[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;
    uint32_t local_address;
};

/* 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 (st->buff->size < st->buff->len) {
		    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);
    st->local_address=string_item_to_ipaddr(
	dict_find_item(dict,"local-address", True, name, loc),"netlink");
    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) {
	*nfds_io=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 {
	*nfds_io=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;

    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);

    /* XXX close all other fds */
    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;
    int c_stdin[2];
    int c_stdout[2];
    string_t addrs;
    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. */

    addrs=safe_malloc(512,"userv_invoke_userv:addrs");
    snprintf(addrs,512,"%s,%s,%d,slip",
	     ipaddr_to_string(st->slip.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,",");
	free(s);
    }
    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 */
    if (pipe(c_stdin)!=0) {
	fatal_perror("userv_invoke_userv: pipe(c_stdin)");
    }
    if (pipe(c_stdout)!=0) {
	fatal_perror("userv_invoke_userv: pipe(c_stdout)");
    }
    st->txfd=c_stdin[1];
    st->rxfd=c_stdout[0];

    er=safe_malloc(sizeof(*r),"userv_invoke_userv: er");

    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,... */
    er->argv=safe_malloc(sizeof(*er->argv)*6,"userv_invoke_userv: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(er->argv);
    free(er);
    free(addrs);
    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, 2,
			  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 SE	29	netlink_deliver_fn *netlink_to_tunnel;
	30	uint32_t local_address;
	31	};
	32
	33	/* Generic SLIP mangling code */
	34
	35	static void slip_stuff(struct slip st, struct buffer_if buf, int fd)
	36	{
	37	uint8_t txbuf[DEFAULT_BUFSIZE];
	38	uint8_t *i;
1caa23ff	39	int32_t j=0;
042a8da9 SE	40
	41	BUF_ASSERT_USED(buf);
	42
d3fe100d	43	/* There's probably a much more efficient way of implementing this */
042a8da9 SE	44	txbuf[j++]=SLIP_END;
	45	for (i=buf->start; i<(buf->start+buf->size); i++) {
	46	switch (*i) {
	47	case SLIP_END:
	48	txbuf[j++]=SLIP_ESC;
	49	txbuf[j++]=SLIP_ESCEND;
	50	break;
	51	case SLIP_ESC:
	52	txbuf[j++]=SLIP_ESC;
	53	txbuf[j++]=SLIP_ESCESC;
	54	break;
	55	default:
	56	txbuf[j++]=*i;
	57	break;
	58	}
	59	if ((j+2)>DEFAULT_BUFSIZE) {
	60	if (write(fd,txbuf,j)<0) {
	61	fatal_perror("slip_stuff: write()");
	62	}
	63	j=0;
	64	}
	65	}
	66	txbuf[j++]=SLIP_END;
	67	if (write(fd,txbuf,j)<0) {
	68	fatal_perror("slip_stuff: write()");
	69	}
	70	BUF_FREE(buf);
	71	}
	72
	73	static void slip_unstuff(struct slip st, uint8_t buf, uint32_t l)
	74	{
	75	uint32_t i;
	76
042a8da9 SE	77	BUF_ASSERT_USED(st->buff);
042a8da9 SE	78	for (i=0; i<l; i++) {
e8a0782f ST	79	int outputchr;
	80	enum { OUTPUT_END = 256, OUTPUT_NOTHING = 257 };
	81
a28d65a5 IJ	82	if (!st->buff->size)
	83	buffer_init(st->buff,calculate_max_start_pad());
	84
042a8da9 SE	85	if (st->pending_esc) {
	86	st->pending_esc=False;
	87	switch(buf[i]) {
	88	case SLIP_ESCEND:
e8a0782f	89	outputchr=SLIP_END;
042a8da9 SE	90	break;
042a8da9 SE	91	case SLIP_ESCESC:
e8a0782f	92	outputchr=SLIP_ESC;
042a8da9 SE	93	break;
042a8da9 SE	94	default:
e8a0782f ST	95	if (!st->ignoring_packet) {
	96	Message(M_WARNING, "userv_afterpoll: bad SLIP escape"
	97	" character, dropping packet\n");
	98	}
	99	st->ignoring_packet=True;
	100	outputchr=OUTPUT_NOTHING;
	101	break;
042a8da9 SE	102	}
	103	} else {
	104	switch (buf[i]) {
	105	case SLIP_END:
e8a0782f	106	outputchr=OUTPUT_END;
042a8da9 SE	107	break;
	108	case SLIP_ESC:
	109	st->pending_esc=True;
e8a0782f	110	outputchr=OUTPUT_NOTHING;
042a8da9 SE	111	break;
042a8da9 SE	112	default:
e8a0782f	113	outputchr=buf[i];
042a8da9 SE	114	break;
	115	}
	116	}
e8a0782f ST	117
	118	if (st->ignoring_packet) {
	119	if (outputchr == OUTPUT_END) {
	120	st->ignoring_packet=False;
a28d65a5	121	st->buff->size=0;
e8a0782f ST	122	}
	123	} else {
	124	if (outputchr == OUTPUT_END) {
	125	if (st->buff->size>0) {
	126	st->netlink_to_tunnel(&st->nl,st->buff);
	127	BUF_ALLOC(st->buff,"userv_afterpoll");
	128	}
a28d65a5	129	st->buff->size=0;
e8a0782f ST	130	} else if (outputchr != OUTPUT_NOTHING) {
e8a0782f ST	131	if (st->buff->size < st->buff->len) {
993db2a6	132	buf_append_uint8(st->buff,outputchr);
e8a0782f ST	133	} else {
	134	Message(M_WARNING, "userv_afterpoll: dropping overlong"
	135	" SLIP packet\n");
	136	st->ignoring_packet=True;
	137	}
	138	}
	139	}
042a8da9 SE	140	}
	141	}
	142
	143	static void slip_init(struct slip st, struct cloc loc, dict_t dict,
fe5e9cc4	144	cstring_t name, netlink_deliver_fn *to_host)
042a8da9 SE	145	{
	146	st->netlink_to_tunnel=
	147	netlink_init(&st->nl,st,loc,dict,
	148	"netlink-userv-ipif",NULL,to_host);
	149	st->buff=find_cl_if(dict,"buffer",CL_BUFFER,True,"name",loc);
794f2398	150	st->local_address=string_item_to_ipaddr(
042a8da9 SE	151	dict_find_item(dict,"local-address", True, name, loc),"netlink");
	152	BUF_ALLOC(st->buff,"slip_init");
	153	st->pending_esc=False;
e8a0782f	154	st->ignoring_packet=False;
042a8da9 SE	155	}
042a8da9 SE	156
9d3a4132 SE	157	/* Connection to the kernel through userv-ipif */
	158
	159	struct userv {
042a8da9	160	struct slip slip;
9d3a4132 SE	161	int txfd; /* We transmit to userv */
9d3a4132 SE	162	int rxfd; /* We receive from userv */
fe5e9cc4 SE	163	cstring_t userv_path;
	164	cstring_t service_user;
	165	cstring_t service_name;
042a8da9 SE	166	pid_t pid;
042a8da9 SE	167	bool_t expecting_userv_exit;
9d3a4132 SE	168	};
	169
	170	static int userv_beforepoll(void sst, struct pollfd fds, int *nfds_io,
90a39563	171	int *timeout_io)
9d3a4132 SE	172	{
9d3a4132 SE	173	struct userv *st=sst;
042a8da9 SE	174
	175	if (st->rxfd!=-1) {
	176	*nfds_io=2;
	177	fds[0].fd=st->txfd;
fe5e9cc4	178	fds[0].events=0; /* Might want to pick up POLLOUT sometime */
042a8da9	179	fds[1].fd=st->rxfd;
fe5e9cc4	180	fds[1].events=POLLIN;
042a8da9 SE	181	} else {
	182	*nfds_io=0;
	183	}
9d3a4132 SE	184	return 0;
	185	}
	186
90a39563	187	static void userv_afterpoll(void sst, struct pollfd fds, int nfds)
9d3a4132 SE	188	{
	189	struct userv *st=sst;
	190	uint8_t rxbuf[DEFAULT_BUFSIZE];
042a8da9 SE	191	int l;
	192
	193	if (nfds==0) return;
9d3a4132 SE	194
9d3a4132 SE	195	if (fds[1].revents&POLLERR) {
469fd1d9	196	Message(M_ERR,"%s: userv_afterpoll: POLLERR!\n",st->slip.nl.name);
9d3a4132 SE	197	}
	198	if (fds[1].revents&POLLIN) {
	199	l=read(st->rxfd,rxbuf,DEFAULT_BUFSIZE);
	200	if (l<0) {
042a8da9 SE	201	if (errno!=EINTR)
	202	fatal_perror("%s: userv_afterpoll: read(rxfd)",
	203	st->slip.nl.name);
	204	} else if (l==0) {
4f5e39ec	205	fatal("%s: userv_afterpoll: read(rxfd)=0; userv gone away?",
042a8da9 SE	206	st->slip.nl.name);
042a8da9 SE	207	} else slip_unstuff(&st->slip,rxbuf,l);
9d3a4132 SE	208	}
	209	}
	210
	211	/* Send buf to the kernel. Free buf before returning. */
469fd1d9	212	static void userv_deliver_to_kernel(void sst, struct buffer_if buf)
9d3a4132 SE	213	{
9d3a4132 SE	214	struct userv *st=sst;
9d3a4132	215
042a8da9 SE	216	slip_stuff(&st->slip,buf,st->txfd);
042a8da9 SE	217	}
9d3a4132	218
042a8da9 SE	219	static void userv_userv_callback(void *sst, pid_t pid, int status)
	220	{
	221	struct userv *st=sst;
	222
	223	if (pid!=st->pid) {
	224	Message(M_WARNING,"userv_callback called unexpectedly with pid %d "
	225	"(expected %d)\n",pid,st->pid);
	226	return;
9d3a4132	227	}
042a8da9 SE	228	if (!st->expecting_userv_exit) {
042a8da9 SE	229	if (WIFEXITED(status)) {
4f5e39ec	230	fatal("%s: userv exited unexpectedly with status %d",
042a8da9 SE	231	st->slip.nl.name,WEXITSTATUS(status));
042a8da9 SE	232	} else if (WIFSIGNALED(status)) {
4f5e39ec	233	fatal("%s: userv exited unexpectedly: uncaught signal %d",
042a8da9 SE	234	st->slip.nl.name,WTERMSIG(status));
042a8da9 SE	235	} else {
779837e1 IJ	236	fatal("%s: userv stopped unexpectedly",
779837e1 IJ	237	st->slip.nl.name);
042a8da9	238	}
9d3a4132	239	}
042a8da9 SE	240	Message(M_WARNING,"%s: userv subprocess died with status %d\n",
	241	st->slip.nl.name,WEXITSTATUS(status));
	242	st->pid=0;
9d3a4132 SE	243	}
9d3a4132 SE	244
042a8da9	245	struct userv_entry_rec {
fe5e9cc4 SE	246	cstring_t path;
fe5e9cc4 SE	247	const char **argv;
469fd1d9 SE	248	int in;
469fd1d9 SE	249	int out;
042a8da9 SE	250	/* XXX perhaps we should collect and log stderr? */
	251	};
	252
	253	static void userv_entry(void *sst)
9d3a4132	254	{
042a8da9 SE	255	struct userv_entry_rec *st=sst;
042a8da9 SE	256
469fd1d9 SE	257	dup2(st->in,0);
469fd1d9 SE	258	dup2(st->out,1);
042a8da9 SE	259
	260	/* XXX close all other fds */
	261	setsid();
fe5e9cc4 SE	262	/* XXX We really should strdup() all of argv[] but because we'll just
	263	exit anyway if execvp() fails it doesn't seem worth bothering. */
	264	execvp(st->path,(char const)st->argv);
042a8da9 SE	265	perror("userv-entry: execvp()");
	266	exit(1);
	267	}
	268
	269	static void userv_invoke_userv(struct userv *st)
	270	{
	271	struct userv_entry_rec *er;
9d3a4132 SE	272	int c_stdin[2];
	273	int c_stdout[2];
	274	string_t addrs;
	275	string_t nets;
	276	string_t s;
d3fe100d SE	277	struct netlink_client *r;
d3fe100d SE	278	struct ipset *allnets;
794f2398	279	struct subnet_list *snets;
4f5e39ec	280	int i, nread;
042a8da9 SE	281	uint8_t confirm;
	282
	283	if (st->pid) {
4f5e39ec	284	fatal("userv_invoke_userv: already running");
042a8da9	285	}
9d3a4132 SE	286
	287	/* This is where we actually invoke userv - all the networks we'll
	288	be using should already have been registered. */
	289
042a8da9 SE	290	addrs=safe_malloc(512,"userv_invoke_userv:addrs");
	291	snprintf(addrs,512,"%s,%s,%d,slip",
	292	ipaddr_to_string(st->slip.local_address),
	293	ipaddr_to_string(st->slip.nl.secnet_address),st->slip.nl.mtu);
9d3a4132	294
d3fe100d SE	295	allnets=ipset_new();
d3fe100d SE	296	for (r=st->slip.nl.clients; r; r=r->next) {
f208b9a9 IJ	297	if (r->link_quality > LINK_QUALITY_UNUSED) {
	298	struct ipset *nan;
	299	r->kup=True;
	300	nan=ipset_union(allnets,r->networks);
	301	ipset_free(allnets);
	302	allnets=nan;
	303	}
9d3a4132	304	}
d3fe100d SE	305	snets=ipset_to_subnet_list(allnets);
d3fe100d SE	306	ipset_free(allnets);
794f2398 SE	307	nets=safe_malloc(20*snets->entries,"userv_invoke_userv:nets");
	308	*nets=0;
	309	for (i=0; i<snets->entries; i++) {
	310	s=subnet_to_string(snets->list[i]);
	311	strcat(nets,s);
	312	strcat(nets,",");
	313	free(s);
	314	}
9d3a4132	315	nets[strlen(nets)-1]=0;
794f2398	316	subnet_list_free(snets);
9d3a4132	317
042a8da9	318	Message(M_INFO,"%s: about to invoke: %s %s %s %s %s\n",st->slip.nl.name,
9d3a4132 SE	319	st->userv_path,st->service_user,st->service_name,addrs,nets);
9d3a4132 SE	320
042a8da9	321	st->slip.pending_esc=False;
9d3a4132 SE	322
	323	/* Invoke userv */
	324	if (pipe(c_stdin)!=0) {
042a8da9	325	fatal_perror("userv_invoke_userv: pipe(c_stdin)");
9d3a4132 SE	326	}
9d3a4132 SE	327	if (pipe(c_stdout)!=0) {
042a8da9	328	fatal_perror("userv_invoke_userv: pipe(c_stdout)");
9d3a4132 SE	329	}
	330	st->txfd=c_stdin[1];
	331	st->rxfd=c_stdout[0];
	332
042a8da9 SE	333	er=safe_malloc(sizeof(*r),"userv_invoke_userv: er");
042a8da9 SE	334
469fd1d9 SE	335	er->in=c_stdin[0];
469fd1d9 SE	336	er->out=c_stdout[1];
042a8da9 SE	337	/* The arguments are:
	338	userv
	339	service-user
	340	service-name
	341	local-addr,secnet-addr,mtu,protocol
	342	route1,route2,... */
	343	er->argv=safe_malloc(sizeof(er->argv)6,"userv_invoke_userv:argv");
	344	er->argv[0]=st->userv_path;
	345	er->argv[1]=st->service_user;
	346	er->argv[2]=st->service_name;
	347	er->argv[3]=addrs;
	348	er->argv[4]=nets;
	349	er->argv[5]=NULL;
	350	er->path=st->userv_path;
	351
	352	st->pid=makesubproc(userv_entry, userv_userv_callback,
	353	er, st, st->slip.nl.name);
469fd1d9 SE	354	close(er->in);
469fd1d9 SE	355	close(er->out);
042a8da9 SE	356	free(er->argv);
	357	free(er);
	358	free(addrs);
	359	free(nets);
	360	Message(M_INFO,"%s: userv-ipif pid is %d\n",st->slip.nl.name,st->pid);
	361	/* Read a single character from the pipe to confirm userv-ipif is
	362	running. If we get a SIGCHLD at this point then we'll get EINTR. */
4f5e39ec	363	if ((nread=read(st->rxfd,&confirm,1))!=1) {
042a8da9 SE	364	if (errno==EINTR) {
	365	Message(M_WARNING,"%s: read of confirmation byte was "
	366	"interrupted\n",st->slip.nl.name);
	367	} else {
4f5e39ec SE	368	if (nread<0) {
	369	fatal_perror("%s: error reading confirmation byte",
	370	st->slip.nl.name);
	371	} else {
	372	fatal("%s: unexpected EOF instead of confirmation byte"
	373	" - userv ipif failed?", st->slip.nl.name);
	374	}
042a8da9 SE	375	}
	376	} else {
	377	if (confirm!=SLIP_END) {
4f5e39ec	378	fatal("%s: bad confirmation byte %d from userv-ipif",
042a8da9 SE	379	st->slip.nl.name,confirm);
042a8da9 SE	380	}
9d3a4132	381	}
042a8da9 SE	382	}
	383
	384	static void userv_kill_userv(struct userv *st)
	385	{
	386	if (st->pid) {
	387	kill(-st->pid,SIGTERM);
	388	st->expecting_userv_exit=True;
	389	}
	390	}
	391
	392	static void userv_phase_hook(void *sst, uint32_t newphase)
	393	{
	394	struct userv *st=sst;
	395	/* We must wait until signal processing has started before forking
	396	userv */
	397	if (newphase==PHASE_RUN) {
	398	userv_invoke_userv(st);
	399	/* Register for poll() */
	400	register_for_poll(st, userv_beforepoll, userv_afterpoll, 2,
	401	st->slip.nl.name);
	402	}
	403	if (newphase==PHASE_SHUTDOWN) {
	404	userv_kill_userv(st);
9d3a4132	405	}
9d3a4132 SE	406	}
	407
	408	static list_t userv_apply(closure_t self, struct cloc loc, dict_t *context,
	409	list_t *args)
	410	{
	411	struct userv *st;
	412	item_t *item;
	413	dict_t *dict;
	414
	415	st=safe_malloc(sizeof(*st),"userv_apply");
	416
	417	/* First parameter must be a dict */
	418	item=list_elem(args,0);
	419	if (!item \|\| item->type!=t_dict)
	420	cfgfatal(loc,"userv-ipif","parameter must be a dictionary\n");
	421
	422	dict=item->data.dict;
	423
042a8da9 SE	424	slip_init(&st->slip,loc,dict,"netlink-userv-ipif",
042a8da9 SE	425	userv_deliver_to_kernel);
9d3a4132 SE	426
	427	st->userv_path=dict_read_string(dict,"userv-path",False,"userv-netlink",
	428	loc);
	429	st->service_user=dict_read_string(dict,"service-user",False,
	430	"userv-netlink",loc);
	431	st->service_name=dict_read_string(dict,"service-name",False,
	432	"userv-netlink",loc);
	433	if (!st->userv_path) st->userv_path="userv";
	434	if (!st->service_user) st->service_user="root";
	435	if (!st->service_name) st->service_name="ipif";
9d3a4132	436	st->rxfd=-1; st->txfd=-1;
042a8da9 SE	437	st->pid=0;
	438	st->expecting_userv_exit=False;
	439	add_hook(PHASE_RUN,userv_phase_hook,st);
	440	add_hook(PHASE_SHUTDOWN,userv_phase_hook,st);
9d3a4132	441
042a8da9	442	return new_closure(&st->slip.nl.cl);
9d3a4132 SE	443	}
9d3a4132 SE	444
9d3a4132 SE	445	void slip_module(dict_t *dict)
	446	{
	447	add_closure(dict,"userv-ipif",userv_apply);
9d3a4132	448	}