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. */
10 #include "unaligned.h"
19 #define SLIP_ESCEND 220
20 #define SLIP_ESCESC 221
24 struct buffer_if *buff; /* We unstuff received packets into here
25 and send them to the netlink code. */
27 bool_t ignoring_packet; /* If this packet was corrupt or overlong,
28 we ignore everything up to the next END */
29 netlink_deliver_fn *netlink_to_tunnel;
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 };
82 buffer_init(st->buff,calculate_max_start_pad());
84 if (st->pending_esc) {
85 st->pending_esc=False;
94 if (!st->ignoring_packet) {
95 Message(M_WARNING, "userv_afterpoll: bad SLIP escape"
96 " character, dropping packet\n");
98 st->ignoring_packet=True;
99 outputchr=OUTPUT_NOTHING;
105 outputchr=OUTPUT_END;
108 st->pending_esc=True;
109 outputchr=OUTPUT_NOTHING;
117 if (st->ignoring_packet) {
118 if (outputchr == OUTPUT_END) {
119 st->ignoring_packet=False;
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");
129 } else if (outputchr != OUTPUT_NOTHING) {
130 if (buf_remaining_space(st->buff)) {
131 buf_append_uint8(st->buff,outputchr);
133 Message(M_WARNING, "userv_afterpoll: dropping overlong"
135 st->ignoring_packet=True;
142 static void slip_init(struct slip *st, struct cloc loc, dict_t *dict,
143 cstring_t name, netlink_deliver_fn *to_host)
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);
149 BUF_ALLOC(st->buff,"slip_init");
150 st->pending_esc=False;
151 st->ignoring_packet=False;
154 /* Connection to the kernel through userv-ipif */
158 int txfd; /* We transmit to userv */
159 int rxfd; /* We receive from userv */
160 cstring_t userv_path;
161 cstring_t service_user;
162 cstring_t service_name;
164 bool_t expecting_userv_exit;
167 static int userv_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
170 struct userv *st=sst;
175 fds[0].events=0; /* Might want to pick up POLLOUT sometime */
177 fds[1].events=POLLIN;
184 static void userv_afterpoll(void *sst, struct pollfd *fds, int nfds)
186 struct userv *st=sst;
187 uint8_t rxbuf[DEFAULT_BUFSIZE];
192 if (fds[1].revents&POLLERR) {
193 Message(M_ERR,"%s: userv_afterpoll: POLLERR!\n",st->slip.nl.name);
195 if (fds[1].revents&POLLIN) {
196 l=read(st->rxfd,rxbuf,DEFAULT_BUFSIZE);
199 fatal_perror("%s: userv_afterpoll: read(rxfd)",
202 fatal("%s: userv_afterpoll: read(rxfd)=0; userv gone away?",
204 } else slip_unstuff(&st->slip,rxbuf,l);
208 /* Send buf to the kernel. Free buf before returning. */
209 static void userv_deliver_to_kernel(void *sst, struct buffer_if *buf)
211 struct userv *st=sst;
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);
221 slip_stuff(&st->slip,buf,st->txfd);
224 static void userv_userv_callback(void *sst, pid_t pid, int status)
226 struct userv *st=sst;
229 Message(M_WARNING,"userv_callback called unexpectedly with pid %d "
230 "(expected %d)\n",pid,st->pid);
233 if (!st->expecting_userv_exit) {
234 if (WIFEXITED(status)) {
235 fatal("%s: userv exited unexpectedly with status %d",
236 st->slip.nl.name,WEXITSTATUS(status));
237 } else if (WIFSIGNALED(status)) {
238 fatal("%s: userv exited unexpectedly: uncaught signal %d",
239 st->slip.nl.name,WTERMSIG(status));
241 fatal("%s: userv stopped unexpectedly",
245 Message(M_WARNING,"%s: userv subprocess died with status %d\n",
246 st->slip.nl.name,WEXITSTATUS(status));
250 struct userv_entry_rec {
255 /* XXX perhaps we should collect and log stderr? */
258 static void userv_entry(void *sst)
260 struct userv_entry_rec *st=sst;
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);
269 perror("userv-entry: execvp()");
273 static void userv_invoke_userv(struct userv *st)
275 struct userv_entry_rec er[1];
280 struct netlink_client *r;
281 struct ipset *allnets;
282 struct subnet_list *snets;
287 fatal("userv_invoke_userv: already running");
290 /* This is where we actually invoke userv - all the networks we'll
291 be using should already have been registered. */
294 snprintf(addrs,sizeof(addrs),"%s,%s,%d,slip",
295 ipaddr_to_string(st->slip.nl.local_address),
296 ipaddr_to_string(st->slip.nl.secnet_address),st->slip.nl.mtu);
299 for (r=st->slip.nl.clients; r; r=r->next) {
300 if (r->link_quality > LINK_QUALITY_UNUSED) {
303 nan=ipset_union(allnets,r->networks);
308 snets=ipset_to_subnet_list(allnets);
310 nets=safe_malloc(20*snets->entries,"userv_invoke_userv:nets");
312 for (i=0; i<snets->entries; i++) {
313 s=subnet_to_string(snets->list[i]);
317 nets[strlen(nets)-1]=0;
318 subnet_list_free(snets);
320 Message(M_INFO,"%s: about to invoke: %s %s %s %s %s\n",st->slip.nl.name,
321 st->userv_path,st->service_user,st->service_name,addrs,nets);
323 st->slip.pending_esc=False;
326 pipe_cloexec(c_stdin);
327 pipe_cloexec(c_stdout);
329 st->rxfd=c_stdout[0];
333 /* The arguments are:
337 local-addr,secnet-addr,mtu,protocol
339 const char *er_argv[6];
341 er->argv[0]=st->userv_path;
342 er->argv[1]=st->service_user;
343 er->argv[2]=st->service_name;
347 er->path=st->userv_path;
349 st->pid=makesubproc(userv_entry, userv_userv_callback,
350 er, st, st->slip.nl.name);
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. */
357 if ((nread=read(st->rxfd,&confirm,1))!=1) {
359 Message(M_WARNING,"%s: read of confirmation byte was "
360 "interrupted\n",st->slip.nl.name);
363 fatal_perror("%s: error reading confirmation byte",
366 fatal("%s: unexpected EOF instead of confirmation byte"
367 " - userv ipif failed?", st->slip.nl.name);
371 if (confirm!=SLIP_END) {
372 fatal("%s: bad confirmation byte %d from userv-ipif",
373 st->slip.nl.name,confirm);
378 static void userv_kill_userv(struct userv *st)
381 kill(-st->pid,SIGTERM);
382 st->expecting_userv_exit=True;
386 static void userv_phase_hook(void *sst, uint32_t newphase)
388 struct userv *st=sst;
389 /* We must wait until signal processing has started before forking
391 if (newphase==PHASE_RUN) {
392 userv_invoke_userv(st);
393 /* Register for poll() */
394 register_for_poll(st, userv_beforepoll, userv_afterpoll, 2,
397 if (newphase==PHASE_SHUTDOWN) {
398 userv_kill_userv(st);
402 static list_t *userv_apply(closure_t *self, struct cloc loc, dict_t *context,
409 st=safe_malloc(sizeof(*st),"userv_apply");
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");
416 dict=item->data.dict;
418 slip_init(&st->slip,loc,dict,"netlink-userv-ipif",
419 userv_deliver_to_kernel);
421 st->userv_path=dict_read_string(dict,"userv-path",False,"userv-netlink",
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";
430 st->rxfd=-1; st->txfd=-1;
432 st->expecting_userv_exit=False;
433 add_hook(PHASE_RUN,userv_phase_hook,st);
434 add_hook(PHASE_SHUTDOWN,userv_phase_hook,st);
436 return new_closure(&st->slip.nl.cl);
439 void slip_module(dict_t *dict)
441 add_closure(dict,"userv-ipif",userv_apply);