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;
30 uint32_t local_address;
33 /* Generic SLIP mangling code */
35 static void slip_stuff(struct slip *st, struct buffer_if *buf, int fd)
37 uint8_t txbuf[DEFAULT_BUFSIZE];
43 /* There's probably a much more efficient way of implementing this */
45 for (i=buf->start; i<(buf->start+buf->size); i++) {
49 txbuf[j++]=SLIP_ESCEND;
53 txbuf[j++]=SLIP_ESCESC;
59 if ((j+2)>DEFAULT_BUFSIZE) {
60 if (write(fd,txbuf,j)<0) {
61 fatal_perror("slip_stuff: write()");
67 if (write(fd,txbuf,j)<0) {
68 fatal_perror("slip_stuff: write()");
73 static void slip_unstuff(struct slip *st, uint8_t *buf, uint32_t l)
77 BUF_ASSERT_USED(st->buff);
80 enum { OUTPUT_END = 256, OUTPUT_NOTHING = 257 };
83 buffer_init(st->buff,calculate_max_start_pad());
85 if (st->pending_esc) {
86 st->pending_esc=False;
95 if (!st->ignoring_packet) {
96 Message(M_WARNING, "userv_afterpoll: bad SLIP escape"
97 " character, dropping packet\n");
99 st->ignoring_packet=True;
100 outputchr=OUTPUT_NOTHING;
106 outputchr=OUTPUT_END;
109 st->pending_esc=True;
110 outputchr=OUTPUT_NOTHING;
118 if (st->ignoring_packet) {
119 if (outputchr == OUTPUT_END) {
120 st->ignoring_packet=False;
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");
130 } else if (outputchr != OUTPUT_NOTHING) {
131 if (st->buff->size < st->buff->len) {
132 buf_append_uint8(st->buff,outputchr);
134 Message(M_WARNING, "userv_afterpoll: dropping overlong"
136 st->ignoring_packet=True;
143 static void slip_init(struct slip *st, struct cloc loc, dict_t *dict,
144 cstring_t name, netlink_deliver_fn *to_host)
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);
150 st->local_address=string_item_to_ipaddr(
151 dict_find_item(dict,"local-address", True, name, loc),"netlink");
152 BUF_ALLOC(st->buff,"slip_init");
153 st->pending_esc=False;
154 st->ignoring_packet=False;
157 /* Connection to the kernel through userv-ipif */
161 int txfd; /* We transmit to userv */
162 int rxfd; /* We receive from userv */
163 cstring_t userv_path;
164 cstring_t service_user;
165 cstring_t service_name;
167 bool_t expecting_userv_exit;
170 static int userv_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
173 struct userv *st=sst;
178 fds[0].events=0; /* Might want to pick up POLLOUT sometime */
180 fds[1].events=POLLIN;
187 static void userv_afterpoll(void *sst, struct pollfd *fds, int nfds)
189 struct userv *st=sst;
190 uint8_t rxbuf[DEFAULT_BUFSIZE];
195 if (fds[1].revents&POLLERR) {
196 Message(M_ERR,"%s: userv_afterpoll: POLLERR!\n",st->slip.nl.name);
198 if (fds[1].revents&POLLIN) {
199 l=read(st->rxfd,rxbuf,DEFAULT_BUFSIZE);
202 fatal_perror("%s: userv_afterpoll: read(rxfd)",
205 fatal("%s: userv_afterpoll: read(rxfd)=0; userv gone away?",
207 } else slip_unstuff(&st->slip,rxbuf,l);
211 /* Send buf to the kernel. Free buf before returning. */
212 static void userv_deliver_to_kernel(void *sst, struct buffer_if *buf)
214 struct userv *st=sst;
216 if (buf->size > st->slip.nl.mtu) {
217 Message(M_ERR,"%s: packet of size %"PRIu32" exceeds mtu %"PRIu32":"
218 " cannot be injected into kernel, dropped\n",
219 st->slip.nl.name, buf->size, st->slip.nl.mtu);
224 slip_stuff(&st->slip,buf,st->txfd);
227 static void userv_userv_callback(void *sst, pid_t pid, int status)
229 struct userv *st=sst;
232 Message(M_WARNING,"userv_callback called unexpectedly with pid %d "
233 "(expected %d)\n",pid,st->pid);
236 if (!st->expecting_userv_exit) {
237 if (WIFEXITED(status)) {
238 fatal("%s: userv exited unexpectedly with status %d",
239 st->slip.nl.name,WEXITSTATUS(status));
240 } else if (WIFSIGNALED(status)) {
241 fatal("%s: userv exited unexpectedly: uncaught signal %d",
242 st->slip.nl.name,WTERMSIG(status));
244 fatal("%s: userv stopped unexpectedly",
248 Message(M_WARNING,"%s: userv subprocess died with status %d\n",
249 st->slip.nl.name,WEXITSTATUS(status));
253 struct userv_entry_rec {
258 /* XXX perhaps we should collect and log stderr? */
261 static void userv_entry(void *sst)
263 struct userv_entry_rec *st=sst;
268 /* XXX close all other fds */
270 /* XXX We really should strdup() all of argv[] but because we'll just
271 exit anyway if execvp() fails it doesn't seem worth bothering. */
272 execvp(st->path,(char *const*)st->argv);
273 perror("userv-entry: execvp()");
277 static void userv_invoke_userv(struct userv *st)
279 struct userv_entry_rec *er;
285 struct netlink_client *r;
286 struct ipset *allnets;
287 struct subnet_list *snets;
292 fatal("userv_invoke_userv: already running");
295 /* This is where we actually invoke userv - all the networks we'll
296 be using should already have been registered. */
298 addrs=safe_malloc(512,"userv_invoke_userv:addrs");
299 snprintf(addrs,512,"%s,%s,%d,slip",
300 ipaddr_to_string(st->slip.local_address),
301 ipaddr_to_string(st->slip.nl.secnet_address),st->slip.nl.mtu);
304 for (r=st->slip.nl.clients; r; r=r->next) {
305 if (r->link_quality > LINK_QUALITY_UNUSED) {
308 nan=ipset_union(allnets,r->networks);
313 snets=ipset_to_subnet_list(allnets);
315 nets=safe_malloc(20*snets->entries,"userv_invoke_userv:nets");
317 for (i=0; i<snets->entries; i++) {
318 s=subnet_to_string(snets->list[i]);
323 nets[strlen(nets)-1]=0;
324 subnet_list_free(snets);
326 Message(M_INFO,"%s: about to invoke: %s %s %s %s %s\n",st->slip.nl.name,
327 st->userv_path,st->service_user,st->service_name,addrs,nets);
329 st->slip.pending_esc=False;
332 if (pipe(c_stdin)!=0) {
333 fatal_perror("userv_invoke_userv: pipe(c_stdin)");
335 if (pipe(c_stdout)!=0) {
336 fatal_perror("userv_invoke_userv: pipe(c_stdout)");
339 st->rxfd=c_stdout[0];
341 er=safe_malloc(sizeof(*r),"userv_invoke_userv: er");
345 /* The arguments are:
349 local-addr,secnet-addr,mtu,protocol
351 er->argv=safe_malloc(sizeof(*er->argv)*6,"userv_invoke_userv:argv");
352 er->argv[0]=st->userv_path;
353 er->argv[1]=st->service_user;
354 er->argv[2]=st->service_name;
358 er->path=st->userv_path;
360 st->pid=makesubproc(userv_entry, userv_userv_callback,
361 er, st, st->slip.nl.name);
368 Message(M_INFO,"%s: userv-ipif pid is %d\n",st->slip.nl.name,st->pid);
369 /* Read a single character from the pipe to confirm userv-ipif is
370 running. If we get a SIGCHLD at this point then we'll get EINTR. */
371 if ((nread=read(st->rxfd,&confirm,1))!=1) {
373 Message(M_WARNING,"%s: read of confirmation byte was "
374 "interrupted\n",st->slip.nl.name);
377 fatal_perror("%s: error reading confirmation byte",
380 fatal("%s: unexpected EOF instead of confirmation byte"
381 " - userv ipif failed?", st->slip.nl.name);
385 if (confirm!=SLIP_END) {
386 fatal("%s: bad confirmation byte %d from userv-ipif",
387 st->slip.nl.name,confirm);
392 static void userv_kill_userv(struct userv *st)
395 kill(-st->pid,SIGTERM);
396 st->expecting_userv_exit=True;
400 static void userv_phase_hook(void *sst, uint32_t newphase)
402 struct userv *st=sst;
403 /* We must wait until signal processing has started before forking
405 if (newphase==PHASE_RUN) {
406 userv_invoke_userv(st);
407 /* Register for poll() */
408 register_for_poll(st, userv_beforepoll, userv_afterpoll, 2,
411 if (newphase==PHASE_SHUTDOWN) {
412 userv_kill_userv(st);
416 static list_t *userv_apply(closure_t *self, struct cloc loc, dict_t *context,
423 st=safe_malloc(sizeof(*st),"userv_apply");
425 /* First parameter must be a dict */
426 item=list_elem(args,0);
427 if (!item || item->type!=t_dict)
428 cfgfatal(loc,"userv-ipif","parameter must be a dictionary\n");
430 dict=item->data.dict;
432 slip_init(&st->slip,loc,dict,"netlink-userv-ipif",
433 userv_deliver_to_kernel);
435 st->userv_path=dict_read_string(dict,"userv-path",False,"userv-netlink",
437 st->service_user=dict_read_string(dict,"service-user",False,
438 "userv-netlink",loc);
439 st->service_name=dict_read_string(dict,"service-name",False,
440 "userv-netlink",loc);
441 if (!st->userv_path) st->userv_path="userv";
442 if (!st->service_user) st->service_user="root";
443 if (!st->service_name) st->service_name="ipif";
444 st->rxfd=-1; st->txfd=-1;
446 st->expecting_userv_exit=False;
447 add_hook(PHASE_RUN,userv_phase_hook,st);
448 add_hook(PHASE_SHUTDOWN,userv_phase_hook,st);
450 return new_closure(&st->slip.nl.cl);
453 void slip_module(dict_t *dict)
455 add_closure(dict,"userv-ipif",userv_apply);