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 slip_stuff(&st->slip,buf,st->txfd);
219 static void userv_userv_callback(void *sst, pid_t pid, int status)
221 struct userv *st=sst;
224 Message(M_WARNING,"userv_callback called unexpectedly with pid %d "
225 "(expected %d)\n",pid,st->pid);
228 if (!st->expecting_userv_exit) {
229 if (WIFEXITED(status)) {
230 fatal("%s: userv exited unexpectedly with status %d",
231 st->slip.nl.name,WEXITSTATUS(status));
232 } else if (WIFSIGNALED(status)) {
233 fatal("%s: userv exited unexpectedly: uncaught signal %d",
234 st->slip.nl.name,WTERMSIG(status));
236 fatal("%s: userv stopped unexpectedly",
240 Message(M_WARNING,"%s: userv subprocess died with status %d\n",
241 st->slip.nl.name,WEXITSTATUS(status));
245 struct userv_entry_rec {
250 /* XXX perhaps we should collect and log stderr? */
253 static void userv_entry(void *sst)
255 struct userv_entry_rec *st=sst;
260 /* XXX close all other fds */
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);
265 perror("userv-entry: execvp()");
269 static void userv_invoke_userv(struct userv *st)
271 struct userv_entry_rec *er;
277 struct netlink_client *r;
278 struct ipset *allnets;
279 struct subnet_list *snets;
284 fatal("userv_invoke_userv: already running");
287 /* This is where we actually invoke userv - all the networks we'll
288 be using should already have been registered. */
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);
296 for (r=st->slip.nl.clients; r; r=r->next) {
297 if (r->link_quality > LINK_QUALITY_UNUSED) {
300 nan=ipset_union(allnets,r->networks);
305 snets=ipset_to_subnet_list(allnets);
307 nets=safe_malloc(20*snets->entries,"userv_invoke_userv:nets");
309 for (i=0; i<snets->entries; i++) {
310 s=subnet_to_string(snets->list[i]);
315 nets[strlen(nets)-1]=0;
316 subnet_list_free(snets);
318 Message(M_INFO,"%s: about to invoke: %s %s %s %s %s\n",st->slip.nl.name,
319 st->userv_path,st->service_user,st->service_name,addrs,nets);
321 st->slip.pending_esc=False;
324 if (pipe(c_stdin)!=0) {
325 fatal_perror("userv_invoke_userv: pipe(c_stdin)");
327 if (pipe(c_stdout)!=0) {
328 fatal_perror("userv_invoke_userv: pipe(c_stdout)");
331 st->rxfd=c_stdout[0];
333 er=safe_malloc(sizeof(*r),"userv_invoke_userv: er");
337 /* The arguments are:
341 local-addr,secnet-addr,mtu,protocol
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;
350 er->path=st->userv_path;
352 st->pid=makesubproc(userv_entry, userv_userv_callback,
353 er, st, st->slip.nl.name);
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. */
363 if ((nread=read(st->rxfd,&confirm,1))!=1) {
365 Message(M_WARNING,"%s: read of confirmation byte was "
366 "interrupted\n",st->slip.nl.name);
369 fatal_perror("%s: error reading confirmation byte",
372 fatal("%s: unexpected EOF instead of confirmation byte"
373 " - userv ipif failed?", st->slip.nl.name);
377 if (confirm!=SLIP_END) {
378 fatal("%s: bad confirmation byte %d from userv-ipif",
379 st->slip.nl.name,confirm);
384 static void userv_kill_userv(struct userv *st)
387 kill(-st->pid,SIGTERM);
388 st->expecting_userv_exit=True;
392 static void userv_phase_hook(void *sst, uint32_t newphase)
394 struct userv *st=sst;
395 /* We must wait until signal processing has started before forking
397 if (newphase==PHASE_RUN) {
398 userv_invoke_userv(st);
399 /* Register for poll() */
400 register_for_poll(st, userv_beforepoll, userv_afterpoll, 2,
403 if (newphase==PHASE_SHUTDOWN) {
404 userv_kill_userv(st);
408 static list_t *userv_apply(closure_t *self, struct cloc loc, dict_t *context,
415 st=safe_malloc(sizeof(*st),"userv_apply");
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");
422 dict=item->data.dict;
424 slip_init(&st->slip,loc,dict,"netlink-userv-ipif",
425 userv_deliver_to_kernel);
427 st->userv_path=dict_read_string(dict,"userv-path",False,"userv-netlink",
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";
436 st->rxfd=-1; st->txfd=-1;
438 st->expecting_userv_exit=False;
439 add_hook(PHASE_RUN,userv_phase_hook,st);
440 add_hook(PHASE_SHUTDOWN,userv_phase_hook,st);
442 return new_closure(&st->slip.nl.cl);
445 void slip_module(dict_t *dict)
447 add_closure(dict,"userv-ipif",userv_apply);