174	fds[0].fd=st->txfd;
fe5e9cc4	175	fds[0].events=0; /* Might want to pick up POLLOUT sometime */
042a8da9	176	fds[1].fd=st->rxfd;
fe5e9cc4	177	fds[1].events=POLLIN;
042a8da9	178	} else {
ee697dd9	179	BEFOREPOLL_WANT_FDS(0);
042a8da9	180	}
9d3a4132 SE	181	return 0;
	182	}
	183
90a39563	184	static void userv_afterpoll(void sst, struct pollfd fds, int nfds)
9d3a4132 SE	185	{
	186	struct userv *st=sst;
	187	uint8_t rxbuf[DEFAULT_BUFSIZE];
042a8da9 SE	188	int l;
	189
	190	if (nfds==0) return;
9d3a4132 SE	191
9d3a4132 SE	192	if (fds[1].revents&POLLERR) {
469fd1d9	193	Message(M_ERR,"%s: userv_afterpoll: POLLERR!\n",st->slip.nl.name);
9d3a4132 SE	194	}
	195	if (fds[1].revents&POLLIN) {
	196	l=read(st->rxfd,rxbuf,DEFAULT_BUFSIZE);
	197	if (l<0) {
042a8da9 SE	198	if (errno!=EINTR)
	199	fatal_perror("%s: userv_afterpoll: read(rxfd)",
	200	st->slip.nl.name);
	201	} else if (l==0) {
4f5e39ec	202	fatal("%s: userv_afterpoll: read(rxfd)=0; userv gone away?",
042a8da9 SE	203	st->slip.nl.name);
042a8da9 SE	204	} else slip_unstuff(&st->slip,rxbuf,l);
9d3a4132 SE	205	}
	206	}
	207
	208	/* Send buf to the kernel. Free buf before returning. */
469fd1d9	209	static void userv_deliver_to_kernel(void sst, struct buffer_if buf)
9d3a4132 SE	210	{
9d3a4132 SE	211	struct userv *st=sst;
9d3a4132	212
32240a83 IJ	213	if (buf->size > st->slip.nl.mtu) {
	214	Message(M_ERR,"%s: packet of size %"PRIu32" exceeds mtu %"PRIu32":"
	215	" cannot be injected into kernel, dropped\n",
	216	st->slip.nl.name, buf->size, st->slip.nl.mtu);
	217	BUF_FREE(buf);
	218	return;
	219	}
	220
042a8da9 SE	221	slip_stuff(&st->slip,buf,st->txfd);
042a8da9 SE	222	}
9d3a4132	223
042a8da9 SE	224	static void userv_userv_callback(void *sst, pid_t pid, int status)
	225	{
	226	struct userv *st=sst;
	227
	228	if (pid!=st->pid) {
	229	Message(M_WARNING,"userv_callback called unexpectedly with pid %d "
	230	"(expected %d)\n",pid,st->pid);
	231	return;
9d3a4132	232	}
042a8da9 SE	233	if (!st->expecting_userv_exit) {
042a8da9 SE	234	if (WIFEXITED(status)) {
4f5e39ec	235	fatal("%s: userv exited unexpectedly with status %d",
042a8da9 SE	236	st->slip.nl.name,WEXITSTATUS(status));
042a8da9 SE	237	} else if (WIFSIGNALED(status)) {
4f5e39ec	238	fatal("%s: userv exited unexpectedly: uncaught signal %d",
042a8da9 SE	239	st->slip.nl.name,WTERMSIG(status));
042a8da9 SE	240	} else {
779837e1 IJ	241	fatal("%s: userv stopped unexpectedly",
779837e1 IJ	242	st->slip.nl.name);
042a8da9	243	}
9d3a4132	244	}
042a8da9 SE	245	Message(M_WARNING,"%s: userv subprocess died with status %d\n",
	246	st->slip.nl.name,WEXITSTATUS(status));
	247	st->pid=0;
9d3a4132 SE	248	}
9d3a4132 SE	249
042a8da9	250	struct userv_entry_rec {
fe5e9cc4 SE	251	cstring_t path;
fe5e9cc4 SE	252	const char **argv;
469fd1d9 SE	253	int in;
469fd1d9 SE	254	int out;
042a8da9 SE	255	/* XXX perhaps we should collect and log stderr? */
	256	};
	257
	258	static void userv_entry(void *sst)
9d3a4132	259	{
042a8da9 SE	260	struct userv_entry_rec *st=sst;
042a8da9 SE	261
469fd1d9 SE	262	dup2(st->in,0);
469fd1d9 SE	263	dup2(st->out,1);
042a8da9	264
042a8da9	265	setsid();
fe5e9cc4 SE	266	/* XXX We really should strdup() all of argv[] but because we'll just
	267	exit anyway if execvp() fails it doesn't seem worth bothering. */
	268	execvp(st->path,(char const)st->argv);
042a8da9 SE	269	perror("userv-entry: execvp()");
	270	exit(1);
	271	}
	272
	273	static void userv_invoke_userv(struct userv *st)
	274	{
f665113d	275	struct userv_entry_rec er[1];
9d3a4132 SE	276	int c_stdin[2];
9d3a4132 SE	277	int c_stdout[2];
9d3a4132 SE	278	string_t nets;
9d3a4132 SE	279	string_t s;
d3fe100d SE	280	struct netlink_client *r;
d3fe100d SE	281	struct ipset *allnets;
794f2398	282	struct subnet_list *snets;
4f5e39ec	283	int i, nread;
042a8da9 SE	284	uint8_t confirm;
	285
	286	if (st->pid) {
4f5e39ec	287	fatal("userv_invoke_userv: already running");
042a8da9	288	}
9d3a4132 SE	289
	290	/* This is where we actually invoke userv - all the networks we'll
	291	be using should already have been registered. */
	292
f665113d IJ	293	char addrs[512];
f665113d IJ	294	snprintf(addrs,sizeof(addrs),"%s,%s,%d,slip",
091433c6	295	ipaddr_to_string(st->slip.nl.local_address),
042a8da9	296	ipaddr_to_string(st->slip.nl.secnet_address),st->slip.nl.mtu);
9d3a4132	297
d3fe100d SE	298	allnets=ipset_new();
d3fe100d SE	299	for (r=st->slip.nl.clients; r; r=r->next) {
f208b9a9 IJ	300	if (r->link_quality > LINK_QUALITY_UNUSED) {
	301	struct ipset *nan;
	302	r->kup=True;
	303	nan=ipset_union(allnets,r->networks);
	304	ipset_free(allnets);
	305	allnets=nan;
	306	}
9d3a4132	307	}
d3fe100d SE	308	snets=ipset_to_subnet_list(allnets);
d3fe100d SE	309	ipset_free(allnets);
794f2398 SE	310	nets=safe_malloc(20*snets->entries,"userv_invoke_userv:nets");
	311	*nets=0;
	312	for (i=0; i<snets->entries; i++) {
	313	s=subnet_to_string(snets->list[i]);
	314	strcat(nets,s);
	315	strcat(nets,",");
794f2398	316	}
9d3a4132	317	nets[strlen(nets)-1]=0;
794f2398	318	subnet_list_free(snets);
9d3a4132	319
042a8da9	320	Message(M_INFO,"%s: about to invoke: %s %s %s %s %s\n",st->slip.nl.name,
9d3a4132 SE	321	st->userv_path,st->service_user,st->service_name,addrs,nets);
9d3a4132 SE	322
042a8da9	323	st->slip.pending_esc=False;
9d3a4132 SE	324
9d3a4132 SE	325	/* Invoke userv */
6a06198c IJ	326	pipe_cloexec(c_stdin);
6a06198c IJ	327	pipe_cloexec(c_stdout);
9d3a4132 SE	328	st->txfd=c_stdin[1];
	329	st->rxfd=c_stdout[0];
	330
469fd1d9 SE	331	er->in=c_stdin[0];
469fd1d9 SE	332	er->out=c_stdout[1];
042a8da9 SE	333	/* The arguments are:
	334	userv
	335	service-user
	336	service-name
	337	local-addr,secnet-addr,mtu,protocol
	338	route1,route2,... */
f665113d IJ	339	const char *er_argv[6];
f665113d IJ	340	er->argv=er_argv;
042a8da9 SE	341	er->argv[0]=st->userv_path;
	342	er->argv[1]=st->service_user;
	343	er->argv[2]=st->service_name;
	344	er->argv[3]=addrs;
	345	er->argv[4]=nets;
	346	er->argv[5]=NULL;
	347	er->path=st->userv_path;
	348
	349	st->pid=makesubproc(userv_entry, userv_userv_callback,
	350	er, st, st->slip.nl.name);
469fd1d9 SE	351	close(er->in);
469fd1d9 SE	352	close(er->out);
042a8da9 SE	353	free(nets);
	354	Message(M_INFO,"%s: userv-ipif pid is %d\n",st->slip.nl.name,st->pid);
	355	/* Read a single character from the pipe to confirm userv-ipif is
	356	running. If we get a SIGCHLD at this point then we'll get EINTR. */
4f5e39ec	357	if ((nread=read(st->rxfd,&confirm,1))!=1) {
042a8da9 SE	358	if (errno==EINTR) {
	359	Message(M_WARNING,"%s: read of confirmation byte was "
	360	"interrupted\n",st->slip.nl.name);
	361	} else {
4f5e39ec SE	362	if (nread<0) {
	363	fatal_perror("%s: error reading confirmation byte",
	364	st->slip.nl.name);
	365	} else {
	366	fatal("%s: unexpected EOF instead of confirmation byte"
	367	" - userv ipif failed?", st->slip.nl.name);
	368	}
042a8da9 SE	369	}
	370	} else {
	371	if (confirm!=SLIP_END) {
4f5e39ec	372	fatal("%s: bad confirmation byte %d from userv-ipif",
042a8da9 SE	373	st->slip.nl.name,confirm);
042a8da9 SE	374	}
9d3a4132	375	}
042a8da9 SE	376	}
	377
	378	static void userv_kill_userv(struct userv *st)
	379	{
	380	if (st->pid) {
	381	kill(-st->pid,SIGTERM);
	382	st->expecting_userv_exit=True;
	383	}
	384	}
	385
	386	static void userv_phase_hook(void *sst, uint32_t newphase)
	387	{
	388	struct userv *st=sst;
	389	/* We must wait until signal processing has started before forking
	390	userv */
	391	if (newphase==PHASE_RUN) {
	392	userv_invoke_userv(st);
	393	/* Register for poll() */
32fc582f	394	register_for_poll(st, userv_beforepoll, userv_afterpoll,
042a8da9 SE	395	st->slip.nl.name);
	396	}
	397	if (newphase==PHASE_SHUTDOWN) {
	398	userv_kill_userv(st);
9d3a4132	399	}
9d3a4132 SE	400	}
	401
	402	static list_t userv_apply(closure_t self, struct cloc loc, dict_t *context,
	403	list_t *args)
	404	{
	405	struct userv *st;
	406	item_t *item;
	407	dict_t *dict;
	408
	409	st=safe_malloc(sizeof(*st),"userv_apply");
	410
	411	/* First parameter must be a dict */
	412	item=list_elem(args,0);
	413	if (!item \|\| item->type!=t_dict)
	414	cfgfatal(loc,"userv-ipif","parameter must be a dictionary\n");
	415
	416	dict=item->data.dict;
	417
042a8da9 SE	418	slip_init(&st->slip,loc,dict,"netlink-userv-ipif",
042a8da9 SE	419	userv_deliver_to_kernel);
9d3a4132 SE	420
	421	st->userv_path=dict_read_string(dict,"userv-path",False,"userv-netlink",
	422	loc);
	423	st->service_user=dict_read_string(dict,"service-user",False,
	424	"userv-netlink",loc);
	425	st->service_name=dict_read_string(dict,"service-name",False,
	426	"userv-netlink",loc);
	427	if (!st->userv_path) st->userv_path="userv";
	428	if (!st->service_user) st->service_user="root";
	429	if (!st->service_name) st->service_name="ipif";
9d3a4132	430	st->rxfd=-1; st->txfd=-1;
042a8da9 SE	431	st->pid=0;
	432	st->expecting_userv_exit=False;
	433	add_hook(PHASE_RUN,userv_phase_hook,st);
	434	add_hook(PHASE_SHUTDOWN,userv_phase_hook,st);
9d3a4132	435
042a8da9	436	return new_closure(&st->slip.nl.cl);
9d3a4132 SE	437	}
9d3a4132 SE	438
9d3a4132 SE	439	void slip_module(dict_t *dict)
	440	{
	441	add_closure(dict,"userv-ipif",userv_apply);
9d3a4132	442	}