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" |
9d3a4132 SE |
10 | #include <stdio.h> |
11 | #include <string.h> | |
12 | #include <unistd.h> | |
042a8da9 SE |
13 | #include <errno.h> |
14 | #include <fcntl.h> | |
9d3a4132 SE |
15 | |
16 | #define SLIP_END 192 | |
17 | #define SLIP_ESC 219 | |
18 | #define SLIP_ESCEND 220 | |
19 | #define SLIP_ESCESC 221 | |
20 | ||
042a8da9 SE |
21 | struct slip { |
22 | struct netlink nl; | |
23 | struct buffer_if *buff; /* We unstuff received packets into here | |
24 | and send them to the netlink code. */ | |
25 | bool_t pending_esc; | |
e8a0782f ST |
26 | bool_t ignoring_packet; /* If this packet was corrupt or overlong, |
27 | we ignore everything up to the next END */ | |
042a8da9 SE |
28 | netlink_deliver_fn *netlink_to_tunnel; |
29 | uint32_t local_address; | |
30 | }; | |
31 | ||
32 | /* Generic SLIP mangling code */ | |
33 | ||
34 | static void slip_stuff(struct slip *st, struct buffer_if *buf, int fd) | |
35 | { | |
36 | uint8_t txbuf[DEFAULT_BUFSIZE]; | |
37 | uint8_t *i; | |
1caa23ff | 38 | int32_t j=0; |
042a8da9 SE |
39 | |
40 | BUF_ASSERT_USED(buf); | |
41 | ||
d3fe100d | 42 | /* There's probably a much more efficient way of implementing this */ |
042a8da9 SE |
43 | txbuf[j++]=SLIP_END; |
44 | for (i=buf->start; i<(buf->start+buf->size); i++) { | |
45 | switch (*i) { | |
46 | case SLIP_END: | |
47 | txbuf[j++]=SLIP_ESC; | |
48 | txbuf[j++]=SLIP_ESCEND; | |
49 | break; | |
50 | case SLIP_ESC: | |
51 | txbuf[j++]=SLIP_ESC; | |
52 | txbuf[j++]=SLIP_ESCESC; | |
53 | break; | |
54 | default: | |
55 | txbuf[j++]=*i; | |
56 | break; | |
57 | } | |
58 | if ((j+2)>DEFAULT_BUFSIZE) { | |
59 | if (write(fd,txbuf,j)<0) { | |
60 | fatal_perror("slip_stuff: write()"); | |
61 | } | |
62 | j=0; | |
63 | } | |
64 | } | |
65 | txbuf[j++]=SLIP_END; | |
66 | if (write(fd,txbuf,j)<0) { | |
67 | fatal_perror("slip_stuff: write()"); | |
68 | } | |
69 | BUF_FREE(buf); | |
70 | } | |
71 | ||
72 | static void slip_unstuff(struct slip *st, uint8_t *buf, uint32_t l) | |
73 | { | |
74 | uint32_t i; | |
75 | ||
042a8da9 SE |
76 | BUF_ASSERT_USED(st->buff); |
77 | for (i=0; i<l; i++) { | |
e8a0782f ST |
78 | int outputchr; |
79 | enum { OUTPUT_END = 256, OUTPUT_NOTHING = 257 }; | |
80 | ||
042a8da9 SE |
81 | if (st->pending_esc) { |
82 | st->pending_esc=False; | |
83 | switch(buf[i]) { | |
84 | case SLIP_ESCEND: | |
e8a0782f | 85 | outputchr=SLIP_END; |
042a8da9 SE |
86 | break; |
87 | case SLIP_ESCESC: | |
e8a0782f | 88 | outputchr=SLIP_ESC; |
042a8da9 SE |
89 | break; |
90 | default: | |
e8a0782f ST |
91 | if (!st->ignoring_packet) { |
92 | Message(M_WARNING, "userv_afterpoll: bad SLIP escape" | |
93 | " character, dropping packet\n"); | |
94 | } | |
95 | st->ignoring_packet=True; | |
96 | outputchr=OUTPUT_NOTHING; | |
97 | break; | |
042a8da9 SE |
98 | } |
99 | } else { | |
100 | switch (buf[i]) { | |
101 | case SLIP_END: | |
e8a0782f | 102 | outputchr=OUTPUT_END; |
042a8da9 SE |
103 | break; |
104 | case SLIP_ESC: | |
105 | st->pending_esc=True; | |
e8a0782f | 106 | outputchr=OUTPUT_NOTHING; |
042a8da9 SE |
107 | break; |
108 | default: | |
e8a0782f | 109 | outputchr=buf[i]; |
042a8da9 SE |
110 | break; |
111 | } | |
112 | } | |
e8a0782f ST |
113 | |
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); | |
118 | } | |
119 | } else { | |
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"); | |
124 | } | |
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; | |
129 | } else { | |
130 | Message(M_WARNING, "userv_afterpoll: dropping overlong" | |
131 | " SLIP packet\n"); | |
132 | st->ignoring_packet=True; | |
133 | } | |
134 | } | |
135 | } | |
042a8da9 SE |
136 | } |
137 | } | |
138 | ||
139 | static void slip_init(struct slip *st, struct cloc loc, dict_t *dict, | |
fe5e9cc4 | 140 | cstring_t name, netlink_deliver_fn *to_host) |
042a8da9 SE |
141 | { |
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); | |
794f2398 | 146 | st->local_address=string_item_to_ipaddr( |
042a8da9 SE |
147 | dict_find_item(dict,"local-address", True, name, loc),"netlink"); |
148 | BUF_ALLOC(st->buff,"slip_init"); | |
149 | st->pending_esc=False; | |
e8a0782f | 150 | st->ignoring_packet=False; |
042a8da9 SE |
151 | } |
152 | ||
9d3a4132 SE |
153 | /* Connection to the kernel through userv-ipif */ |
154 | ||
155 | struct userv { | |
042a8da9 | 156 | struct slip slip; |
9d3a4132 SE |
157 | int txfd; /* We transmit to userv */ |
158 | int rxfd; /* We receive from userv */ | |
fe5e9cc4 SE |
159 | cstring_t userv_path; |
160 | cstring_t service_user; | |
161 | cstring_t service_name; | |
042a8da9 SE |
162 | pid_t pid; |
163 | bool_t expecting_userv_exit; | |
9d3a4132 SE |
164 | }; |
165 | ||
166 | static int userv_beforepoll(void *sst, struct pollfd *fds, int *nfds_io, | |
90a39563 | 167 | int *timeout_io) |
9d3a4132 SE |
168 | { |
169 | struct userv *st=sst; | |
042a8da9 SE |
170 | |
171 | if (st->rxfd!=-1) { | |
172 | *nfds_io=2; | |
173 | fds[0].fd=st->txfd; | |
fe5e9cc4 | 174 | fds[0].events=0; /* Might want to pick up POLLOUT sometime */ |
042a8da9 | 175 | fds[1].fd=st->rxfd; |
fe5e9cc4 | 176 | fds[1].events=POLLIN; |
042a8da9 SE |
177 | } else { |
178 | *nfds_io=0; | |
179 | } | |
9d3a4132 SE |
180 | return 0; |
181 | } | |
182 | ||
90a39563 | 183 | static void userv_afterpoll(void *sst, struct pollfd *fds, int nfds) |
9d3a4132 SE |
184 | { |
185 | struct userv *st=sst; | |
186 | uint8_t rxbuf[DEFAULT_BUFSIZE]; | |
042a8da9 SE |
187 | int l; |
188 | ||
189 | if (nfds==0) return; | |
9d3a4132 SE |
190 | |
191 | if (fds[1].revents&POLLERR) { | |
469fd1d9 | 192 | Message(M_ERR,"%s: userv_afterpoll: POLLERR!\n",st->slip.nl.name); |
9d3a4132 SE |
193 | } |
194 | if (fds[1].revents&POLLIN) { | |
195 | l=read(st->rxfd,rxbuf,DEFAULT_BUFSIZE); | |
196 | if (l<0) { | |
042a8da9 SE |
197 | if (errno!=EINTR) |
198 | fatal_perror("%s: userv_afterpoll: read(rxfd)", | |
199 | st->slip.nl.name); | |
200 | } else if (l==0) { | |
4f5e39ec | 201 | fatal("%s: userv_afterpoll: read(rxfd)=0; userv gone away?", |
042a8da9 SE |
202 | st->slip.nl.name); |
203 | } else slip_unstuff(&st->slip,rxbuf,l); | |
9d3a4132 SE |
204 | } |
205 | } | |
206 | ||
207 | /* Send buf to the kernel. Free buf before returning. */ | |
469fd1d9 | 208 | static void userv_deliver_to_kernel(void *sst, struct buffer_if *buf) |
9d3a4132 SE |
209 | { |
210 | struct userv *st=sst; | |
9d3a4132 | 211 | |
042a8da9 SE |
212 | slip_stuff(&st->slip,buf,st->txfd); |
213 | } | |
9d3a4132 | 214 | |
042a8da9 SE |
215 | static void userv_userv_callback(void *sst, pid_t pid, int status) |
216 | { | |
217 | struct userv *st=sst; | |
218 | ||
219 | if (pid!=st->pid) { | |
220 | Message(M_WARNING,"userv_callback called unexpectedly with pid %d " | |
221 | "(expected %d)\n",pid,st->pid); | |
222 | return; | |
9d3a4132 | 223 | } |
042a8da9 SE |
224 | if (!st->expecting_userv_exit) { |
225 | if (WIFEXITED(status)) { | |
4f5e39ec | 226 | fatal("%s: userv exited unexpectedly with status %d", |
042a8da9 SE |
227 | st->slip.nl.name,WEXITSTATUS(status)); |
228 | } else if (WIFSIGNALED(status)) { | |
4f5e39ec | 229 | fatal("%s: userv exited unexpectedly: uncaught signal %d", |
042a8da9 SE |
230 | st->slip.nl.name,WTERMSIG(status)); |
231 | } else { | |
4f5e39ec | 232 | fatal("%s: userv stopped unexpectedly"); |
042a8da9 | 233 | } |
9d3a4132 | 234 | } |
042a8da9 SE |
235 | Message(M_WARNING,"%s: userv subprocess died with status %d\n", |
236 | st->slip.nl.name,WEXITSTATUS(status)); | |
237 | st->pid=0; | |
9d3a4132 SE |
238 | } |
239 | ||
042a8da9 | 240 | struct userv_entry_rec { |
fe5e9cc4 SE |
241 | cstring_t path; |
242 | const char **argv; | |
469fd1d9 SE |
243 | int in; |
244 | int out; | |
042a8da9 SE |
245 | /* XXX perhaps we should collect and log stderr? */ |
246 | }; | |
247 | ||
248 | static void userv_entry(void *sst) | |
9d3a4132 | 249 | { |
042a8da9 SE |
250 | struct userv_entry_rec *st=sst; |
251 | ||
469fd1d9 SE |
252 | dup2(st->in,0); |
253 | dup2(st->out,1); | |
042a8da9 SE |
254 | |
255 | /* XXX close all other fds */ | |
256 | setsid(); | |
fe5e9cc4 SE |
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); | |
042a8da9 SE |
260 | perror("userv-entry: execvp()"); |
261 | exit(1); | |
262 | } | |
263 | ||
264 | static void userv_invoke_userv(struct userv *st) | |
265 | { | |
266 | struct userv_entry_rec *er; | |
9d3a4132 SE |
267 | int c_stdin[2]; |
268 | int c_stdout[2]; | |
269 | string_t addrs; | |
270 | string_t nets; | |
271 | string_t s; | |
d3fe100d SE |
272 | struct netlink_client *r; |
273 | struct ipset *allnets; | |
794f2398 | 274 | struct subnet_list *snets; |
4f5e39ec | 275 | int i, nread; |
042a8da9 SE |
276 | uint8_t confirm; |
277 | ||
278 | if (st->pid) { | |
4f5e39ec | 279 | fatal("userv_invoke_userv: already running"); |
042a8da9 | 280 | } |
9d3a4132 SE |
281 | |
282 | /* This is where we actually invoke userv - all the networks we'll | |
283 | be using should already have been registered. */ | |
284 | ||
042a8da9 SE |
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); | |
9d3a4132 | 289 | |
d3fe100d SE |
290 | allnets=ipset_new(); |
291 | for (r=st->slip.nl.clients; r; r=r->next) { | |
f208b9a9 IJ |
292 | if (r->link_quality > LINK_QUALITY_UNUSED) { |
293 | struct ipset *nan; | |
294 | r->kup=True; | |
295 | nan=ipset_union(allnets,r->networks); | |
296 | ipset_free(allnets); | |
297 | allnets=nan; | |
298 | } | |
9d3a4132 | 299 | } |
d3fe100d SE |
300 | snets=ipset_to_subnet_list(allnets); |
301 | ipset_free(allnets); | |
794f2398 SE |
302 | nets=safe_malloc(20*snets->entries,"userv_invoke_userv:nets"); |
303 | *nets=0; | |
304 | for (i=0; i<snets->entries; i++) { | |
305 | s=subnet_to_string(snets->list[i]); | |
306 | strcat(nets,s); | |
307 | strcat(nets,","); | |
308 | free(s); | |
309 | } | |
9d3a4132 | 310 | nets[strlen(nets)-1]=0; |
794f2398 | 311 | subnet_list_free(snets); |
9d3a4132 | 312 | |
042a8da9 | 313 | Message(M_INFO,"%s: about to invoke: %s %s %s %s %s\n",st->slip.nl.name, |
9d3a4132 SE |
314 | st->userv_path,st->service_user,st->service_name,addrs,nets); |
315 | ||
042a8da9 | 316 | st->slip.pending_esc=False; |
9d3a4132 SE |
317 | |
318 | /* Invoke userv */ | |
319 | if (pipe(c_stdin)!=0) { | |
042a8da9 | 320 | fatal_perror("userv_invoke_userv: pipe(c_stdin)"); |
9d3a4132 SE |
321 | } |
322 | if (pipe(c_stdout)!=0) { | |
042a8da9 | 323 | fatal_perror("userv_invoke_userv: pipe(c_stdout)"); |
9d3a4132 SE |
324 | } |
325 | st->txfd=c_stdin[1]; | |
326 | st->rxfd=c_stdout[0]; | |
327 | ||
042a8da9 SE |
328 | er=safe_malloc(sizeof(*r),"userv_invoke_userv: er"); |
329 | ||
469fd1d9 SE |
330 | er->in=c_stdin[0]; |
331 | er->out=c_stdout[1]; | |
042a8da9 SE |
332 | /* The arguments are: |
333 | userv | |
334 | service-user | |
335 | service-name | |
336 | local-addr,secnet-addr,mtu,protocol | |
337 | route1,route2,... */ | |
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; | |
342 | er->argv[3]=addrs; | |
343 | er->argv[4]=nets; | |
344 | er->argv[5]=NULL; | |
345 | er->path=st->userv_path; | |
346 | ||
347 | st->pid=makesubproc(userv_entry, userv_userv_callback, | |
348 | er, st, st->slip.nl.name); | |
469fd1d9 SE |
349 | close(er->in); |
350 | close(er->out); | |
042a8da9 SE |
351 | free(er->argv); |
352 | free(er); | |
353 | free(addrs); | |
354 | free(nets); | |
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. */ | |
4f5e39ec | 358 | if ((nread=read(st->rxfd,&confirm,1))!=1) { |
042a8da9 SE |
359 | if (errno==EINTR) { |
360 | Message(M_WARNING,"%s: read of confirmation byte was " | |
361 | "interrupted\n",st->slip.nl.name); | |
362 | } else { | |
4f5e39ec SE |
363 | if (nread<0) { |
364 | fatal_perror("%s: error reading confirmation byte", | |
365 | st->slip.nl.name); | |
366 | } else { | |
367 | fatal("%s: unexpected EOF instead of confirmation byte" | |
368 | " - userv ipif failed?", st->slip.nl.name); | |
369 | } | |
042a8da9 SE |
370 | } |
371 | } else { | |
372 | if (confirm!=SLIP_END) { | |
4f5e39ec | 373 | fatal("%s: bad confirmation byte %d from userv-ipif", |
042a8da9 SE |
374 | st->slip.nl.name,confirm); |
375 | } | |
9d3a4132 | 376 | } |
042a8da9 SE |
377 | } |
378 | ||
379 | static void userv_kill_userv(struct userv *st) | |
380 | { | |
381 | if (st->pid) { | |
382 | kill(-st->pid,SIGTERM); | |
383 | st->expecting_userv_exit=True; | |
384 | } | |
385 | } | |
386 | ||
387 | static void userv_phase_hook(void *sst, uint32_t newphase) | |
388 | { | |
389 | struct userv *st=sst; | |
390 | /* We must wait until signal processing has started before forking | |
391 | userv */ | |
392 | if (newphase==PHASE_RUN) { | |
393 | userv_invoke_userv(st); | |
394 | /* Register for poll() */ | |
395 | register_for_poll(st, userv_beforepoll, userv_afterpoll, 2, | |
396 | st->slip.nl.name); | |
397 | } | |
398 | if (newphase==PHASE_SHUTDOWN) { | |
399 | userv_kill_userv(st); | |
9d3a4132 | 400 | } |
9d3a4132 SE |
401 | } |
402 | ||
403 | static list_t *userv_apply(closure_t *self, struct cloc loc, dict_t *context, | |
404 | list_t *args) | |
405 | { | |
406 | struct userv *st; | |
407 | item_t *item; | |
408 | dict_t *dict; | |
409 | ||
410 | st=safe_malloc(sizeof(*st),"userv_apply"); | |
411 | ||
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"); | |
416 | ||
417 | dict=item->data.dict; | |
418 | ||
042a8da9 SE |
419 | slip_init(&st->slip,loc,dict,"netlink-userv-ipif", |
420 | userv_deliver_to_kernel); | |
9d3a4132 SE |
421 | |
422 | st->userv_path=dict_read_string(dict,"userv-path",False,"userv-netlink", | |
423 | loc); | |
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"; | |
9d3a4132 | 431 | st->rxfd=-1; st->txfd=-1; |
042a8da9 SE |
432 | st->pid=0; |
433 | st->expecting_userv_exit=False; | |
434 | add_hook(PHASE_RUN,userv_phase_hook,st); | |
435 | add_hook(PHASE_SHUTDOWN,userv_phase_hook,st); | |
9d3a4132 | 436 | |
042a8da9 | 437 | return new_closure(&st->slip.nl.cl); |
9d3a4132 SE |
438 | } |
439 | ||
9d3a4132 SE |
440 | void slip_module(dict_t *dict) |
441 | { | |
442 | add_closure(dict,"userv-ipif",userv_apply); | |
9d3a4132 | 443 | } |