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; | |
26 | netlink_deliver_fn *netlink_to_tunnel; | |
27 | uint32_t local_address; | |
28 | }; | |
29 | ||
30 | /* Generic SLIP mangling code */ | |
31 | ||
32 | static void slip_stuff(struct slip *st, struct buffer_if *buf, int fd) | |
33 | { | |
34 | uint8_t txbuf[DEFAULT_BUFSIZE]; | |
35 | uint8_t *i; | |
1caa23ff | 36 | int32_t j=0; |
042a8da9 SE |
37 | |
38 | BUF_ASSERT_USED(buf); | |
39 | ||
d3fe100d | 40 | /* There's probably a much more efficient way of implementing this */ |
042a8da9 SE |
41 | txbuf[j++]=SLIP_END; |
42 | for (i=buf->start; i<(buf->start+buf->size); i++) { | |
43 | switch (*i) { | |
44 | case SLIP_END: | |
45 | txbuf[j++]=SLIP_ESC; | |
46 | txbuf[j++]=SLIP_ESCEND; | |
47 | break; | |
48 | case SLIP_ESC: | |
49 | txbuf[j++]=SLIP_ESC; | |
50 | txbuf[j++]=SLIP_ESCESC; | |
51 | break; | |
52 | default: | |
53 | txbuf[j++]=*i; | |
54 | break; | |
55 | } | |
56 | if ((j+2)>DEFAULT_BUFSIZE) { | |
57 | if (write(fd,txbuf,j)<0) { | |
58 | fatal_perror("slip_stuff: write()"); | |
59 | } | |
60 | j=0; | |
61 | } | |
62 | } | |
63 | txbuf[j++]=SLIP_END; | |
64 | if (write(fd,txbuf,j)<0) { | |
65 | fatal_perror("slip_stuff: write()"); | |
66 | } | |
67 | BUF_FREE(buf); | |
68 | } | |
69 | ||
70 | static void slip_unstuff(struct slip *st, uint8_t *buf, uint32_t l) | |
71 | { | |
72 | uint32_t i; | |
73 | ||
042a8da9 SE |
74 | BUF_ASSERT_USED(st->buff); |
75 | for (i=0; i<l; i++) { | |
76 | if (st->pending_esc) { | |
77 | st->pending_esc=False; | |
78 | switch(buf[i]) { | |
79 | case SLIP_ESCEND: | |
80 | *(uint8_t *)buf_append(st->buff,1)=SLIP_END; | |
81 | break; | |
82 | case SLIP_ESCESC: | |
83 | *(uint8_t *)buf_append(st->buff,1)=SLIP_ESC; | |
84 | break; | |
85 | default: | |
4f5e39ec | 86 | fatal("userv_afterpoll: bad SLIP escape character"); |
042a8da9 SE |
87 | } |
88 | } else { | |
89 | switch (buf[i]) { | |
90 | case SLIP_END: | |
91 | if (st->buff->size>0) { | |
469fd1d9 | 92 | st->netlink_to_tunnel(&st->nl,st->buff); |
042a8da9 SE |
93 | BUF_ALLOC(st->buff,"userv_afterpoll"); |
94 | } | |
95 | buffer_init(st->buff,st->nl.max_start_pad); | |
96 | break; | |
97 | case SLIP_ESC: | |
98 | st->pending_esc=True; | |
99 | break; | |
100 | default: | |
101 | *(uint8_t *)buf_append(st->buff,1)=buf[i]; | |
102 | break; | |
103 | } | |
104 | } | |
105 | } | |
106 | } | |
107 | ||
108 | static void slip_init(struct slip *st, struct cloc loc, dict_t *dict, | |
fe5e9cc4 | 109 | cstring_t name, netlink_deliver_fn *to_host) |
042a8da9 SE |
110 | { |
111 | st->netlink_to_tunnel= | |
112 | netlink_init(&st->nl,st,loc,dict, | |
113 | "netlink-userv-ipif",NULL,to_host); | |
114 | st->buff=find_cl_if(dict,"buffer",CL_BUFFER,True,"name",loc); | |
794f2398 | 115 | st->local_address=string_item_to_ipaddr( |
042a8da9 SE |
116 | dict_find_item(dict,"local-address", True, name, loc),"netlink"); |
117 | BUF_ALLOC(st->buff,"slip_init"); | |
118 | st->pending_esc=False; | |
119 | } | |
120 | ||
9d3a4132 SE |
121 | /* Connection to the kernel through userv-ipif */ |
122 | ||
123 | struct userv { | |
042a8da9 | 124 | struct slip slip; |
9d3a4132 SE |
125 | int txfd; /* We transmit to userv */ |
126 | int rxfd; /* We receive from userv */ | |
fe5e9cc4 SE |
127 | cstring_t userv_path; |
128 | cstring_t service_user; | |
129 | cstring_t service_name; | |
042a8da9 SE |
130 | pid_t pid; |
131 | bool_t expecting_userv_exit; | |
9d3a4132 SE |
132 | }; |
133 | ||
134 | static int userv_beforepoll(void *sst, struct pollfd *fds, int *nfds_io, | |
135 | int *timeout_io, const struct timeval *tv_now, | |
136 | uint64_t *now) | |
137 | { | |
138 | struct userv *st=sst; | |
042a8da9 SE |
139 | |
140 | if (st->rxfd!=-1) { | |
141 | *nfds_io=2; | |
142 | fds[0].fd=st->txfd; | |
fe5e9cc4 | 143 | fds[0].events=0; /* Might want to pick up POLLOUT sometime */ |
042a8da9 | 144 | fds[1].fd=st->rxfd; |
fe5e9cc4 | 145 | fds[1].events=POLLIN; |
042a8da9 SE |
146 | } else { |
147 | *nfds_io=0; | |
148 | } | |
9d3a4132 SE |
149 | return 0; |
150 | } | |
151 | ||
152 | static void userv_afterpoll(void *sst, struct pollfd *fds, int nfds, | |
153 | const struct timeval *tv_now, uint64_t *now) | |
154 | { | |
155 | struct userv *st=sst; | |
156 | uint8_t rxbuf[DEFAULT_BUFSIZE]; | |
042a8da9 SE |
157 | int l; |
158 | ||
159 | if (nfds==0) return; | |
9d3a4132 SE |
160 | |
161 | if (fds[1].revents&POLLERR) { | |
469fd1d9 | 162 | Message(M_ERR,"%s: userv_afterpoll: POLLERR!\n",st->slip.nl.name); |
9d3a4132 SE |
163 | } |
164 | if (fds[1].revents&POLLIN) { | |
165 | l=read(st->rxfd,rxbuf,DEFAULT_BUFSIZE); | |
166 | if (l<0) { | |
042a8da9 SE |
167 | if (errno!=EINTR) |
168 | fatal_perror("%s: userv_afterpoll: read(rxfd)", | |
169 | st->slip.nl.name); | |
170 | } else if (l==0) { | |
4f5e39ec | 171 | fatal("%s: userv_afterpoll: read(rxfd)=0; userv gone away?", |
042a8da9 SE |
172 | st->slip.nl.name); |
173 | } else slip_unstuff(&st->slip,rxbuf,l); | |
9d3a4132 SE |
174 | } |
175 | } | |
176 | ||
177 | /* Send buf to the kernel. Free buf before returning. */ | |
469fd1d9 | 178 | static void userv_deliver_to_kernel(void *sst, struct buffer_if *buf) |
9d3a4132 SE |
179 | { |
180 | struct userv *st=sst; | |
9d3a4132 | 181 | |
042a8da9 SE |
182 | slip_stuff(&st->slip,buf,st->txfd); |
183 | } | |
9d3a4132 | 184 | |
042a8da9 SE |
185 | static void userv_userv_callback(void *sst, pid_t pid, int status) |
186 | { | |
187 | struct userv *st=sst; | |
188 | ||
189 | if (pid!=st->pid) { | |
190 | Message(M_WARNING,"userv_callback called unexpectedly with pid %d " | |
191 | "(expected %d)\n",pid,st->pid); | |
192 | return; | |
9d3a4132 | 193 | } |
042a8da9 SE |
194 | if (!st->expecting_userv_exit) { |
195 | if (WIFEXITED(status)) { | |
4f5e39ec | 196 | fatal("%s: userv exited unexpectedly with status %d", |
042a8da9 SE |
197 | st->slip.nl.name,WEXITSTATUS(status)); |
198 | } else if (WIFSIGNALED(status)) { | |
4f5e39ec | 199 | fatal("%s: userv exited unexpectedly: uncaught signal %d", |
042a8da9 SE |
200 | st->slip.nl.name,WTERMSIG(status)); |
201 | } else { | |
4f5e39ec | 202 | fatal("%s: userv stopped unexpectedly"); |
042a8da9 | 203 | } |
9d3a4132 | 204 | } |
042a8da9 SE |
205 | Message(M_WARNING,"%s: userv subprocess died with status %d\n", |
206 | st->slip.nl.name,WEXITSTATUS(status)); | |
207 | st->pid=0; | |
9d3a4132 SE |
208 | } |
209 | ||
042a8da9 | 210 | struct userv_entry_rec { |
fe5e9cc4 SE |
211 | cstring_t path; |
212 | const char **argv; | |
469fd1d9 SE |
213 | int in; |
214 | int out; | |
042a8da9 SE |
215 | /* XXX perhaps we should collect and log stderr? */ |
216 | }; | |
217 | ||
218 | static void userv_entry(void *sst) | |
9d3a4132 | 219 | { |
042a8da9 SE |
220 | struct userv_entry_rec *st=sst; |
221 | ||
469fd1d9 SE |
222 | dup2(st->in,0); |
223 | dup2(st->out,1); | |
042a8da9 SE |
224 | |
225 | /* XXX close all other fds */ | |
226 | setsid(); | |
fe5e9cc4 SE |
227 | /* XXX We really should strdup() all of argv[] but because we'll just |
228 | exit anyway if execvp() fails it doesn't seem worth bothering. */ | |
229 | execvp(st->path,(char *const*)st->argv); | |
042a8da9 SE |
230 | perror("userv-entry: execvp()"); |
231 | exit(1); | |
232 | } | |
233 | ||
234 | static void userv_invoke_userv(struct userv *st) | |
235 | { | |
236 | struct userv_entry_rec *er; | |
9d3a4132 SE |
237 | int c_stdin[2]; |
238 | int c_stdout[2]; | |
239 | string_t addrs; | |
240 | string_t nets; | |
241 | string_t s; | |
d3fe100d SE |
242 | struct netlink_client *r; |
243 | struct ipset *allnets; | |
794f2398 | 244 | struct subnet_list *snets; |
4f5e39ec | 245 | int i, nread; |
042a8da9 SE |
246 | uint8_t confirm; |
247 | ||
248 | if (st->pid) { | |
4f5e39ec | 249 | fatal("userv_invoke_userv: already running"); |
042a8da9 | 250 | } |
9d3a4132 SE |
251 | |
252 | /* This is where we actually invoke userv - all the networks we'll | |
253 | be using should already have been registered. */ | |
254 | ||
042a8da9 SE |
255 | addrs=safe_malloc(512,"userv_invoke_userv:addrs"); |
256 | snprintf(addrs,512,"%s,%s,%d,slip", | |
257 | ipaddr_to_string(st->slip.local_address), | |
258 | ipaddr_to_string(st->slip.nl.secnet_address),st->slip.nl.mtu); | |
9d3a4132 | 259 | |
d3fe100d SE |
260 | allnets=ipset_new(); |
261 | for (r=st->slip.nl.clients; r; r=r->next) { | |
262 | if (r->up) { | |
263 | struct ipset *nan; | |
264 | r->kup=True; | |
265 | nan=ipset_union(allnets,r->networks); | |
266 | ipset_free(allnets); | |
267 | allnets=nan; | |
9d3a4132 SE |
268 | } |
269 | } | |
d3fe100d SE |
270 | snets=ipset_to_subnet_list(allnets); |
271 | ipset_free(allnets); | |
794f2398 SE |
272 | nets=safe_malloc(20*snets->entries,"userv_invoke_userv:nets"); |
273 | *nets=0; | |
274 | for (i=0; i<snets->entries; i++) { | |
275 | s=subnet_to_string(snets->list[i]); | |
276 | strcat(nets,s); | |
277 | strcat(nets,","); | |
278 | free(s); | |
279 | } | |
9d3a4132 | 280 | nets[strlen(nets)-1]=0; |
794f2398 | 281 | subnet_list_free(snets); |
9d3a4132 | 282 | |
042a8da9 | 283 | Message(M_INFO,"%s: about to invoke: %s %s %s %s %s\n",st->slip.nl.name, |
9d3a4132 SE |
284 | st->userv_path,st->service_user,st->service_name,addrs,nets); |
285 | ||
042a8da9 | 286 | st->slip.pending_esc=False; |
9d3a4132 SE |
287 | |
288 | /* Invoke userv */ | |
289 | if (pipe(c_stdin)!=0) { | |
042a8da9 | 290 | fatal_perror("userv_invoke_userv: pipe(c_stdin)"); |
9d3a4132 SE |
291 | } |
292 | if (pipe(c_stdout)!=0) { | |
042a8da9 | 293 | fatal_perror("userv_invoke_userv: pipe(c_stdout)"); |
9d3a4132 SE |
294 | } |
295 | st->txfd=c_stdin[1]; | |
296 | st->rxfd=c_stdout[0]; | |
297 | ||
042a8da9 SE |
298 | er=safe_malloc(sizeof(*r),"userv_invoke_userv: er"); |
299 | ||
469fd1d9 SE |
300 | er->in=c_stdin[0]; |
301 | er->out=c_stdout[1]; | |
042a8da9 SE |
302 | /* The arguments are: |
303 | userv | |
304 | service-user | |
305 | service-name | |
306 | local-addr,secnet-addr,mtu,protocol | |
307 | route1,route2,... */ | |
308 | er->argv=safe_malloc(sizeof(*er->argv)*6,"userv_invoke_userv:argv"); | |
309 | er->argv[0]=st->userv_path; | |
310 | er->argv[1]=st->service_user; | |
311 | er->argv[2]=st->service_name; | |
312 | er->argv[3]=addrs; | |
313 | er->argv[4]=nets; | |
314 | er->argv[5]=NULL; | |
315 | er->path=st->userv_path; | |
316 | ||
317 | st->pid=makesubproc(userv_entry, userv_userv_callback, | |
318 | er, st, st->slip.nl.name); | |
469fd1d9 SE |
319 | close(er->in); |
320 | close(er->out); | |
042a8da9 SE |
321 | free(er->argv); |
322 | free(er); | |
323 | free(addrs); | |
324 | free(nets); | |
325 | Message(M_INFO,"%s: userv-ipif pid is %d\n",st->slip.nl.name,st->pid); | |
326 | /* Read a single character from the pipe to confirm userv-ipif is | |
327 | running. If we get a SIGCHLD at this point then we'll get EINTR. */ | |
4f5e39ec | 328 | if ((nread=read(st->rxfd,&confirm,1))!=1) { |
042a8da9 SE |
329 | if (errno==EINTR) { |
330 | Message(M_WARNING,"%s: read of confirmation byte was " | |
331 | "interrupted\n",st->slip.nl.name); | |
332 | } else { | |
4f5e39ec SE |
333 | if (nread<0) { |
334 | fatal_perror("%s: error reading confirmation byte", | |
335 | st->slip.nl.name); | |
336 | } else { | |
337 | fatal("%s: unexpected EOF instead of confirmation byte" | |
338 | " - userv ipif failed?", st->slip.nl.name); | |
339 | } | |
042a8da9 SE |
340 | } |
341 | } else { | |
342 | if (confirm!=SLIP_END) { | |
4f5e39ec | 343 | fatal("%s: bad confirmation byte %d from userv-ipif", |
042a8da9 SE |
344 | st->slip.nl.name,confirm); |
345 | } | |
9d3a4132 | 346 | } |
042a8da9 SE |
347 | } |
348 | ||
349 | static void userv_kill_userv(struct userv *st) | |
350 | { | |
351 | if (st->pid) { | |
352 | kill(-st->pid,SIGTERM); | |
353 | st->expecting_userv_exit=True; | |
354 | } | |
355 | } | |
356 | ||
357 | static void userv_phase_hook(void *sst, uint32_t newphase) | |
358 | { | |
359 | struct userv *st=sst; | |
360 | /* We must wait until signal processing has started before forking | |
361 | userv */ | |
362 | if (newphase==PHASE_RUN) { | |
363 | userv_invoke_userv(st); | |
364 | /* Register for poll() */ | |
365 | register_for_poll(st, userv_beforepoll, userv_afterpoll, 2, | |
366 | st->slip.nl.name); | |
367 | } | |
368 | if (newphase==PHASE_SHUTDOWN) { | |
369 | userv_kill_userv(st); | |
9d3a4132 | 370 | } |
9d3a4132 SE |
371 | } |
372 | ||
373 | static list_t *userv_apply(closure_t *self, struct cloc loc, dict_t *context, | |
374 | list_t *args) | |
375 | { | |
376 | struct userv *st; | |
377 | item_t *item; | |
378 | dict_t *dict; | |
379 | ||
380 | st=safe_malloc(sizeof(*st),"userv_apply"); | |
381 | ||
382 | /* First parameter must be a dict */ | |
383 | item=list_elem(args,0); | |
384 | if (!item || item->type!=t_dict) | |
385 | cfgfatal(loc,"userv-ipif","parameter must be a dictionary\n"); | |
386 | ||
387 | dict=item->data.dict; | |
388 | ||
042a8da9 SE |
389 | slip_init(&st->slip,loc,dict,"netlink-userv-ipif", |
390 | userv_deliver_to_kernel); | |
9d3a4132 SE |
391 | |
392 | st->userv_path=dict_read_string(dict,"userv-path",False,"userv-netlink", | |
393 | loc); | |
394 | st->service_user=dict_read_string(dict,"service-user",False, | |
395 | "userv-netlink",loc); | |
396 | st->service_name=dict_read_string(dict,"service-name",False, | |
397 | "userv-netlink",loc); | |
398 | if (!st->userv_path) st->userv_path="userv"; | |
399 | if (!st->service_user) st->service_user="root"; | |
400 | if (!st->service_name) st->service_name="ipif"; | |
9d3a4132 | 401 | st->rxfd=-1; st->txfd=-1; |
042a8da9 SE |
402 | st->pid=0; |
403 | st->expecting_userv_exit=False; | |
404 | add_hook(PHASE_RUN,userv_phase_hook,st); | |
405 | add_hook(PHASE_SHUTDOWN,userv_phase_hook,st); | |
9d3a4132 | 406 | |
042a8da9 | 407 | return new_closure(&st->slip.nl.cl); |
9d3a4132 SE |
408 | } |
409 | ||
9d3a4132 SE |
410 | void slip_module(dict_t *dict) |
411 | { | |
412 | add_closure(dict,"userv-ipif",userv_apply); | |
9d3a4132 | 413 | } |