[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_write(int fd, const uint8_t *p, size_t l)
{
    while (l) {
	ssize_t written=write(fd,p,l);
	if (written<0) {
	    if (errno==EINTR) {
		continue;
	    } else if (iswouldblock(errno)) {
		lg_perror(0,"slip",0,M_ERR,errno,"write() (packet(s) lost)");
		return;
	    } else {
		fatal_perror("slip_stuff: write()");
	    }
	}
	assert(written>0);
	assert((size_t)written<=l);
	p+=written;
	l-=written;
    }
}

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) {
	    slip_write(fd,txbuf,j);
	    j=0;
	}
    }
    txbuf[j++]=SLIP_END;
    slip_write(fd,txbuf,j);
    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 && !iswouldblock(errno))
		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 &&
	  (!status ||
	   (WIFSIGNALED(status) && WTERMSIG(status)==SIGTERM)))) {
	lg_exitstatus(0,st->slip.nl.name,0,
		      st->expecting_userv_exit ? M_WARNING : M_FATAL,
		      status,"userv");
    }
    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();
    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);
	}
    }
    setnonblock(st->txfd);
    setnonblock(st->rxfd);

    add_hook(PHASE_CHILDPERSIST,childpersist_closefd_hook,&st->txfd);
    add_hook(PHASE_CHILDPERSIST,childpersist_closefd_hook,&st->rxfd);
}

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;

    NEW(st);

    /* 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
ba703386 IJ	34	static void slip_write(int fd, const uint8_t *p, size_t l)
	35	{
	36	while (l) {
	37	ssize_t written=write(fd,p,l);
	38	if (written<0) {
	39	if (errno==EINTR) {
	40	continue;
	41	} else if (iswouldblock(errno)) {
	42	lg_perror(0,"slip",0,M_ERR,errno,"write() (packet(s) lost)");
	43	return;
	44	} else {
	45	fatal_perror("slip_stuff: write()");
	46	}
	47	}
	48	assert(written>0);
	49	assert((size_t)written<=l);
	50	p+=written;
	51	l-=written;
	52	}
	53	}
	54
042a8da9 SE	55	static void slip_stuff(struct slip st, struct buffer_if buf, int fd)
	56	{
	57	uint8_t txbuf[DEFAULT_BUFSIZE];
	58	uint8_t *i;
1caa23ff	59	int32_t j=0;
042a8da9 SE	60
	61	BUF_ASSERT_USED(buf);
	62
d3fe100d	63	/* There's probably a much more efficient way of implementing this */
042a8da9 SE	64	txbuf[j++]=SLIP_END;
	65	for (i=buf->start; i<(buf->start+buf->size); i++) {
	66	switch (*i) {
	67	case SLIP_END:
	68	txbuf[j++]=SLIP_ESC;
	69	txbuf[j++]=SLIP_ESCEND;
	70	break;
	71	case SLIP_ESC:
	72	txbuf[j++]=SLIP_ESC;
	73	txbuf[j++]=SLIP_ESCESC;
	74	break;
	75	default:
	76	txbuf[j++]=*i;
	77	break;
	78	}
	79	if ((j+2)>DEFAULT_BUFSIZE) {
ba703386	80	slip_write(fd,txbuf,j);
042a8da9 SE	81	j=0;
	82	}
	83	}
	84	txbuf[j++]=SLIP_END;
ba703386	85	slip_write(fd,txbuf,j);
042a8da9 SE	86	BUF_FREE(buf);
	87	}
	88
	89	static void slip_unstuff(struct slip st, uint8_t buf, uint32_t l)
	90	{
	91	uint32_t i;
	92
042a8da9 SE	93	BUF_ASSERT_USED(st->buff);
042a8da9 SE	94	for (i=0; i<l; i++) {
e8a0782f ST	95	int outputchr;
	96	enum { OUTPUT_END = 256, OUTPUT_NOTHING = 257 };
	97
a28d65a5 IJ	98	if (!st->buff->size)
	99	buffer_init(st->buff,calculate_max_start_pad());
	100
042a8da9 SE	101	if (st->pending_esc) {
	102	st->pending_esc=False;
	103	switch(buf[i]) {
	104	case SLIP_ESCEND:
e8a0782f	105	outputchr=SLIP_END;
042a8da9 SE	106	break;
042a8da9 SE	107	case SLIP_ESCESC:
e8a0782f	108	outputchr=SLIP_ESC;
042a8da9 SE	109	break;
042a8da9 SE	110	default:
e8a0782f ST	111	if (!st->ignoring_packet) {
	112	Message(M_WARNING, "userv_afterpoll: bad SLIP escape"
	113	" character, dropping packet\n");
	114	}
	115	st->ignoring_packet=True;
	116	outputchr=OUTPUT_NOTHING;
	117	break;
042a8da9 SE	118	}
	119	} else {
	120	switch (buf[i]) {
	121	case SLIP_END:
e8a0782f	122	outputchr=OUTPUT_END;
042a8da9 SE	123	break;
	124	case SLIP_ESC:
	125	st->pending_esc=True;
e8a0782f	126	outputchr=OUTPUT_NOTHING;
042a8da9 SE	127	break;
042a8da9 SE	128	default:
e8a0782f	129	outputchr=buf[i];
042a8da9 SE	130	break;
	131	}
	132	}
e8a0782f ST	133
	134	if (st->ignoring_packet) {
	135	if (outputchr == OUTPUT_END) {
	136	st->ignoring_packet=False;
a28d65a5	137	st->buff->size=0;
e8a0782f ST	138	}
	139	} else {
	140	if (outputchr == OUTPUT_END) {
	141	if (st->buff->size>0) {
	142	st->netlink_to_tunnel(&st->nl,st->buff);
	143	BUF_ALLOC(st->buff,"userv_afterpoll");
	144	}
a28d65a5	145	st->buff->size=0;
e8a0782f	146	} else if (outputchr != OUTPUT_NOTHING) {
92795040	147	if (buf_remaining_space(st->buff)) {
993db2a6	148	buf_append_uint8(st->buff,outputchr);
e8a0782f ST	149	} else {
	150	Message(M_WARNING, "userv_afterpoll: dropping overlong"
	151	" SLIP packet\n");
	152	st->ignoring_packet=True;
	153	}
	154	}
	155	}
042a8da9 SE	156	}
	157	}
	158
	159	static void slip_init(struct slip st, struct cloc loc, dict_t dict,
fe5e9cc4	160	cstring_t name, netlink_deliver_fn *to_host)
042a8da9 SE	161	{
	162	st->netlink_to_tunnel=
	163	netlink_init(&st->nl,st,loc,dict,
	164	"netlink-userv-ipif",NULL,to_host);
	165	st->buff=find_cl_if(dict,"buffer",CL_BUFFER,True,"name",loc);
042a8da9 SE	166	BUF_ALLOC(st->buff,"slip_init");
042a8da9 SE	167	st->pending_esc=False;
e8a0782f	168	st->ignoring_packet=False;
042a8da9 SE	169	}
042a8da9 SE	170
9d3a4132 SE	171	/* Connection to the kernel through userv-ipif */
	172
	173	struct userv {
042a8da9	174	struct slip slip;
9d3a4132 SE	175	int txfd; /* We transmit to userv */
9d3a4132 SE	176	int rxfd; /* We receive from userv */
fe5e9cc4 SE	177	cstring_t userv_path;
	178	cstring_t service_user;
	179	cstring_t service_name;
042a8da9 SE	180	pid_t pid;
042a8da9 SE	181	bool_t expecting_userv_exit;
9d3a4132 SE	182	};
	183
	184	static int userv_beforepoll(void sst, struct pollfd fds, int *nfds_io,
90a39563	185	int *timeout_io)
9d3a4132 SE	186	{
9d3a4132 SE	187	struct userv *st=sst;
042a8da9 SE	188
042a8da9 SE	189	if (st->rxfd!=-1) {
ee697dd9	190	BEFOREPOLL_WANT_FDS(2);
042a8da9	191	fds[0].fd=st->txfd;
fe5e9cc4	192	fds[0].events=0; /* Might want to pick up POLLOUT sometime */
042a8da9	193	fds[1].fd=st->rxfd;
fe5e9cc4	194	fds[1].events=POLLIN;
042a8da9	195	} else {
ee697dd9	196	BEFOREPOLL_WANT_FDS(0);
042a8da9	197	}
9d3a4132 SE	198	return 0;
	199	}
	200
90a39563	201	static void userv_afterpoll(void sst, struct pollfd fds, int nfds)
9d3a4132 SE	202	{
	203	struct userv *st=sst;
	204	uint8_t rxbuf[DEFAULT_BUFSIZE];
042a8da9 SE	205	int l;
	206
	207	if (nfds==0) return;
9d3a4132 SE	208
9d3a4132 SE	209	if (fds[1].revents&POLLERR) {
469fd1d9	210	Message(M_ERR,"%s: userv_afterpoll: POLLERR!\n",st->slip.nl.name);
9d3a4132 SE	211	}
	212	if (fds[1].revents&POLLIN) {
	213	l=read(st->rxfd,rxbuf,DEFAULT_BUFSIZE);
	214	if (l<0) {
ba703386	215	if (errno!=EINTR && !iswouldblock(errno))
042a8da9 SE	216	fatal_perror("%s: userv_afterpoll: read(rxfd)",
	217	st->slip.nl.name);
	218	} else if (l==0) {
4f5e39ec	219	fatal("%s: userv_afterpoll: read(rxfd)=0; userv gone away?",
042a8da9 SE	220	st->slip.nl.name);
042a8da9 SE	221	} else slip_unstuff(&st->slip,rxbuf,l);
9d3a4132 SE	222	}
	223	}
	224
	225	/* Send buf to the kernel. Free buf before returning. */
469fd1d9	226	static void userv_deliver_to_kernel(void sst, struct buffer_if buf)
9d3a4132 SE	227	{
9d3a4132 SE	228	struct userv *st=sst;
9d3a4132	229
32240a83 IJ	230	if (buf->size > st->slip.nl.mtu) {
	231	Message(M_ERR,"%s: packet of size %"PRIu32" exceeds mtu %"PRIu32":"
	232	" cannot be injected into kernel, dropped\n",
	233	st->slip.nl.name, buf->size, st->slip.nl.mtu);
	234	BUF_FREE(buf);
	235	return;
	236	}
	237
042a8da9 SE	238	slip_stuff(&st->slip,buf,st->txfd);
042a8da9 SE	239	}
9d3a4132	240
042a8da9 SE	241	static void userv_userv_callback(void *sst, pid_t pid, int status)
	242	{
	243	struct userv *st=sst;
	244
	245	if (pid!=st->pid) {
	246	Message(M_WARNING,"userv_callback called unexpectedly with pid %d "
	247	"(expected %d)\n",pid,st->pid);
	248	return;
9d3a4132	249	}
6b30affc IJ	250	if (!(st->expecting_userv_exit &&
	251	(!status \|\|
	252	(WIFSIGNALED(status) && WTERMSIG(status)==SIGTERM)))) {
4ac7fd3f IJ	253	lg_exitstatus(0,st->slip.nl.name,0,
	254	st->expecting_userv_exit ? M_WARNING : M_FATAL,
	255	status,"userv");
9d3a4132	256	}
042a8da9	257	st->pid=0;
9d3a4132 SE	258	}
9d3a4132 SE	259
042a8da9	260	struct userv_entry_rec {
fe5e9cc4 SE	261	cstring_t path;
fe5e9cc4 SE	262	const char **argv;
469fd1d9 SE	263	int in;
469fd1d9 SE	264	int out;
042a8da9 SE	265	/* XXX perhaps we should collect and log stderr? */
	266	};
	267
	268	static void userv_entry(void *sst)
9d3a4132	269	{
042a8da9 SE	270	struct userv_entry_rec *st=sst;
042a8da9 SE	271
469fd1d9 SE	272	dup2(st->in,0);
469fd1d9 SE	273	dup2(st->out,1);
042a8da9	274
042a8da9	275	setsid();
fe5e9cc4	276	execvp(st->path,(char const)st->argv);
042a8da9 SE	277	perror("userv-entry: execvp()");
	278	exit(1);
	279	}
	280
	281	static void userv_invoke_userv(struct userv *st)
	282	{
f665113d	283	struct userv_entry_rec er[1];
9d3a4132 SE	284	int c_stdin[2];
9d3a4132 SE	285	int c_stdout[2];
9d3a4132 SE	286	string_t nets;
9d3a4132 SE	287	string_t s;
d3fe100d SE	288	struct netlink_client *r;
d3fe100d SE	289	struct ipset *allnets;
794f2398	290	struct subnet_list *snets;
4f5e39ec	291	int i, nread;
042a8da9 SE	292	uint8_t confirm;
	293
	294	if (st->pid) {
4f5e39ec	295	fatal("userv_invoke_userv: already running");
042a8da9	296	}
9d3a4132 SE	297
	298	/* This is where we actually invoke userv - all the networks we'll
	299	be using should already have been registered. */
	300
f665113d IJ	301	char addrs[512];
f665113d IJ	302	snprintf(addrs,sizeof(addrs),"%s,%s,%d,slip",
091433c6	303	ipaddr_to_string(st->slip.nl.local_address),
042a8da9	304	ipaddr_to_string(st->slip.nl.secnet_address),st->slip.nl.mtu);
9d3a4132	305
d3fe100d SE	306	allnets=ipset_new();
d3fe100d SE	307	for (r=st->slip.nl.clients; r; r=r->next) {
f208b9a9 IJ	308	if (r->link_quality > LINK_QUALITY_UNUSED) {
	309	struct ipset *nan;
	310	r->kup=True;
	311	nan=ipset_union(allnets,r->networks);
	312	ipset_free(allnets);
	313	allnets=nan;
	314	}
9d3a4132	315	}
d3fe100d SE	316	snets=ipset_to_subnet_list(allnets);
d3fe100d SE	317	ipset_free(allnets);
794f2398 SE	318	nets=safe_malloc(20*snets->entries,"userv_invoke_userv:nets");
	319	*nets=0;
	320	for (i=0; i<snets->entries; i++) {
	321	s=subnet_to_string(snets->list[i]);
	322	strcat(nets,s);
	323	strcat(nets,",");
794f2398	324	}
9d3a4132	325	nets[strlen(nets)-1]=0;
794f2398	326	subnet_list_free(snets);
9d3a4132	327
042a8da9	328	Message(M_INFO,"%s: about to invoke: %s %s %s %s %s\n",st->slip.nl.name,
9d3a4132 SE	329	st->userv_path,st->service_user,st->service_name,addrs,nets);
9d3a4132 SE	330
042a8da9	331	st->slip.pending_esc=False;
9d3a4132 SE	332
9d3a4132 SE	333	/* Invoke userv */
6a06198c IJ	334	pipe_cloexec(c_stdin);
6a06198c IJ	335	pipe_cloexec(c_stdout);
9d3a4132 SE	336	st->txfd=c_stdin[1];
	337	st->rxfd=c_stdout[0];
	338
469fd1d9 SE	339	er->in=c_stdin[0];
469fd1d9 SE	340	er->out=c_stdout[1];
042a8da9 SE	341	/* The arguments are:
	342	userv
	343	service-user
	344	service-name
	345	local-addr,secnet-addr,mtu,protocol
	346	route1,route2,... */
f665113d IJ	347	const char *er_argv[6];
f665113d IJ	348	er->argv=er_argv;
042a8da9 SE	349	er->argv[0]=st->userv_path;
	350	er->argv[1]=st->service_user;
	351	er->argv[2]=st->service_name;
	352	er->argv[3]=addrs;
	353	er->argv[4]=nets;
	354	er->argv[5]=NULL;
	355	er->path=st->userv_path;
	356
	357	st->pid=makesubproc(userv_entry, userv_userv_callback,
	358	er, st, st->slip.nl.name);
469fd1d9 SE	359	close(er->in);
469fd1d9 SE	360	close(er->out);
042a8da9 SE	361	free(nets);
	362	Message(M_INFO,"%s: userv-ipif pid is %d\n",st->slip.nl.name,st->pid);
	363	/* Read a single character from the pipe to confirm userv-ipif is
	364	running. If we get a SIGCHLD at this point then we'll get EINTR. */
4f5e39ec	365	if ((nread=read(st->rxfd,&confirm,1))!=1) {
042a8da9 SE	366	if (errno==EINTR) {
	367	Message(M_WARNING,"%s: read of confirmation byte was "
	368	"interrupted\n",st->slip.nl.name);
	369	} else {
4f5e39ec SE	370	if (nread<0) {
	371	fatal_perror("%s: error reading confirmation byte",
	372	st->slip.nl.name);
	373	} else {
	374	fatal("%s: unexpected EOF instead of confirmation byte"
	375	" - userv ipif failed?", st->slip.nl.name);
	376	}
042a8da9 SE	377	}
	378	} else {
	379	if (confirm!=SLIP_END) {
4f5e39ec	380	fatal("%s: bad confirmation byte %d from userv-ipif",
042a8da9 SE	381	st->slip.nl.name,confirm);
042a8da9 SE	382	}
9d3a4132	383	}
ba703386 IJ	384	setnonblock(st->txfd);
ba703386 IJ	385	setnonblock(st->rxfd);
32654a31 IJ	386
	387	add_hook(PHASE_CHILDPERSIST,childpersist_closefd_hook,&st->txfd);
	388	add_hook(PHASE_CHILDPERSIST,childpersist_closefd_hook,&st->rxfd);
042a8da9 SE	389	}
	390
	391	static void userv_kill_userv(struct userv *st)
	392	{
	393	if (st->pid) {
	394	kill(-st->pid,SIGTERM);
	395	st->expecting_userv_exit=True;
	396	}
	397	}
	398
	399	static void userv_phase_hook(void *sst, uint32_t newphase)
	400	{
	401	struct userv *st=sst;
	402	/* We must wait until signal processing has started before forking
	403	userv */
	404	if (newphase==PHASE_RUN) {
	405	userv_invoke_userv(st);
	406	/* Register for poll() */
32fc582f	407	register_for_poll(st, userv_beforepoll, userv_afterpoll,
042a8da9 SE	408	st->slip.nl.name);
	409	}
	410	if (newphase==PHASE_SHUTDOWN) {
	411	userv_kill_userv(st);
9d3a4132	412	}
9d3a4132 SE	413	}
	414
	415	static list_t userv_apply(closure_t self, struct cloc loc, dict_t *context,
	416	list_t *args)
	417	{
	418	struct userv *st;
	419	item_t *item;
	420	dict_t *dict;
	421
b7886fd4	422	NEW(st);
9d3a4132 SE	423
	424	/* First parameter must be a dict */
	425	item=list_elem(args,0);
	426	if (!item \|\| item->type!=t_dict)
	427	cfgfatal(loc,"userv-ipif","parameter must be a dictionary\n");
	428
	429	dict=item->data.dict;
	430
042a8da9 SE	431	slip_init(&st->slip,loc,dict,"netlink-userv-ipif",
042a8da9 SE	432	userv_deliver_to_kernel);
9d3a4132 SE	433
	434	st->userv_path=dict_read_string(dict,"userv-path",False,"userv-netlink",
	435	loc);
	436	st->service_user=dict_read_string(dict,"service-user",False,
	437	"userv-netlink",loc);
	438	st->service_name=dict_read_string(dict,"service-name",False,
	439	"userv-netlink",loc);
	440	if (!st->userv_path) st->userv_path="userv";
	441	if (!st->service_user) st->service_user="root";
	442	if (!st->service_name) st->service_name="ipif";
9d3a4132	443	st->rxfd=-1; st->txfd=-1;
042a8da9 SE	444	st->pid=0;
	445	st->expecting_userv_exit=False;
	446	add_hook(PHASE_RUN,userv_phase_hook,st);
	447	add_hook(PHASE_SHUTDOWN,userv_phase_hook,st);
9d3a4132	448
042a8da9	449	return new_closure(&st->slip.nl.cl);
9d3a4132 SE	450	}
9d3a4132 SE	451
9d3a4132 SE	452	void slip_module(dict_t *dict)
	453	{
	454	add_closure(dict,"userv-ipif",userv_apply);
9d3a4132	455	}