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. */
18 #define SLIP_ESCEND 220
19 #define SLIP_ESCESC 221
23 struct buffer_if *buff; /* We unstuff received packets into here
24 and send them to the netlink code. */
26 bool_t ignoring_packet; /* If this packet was corrupt or overlong,
27 we ignore everything up to the next END */
28 netlink_deliver_fn *netlink_to_tunnel;
29 uint32_t local_address;
32 /* Generic SLIP mangling code */
34 static void slip_stuff(struct slip *st, struct buffer_if *buf, int fd)
36 uint8_t txbuf[DEFAULT_BUFSIZE];
42 /* There's probably a much more efficient way of implementing this */
44 for (i=buf->start; i<(buf->start+buf->size); i++) {
48 txbuf[j++]=SLIP_ESCEND;
52 txbuf[j++]=SLIP_ESCESC;
58 if ((j+2)>DEFAULT_BUFSIZE) {
59 if (write(fd,txbuf,j)<0) {
60 fatal_perror("slip_stuff: write()");
66 if (write(fd,txbuf,j)<0) {
67 fatal_perror("slip_stuff: write()");
72 static void slip_unstuff(struct slip *st, uint8_t *buf, uint32_t l)
76 BUF_ASSERT_USED(st->buff);
79 enum { OUTPUT_END = 256, OUTPUT_NOTHING = 257 };
81 if (st->pending_esc) {
82 st->pending_esc=False;
91 if (!st->ignoring_packet) {
92 Message(M_WARNING, "userv_afterpoll: bad SLIP escape"
93 " character, dropping packet\n");
95 st->ignoring_packet=True;
96 outputchr=OUTPUT_NOTHING;
102 outputchr=OUTPUT_END;
105 st->pending_esc=True;
106 outputchr=OUTPUT_NOTHING;
114 if (st->ignoring_packet) {
115 if (outputchr == OUTPUT_END) {
116 st->ignoring_packet=False;
117 buffer_init(st->buff,st->nl.max_start_pad);
120 if (outputchr == OUTPUT_END) {
121 if (st->buff->size>0) {
122 st->netlink_to_tunnel(&st->nl,st->buff);
123 BUF_ALLOC(st->buff,"userv_afterpoll");
125 buffer_init(st->buff,st->nl.max_start_pad);
126 } else if (outputchr != OUTPUT_NOTHING) {
127 if (st->buff->size < st->buff->len) {
128 *(uint8_t *)buf_append(st->buff,1)=outputchr;
130 Message(M_WARNING, "userv_afterpoll: dropping overlong"
132 st->ignoring_packet=True;
139 static void slip_init(struct slip *st, struct cloc loc, dict_t *dict,
140 cstring_t name, netlink_deliver_fn *to_host)
142 st->netlink_to_tunnel=
143 netlink_init(&st->nl,st,loc,dict,
144 "netlink-userv-ipif",NULL,to_host);
145 st->buff=find_cl_if(dict,"buffer",CL_BUFFER,True,"name",loc);
146 st->local_address=string_item_to_ipaddr(
147 dict_find_item(dict,"local-address", True, name, loc),"netlink");
148 BUF_ALLOC(st->buff,"slip_init");
149 st->pending_esc=False;
150 st->ignoring_packet=False;
153 /* Connection to the kernel through userv-ipif */
157 int txfd; /* We transmit to userv */
158 int rxfd; /* We receive from userv */
159 cstring_t userv_path;
160 cstring_t service_user;
161 cstring_t service_name;
163 bool_t expecting_userv_exit;
166 static int userv_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
169 struct userv *st=sst;
174 fds[0].events=0; /* Might want to pick up POLLOUT sometime */
176 fds[1].events=POLLIN;
183 static void userv_afterpoll(void *sst, struct pollfd *fds, int nfds)
185 struct userv *st=sst;
186 uint8_t rxbuf[DEFAULT_BUFSIZE];
191 if (fds[1].revents&POLLERR) {
192 Message(M_ERR,"%s: userv_afterpoll: POLLERR!\n",st->slip.nl.name);
194 if (fds[1].revents&POLLIN) {
195 l=read(st->rxfd,rxbuf,DEFAULT_BUFSIZE);
198 fatal_perror("%s: userv_afterpoll: read(rxfd)",
201 fatal("%s: userv_afterpoll: read(rxfd)=0; userv gone away?",
203 } else slip_unstuff(&st->slip,rxbuf,l);
207 /* Send buf to the kernel. Free buf before returning. */
208 static void userv_deliver_to_kernel(void *sst, struct buffer_if *buf)
210 struct userv *st=sst;
212 slip_stuff(&st->slip,buf,st->txfd);
215 static void userv_userv_callback(void *sst, pid_t pid, int status)
217 struct userv *st=sst;
220 Message(M_WARNING,"userv_callback called unexpectedly with pid %d "
221 "(expected %d)\n",pid,st->pid);
224 if (!st->expecting_userv_exit) {
225 if (WIFEXITED(status)) {
226 fatal("%s: userv exited unexpectedly with status %d",
227 st->slip.nl.name,WEXITSTATUS(status));
228 } else if (WIFSIGNALED(status)) {
229 fatal("%s: userv exited unexpectedly: uncaught signal %d",
230 st->slip.nl.name,WTERMSIG(status));
232 fatal("%s: userv stopped unexpectedly");
235 Message(M_WARNING,"%s: userv subprocess died with status %d\n",
236 st->slip.nl.name,WEXITSTATUS(status));
240 struct userv_entry_rec {
245 /* XXX perhaps we should collect and log stderr? */
248 static void userv_entry(void *sst)
250 struct userv_entry_rec *st=sst;
255 /* XXX close all other fds */
257 /* XXX We really should strdup() all of argv[] but because we'll just
258 exit anyway if execvp() fails it doesn't seem worth bothering. */
259 execvp(st->path,(char *const*)st->argv);
260 perror("userv-entry: execvp()");
264 static void userv_invoke_userv(struct userv *st)
266 struct userv_entry_rec *er;
272 struct netlink_client *r;
273 struct ipset *allnets;
274 struct subnet_list *snets;
279 fatal("userv_invoke_userv: already running");
282 /* This is where we actually invoke userv - all the networks we'll
283 be using should already have been registered. */
285 addrs=safe_malloc(512,"userv_invoke_userv:addrs");
286 snprintf(addrs,512,"%s,%s,%d,slip",
287 ipaddr_to_string(st->slip.local_address),
288 ipaddr_to_string(st->slip.nl.secnet_address),st->slip.nl.mtu);
291 for (r=st->slip.nl.clients; r; r=r->next) {
292 if (r->link_quality > LINK_QUALITY_UNUSED) {
295 nan=ipset_union(allnets,r->networks);
300 snets=ipset_to_subnet_list(allnets);
302 nets=safe_malloc(20*snets->entries,"userv_invoke_userv:nets");
304 for (i=0; i<snets->entries; i++) {
305 s=subnet_to_string(snets->list[i]);
310 nets[strlen(nets)-1]=0;
311 subnet_list_free(snets);
313 Message(M_INFO,"%s: about to invoke: %s %s %s %s %s\n",st->slip.nl.name,
314 st->userv_path,st->service_user,st->service_name,addrs,nets);
316 st->slip.pending_esc=False;
319 if (pipe(c_stdin)!=0) {
320 fatal_perror("userv_invoke_userv: pipe(c_stdin)");
322 if (pipe(c_stdout)!=0) {
323 fatal_perror("userv_invoke_userv: pipe(c_stdout)");
326 st->rxfd=c_stdout[0];
328 er=safe_malloc(sizeof(*r),"userv_invoke_userv: er");
332 /* The arguments are:
336 local-addr,secnet-addr,mtu,protocol
338 er->argv=safe_malloc(sizeof(*er->argv)*6,"userv_invoke_userv:argv");
339 er->argv[0]=st->userv_path;
340 er->argv[1]=st->service_user;
341 er->argv[2]=st->service_name;
345 er->path=st->userv_path;
347 st->pid=makesubproc(userv_entry, userv_userv_callback,
348 er, st, st->slip.nl.name);
355 Message(M_INFO,"%s: userv-ipif pid is %d\n",st->slip.nl.name,st->pid);
356 /* Read a single character from the pipe to confirm userv-ipif is
357 running. If we get a SIGCHLD at this point then we'll get EINTR. */
358 if ((nread=read(st->rxfd,&confirm,1))!=1) {
360 Message(M_WARNING,"%s: read of confirmation byte was "
361 "interrupted\n",st->slip.nl.name);
364 fatal_perror("%s: error reading confirmation byte",
367 fatal("%s: unexpected EOF instead of confirmation byte"
368 " - userv ipif failed?", st->slip.nl.name);
372 if (confirm!=SLIP_END) {
373 fatal("%s: bad confirmation byte %d from userv-ipif",
374 st->slip.nl.name,confirm);
379 static void userv_kill_userv(struct userv *st)
382 kill(-st->pid,SIGTERM);
383 st->expecting_userv_exit=True;
387 static void userv_phase_hook(void *sst, uint32_t newphase)
389 struct userv *st=sst;
390 /* We must wait until signal processing has started before forking
392 if (newphase==PHASE_RUN) {
393 userv_invoke_userv(st);
394 /* Register for poll() */
395 register_for_poll(st, userv_beforepoll, userv_afterpoll, 2,
398 if (newphase==PHASE_SHUTDOWN) {
399 userv_kill_userv(st);
403 static list_t *userv_apply(closure_t *self, struct cloc loc, dict_t *context,
410 st=safe_malloc(sizeof(*st),"userv_apply");
412 /* First parameter must be a dict */
413 item=list_elem(args,0);
414 if (!item || item->type!=t_dict)
415 cfgfatal(loc,"userv-ipif","parameter must be a dictionary\n");
417 dict=item->data.dict;
419 slip_init(&st->slip,loc,dict,"netlink-userv-ipif",
420 userv_deliver_to_kernel);
422 st->userv_path=dict_read_string(dict,"userv-path",False,"userv-netlink",
424 st->service_user=dict_read_string(dict,"service-user",False,
425 "userv-netlink",loc);
426 st->service_name=dict_read_string(dict,"service-name",False,
427 "userv-netlink",loc);
428 if (!st->userv_path) st->userv_path="userv";
429 if (!st->service_user) st->service_user="root";
430 if (!st->service_name) st->service_name="ipif";
431 st->rxfd=-1; st->txfd=-1;
433 st->expecting_userv_exit=False;
434 add_hook(PHASE_RUN,userv_phase_hook,st);
435 add_hook(PHASE_SHUTDOWN,userv_phase_hook,st);
437 return new_closure(&st->slip.nl.cl);
440 void slip_module(dict_t *dict)
442 add_closure(dict,"userv-ipif",userv_apply);