Import release 0.1.10
[secnet] / slip.c
CommitLineData
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
21struct 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
32static void slip_stuff(struct slip *st, struct buffer_if *buf, int fd)
33{
34 uint8_t txbuf[DEFAULT_BUFSIZE];
35 uint8_t *i;
36 uint32_t j=0;
37
38 BUF_ASSERT_USED(buf);
39
40 /* XXX crunchy bytestuff code */
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
70static void slip_unstuff(struct slip *st, uint8_t *buf, uint32_t l)
71{
72 uint32_t i;
73
74 /* XXX really crude unstuff code */
75 /* XXX check for buffer overflow */
76 BUF_ASSERT_USED(st->buff);
77 for (i=0; i<l; i++) {
78 if (st->pending_esc) {
79 st->pending_esc=False;
80 switch(buf[i]) {
81 case SLIP_ESCEND:
82 *(uint8_t *)buf_append(st->buff,1)=SLIP_END;
83 break;
84 case SLIP_ESCESC:
85 *(uint8_t *)buf_append(st->buff,1)=SLIP_ESC;
86 break;
87 default:
88 fatal("userv_afterpoll: bad SLIP escape character\n");
89 }
90 } else {
91 switch (buf[i]) {
92 case SLIP_END:
93 if (st->buff->size>0) {
469fd1d9 94 st->netlink_to_tunnel(&st->nl,st->buff);
042a8da9
SE
95 BUF_ALLOC(st->buff,"userv_afterpoll");
96 }
97 buffer_init(st->buff,st->nl.max_start_pad);
98 break;
99 case SLIP_ESC:
100 st->pending_esc=True;
101 break;
102 default:
103 *(uint8_t *)buf_append(st->buff,1)=buf[i];
104 break;
105 }
106 }
107 }
108}
109
110static void slip_init(struct slip *st, struct cloc loc, dict_t *dict,
111 string_t name, netlink_deliver_fn *to_host)
112{
113 st->netlink_to_tunnel=
114 netlink_init(&st->nl,st,loc,dict,
115 "netlink-userv-ipif",NULL,to_host);
116 st->buff=find_cl_if(dict,"buffer",CL_BUFFER,True,"name",loc);
117 st->local_address=string_to_ipaddr(
118 dict_find_item(dict,"local-address", True, name, loc),"netlink");
119 BUF_ALLOC(st->buff,"slip_init");
120 st->pending_esc=False;
121}
122
9d3a4132
SE
123/* Connection to the kernel through userv-ipif */
124
125struct userv {
042a8da9 126 struct slip slip;
9d3a4132
SE
127 int txfd; /* We transmit to userv */
128 int rxfd; /* We receive from userv */
129 string_t userv_path;
130 string_t service_user;
131 string_t service_name;
042a8da9
SE
132 pid_t pid;
133 bool_t expecting_userv_exit;
9d3a4132
SE
134};
135
136static int userv_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
137 int *timeout_io, const struct timeval *tv_now,
138 uint64_t *now)
139{
140 struct userv *st=sst;
042a8da9
SE
141
142 if (st->rxfd!=-1) {
143 *nfds_io=2;
144 fds[0].fd=st->txfd;
145 fds[0].events=POLLERR; /* Might want to pick up POLLOUT sometime */
146 fds[1].fd=st->rxfd;
147 fds[1].events=POLLIN|POLLERR|POLLHUP;
148 } else {
149 *nfds_io=0;
150 }
9d3a4132
SE
151 return 0;
152}
153
154static void userv_afterpoll(void *sst, struct pollfd *fds, int nfds,
155 const struct timeval *tv_now, uint64_t *now)
156{
157 struct userv *st=sst;
158 uint8_t rxbuf[DEFAULT_BUFSIZE];
042a8da9
SE
159 int l;
160
161 if (nfds==0) return;
9d3a4132
SE
162
163 if (fds[1].revents&POLLERR) {
469fd1d9 164 Message(M_ERR,"%s: userv_afterpoll: POLLERR!\n",st->slip.nl.name);
9d3a4132
SE
165 }
166 if (fds[1].revents&POLLIN) {
167 l=read(st->rxfd,rxbuf,DEFAULT_BUFSIZE);
168 if (l<0) {
042a8da9
SE
169 if (errno!=EINTR)
170 fatal_perror("%s: userv_afterpoll: read(rxfd)",
171 st->slip.nl.name);
172 } else if (l==0) {
9d3a4132 173 fatal("%s: userv_afterpoll: read(rxfd)=0; userv gone away?\n",
042a8da9
SE
174 st->slip.nl.name);
175 } else slip_unstuff(&st->slip,rxbuf,l);
9d3a4132
SE
176 }
177}
178
179/* Send buf to the kernel. Free buf before returning. */
469fd1d9 180static void userv_deliver_to_kernel(void *sst, struct buffer_if *buf)
9d3a4132
SE
181{
182 struct userv *st=sst;
9d3a4132 183
042a8da9
SE
184 slip_stuff(&st->slip,buf,st->txfd);
185}
9d3a4132 186
042a8da9
SE
187static void userv_userv_callback(void *sst, pid_t pid, int status)
188{
189 struct userv *st=sst;
190
191 if (pid!=st->pid) {
192 Message(M_WARNING,"userv_callback called unexpectedly with pid %d "
193 "(expected %d)\n",pid,st->pid);
194 return;
9d3a4132 195 }
042a8da9
SE
196 if (!st->expecting_userv_exit) {
197 if (WIFEXITED(status)) {
198 fatal("%s: userv exited unexpectedly with status %d\n",
199 st->slip.nl.name,WEXITSTATUS(status));
200 } else if (WIFSIGNALED(status)) {
201 fatal("%s: userv exited unexpectedly: uncaught signal %d\n",
202 st->slip.nl.name,WTERMSIG(status));
203 } else {
204 fatal("%s: userv stopped unexpectedly\n");
205 }
9d3a4132 206 }
042a8da9
SE
207 Message(M_WARNING,"%s: userv subprocess died with status %d\n",
208 st->slip.nl.name,WEXITSTATUS(status));
209 st->pid=0;
9d3a4132
SE
210}
211
042a8da9
SE
212struct userv_entry_rec {
213 string_t path;
214 char **argv;
469fd1d9
SE
215 int in;
216 int out;
042a8da9
SE
217 /* XXX perhaps we should collect and log stderr? */
218};
219
220static void userv_entry(void *sst)
9d3a4132 221{
042a8da9
SE
222 struct userv_entry_rec *st=sst;
223
469fd1d9
SE
224 dup2(st->in,0);
225 dup2(st->out,1);
042a8da9
SE
226
227 /* XXX close all other fds */
228 setsid();
229 execvp(st->path,st->argv);
230 perror("userv-entry: execvp()");
231 exit(1);
232}
233
234static 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;
242 struct netlink_route *r;
243 int i;
042a8da9
SE
244 uint8_t confirm;
245
246 if (st->pid) {
247 fatal("userv_invoke_userv: already running\n");
248 }
9d3a4132
SE
249
250 /* This is where we actually invoke userv - all the networks we'll
251 be using should already have been registered. */
252
042a8da9
SE
253 addrs=safe_malloc(512,"userv_invoke_userv:addrs");
254 snprintf(addrs,512,"%s,%s,%d,slip",
255 ipaddr_to_string(st->slip.local_address),
256 ipaddr_to_string(st->slip.nl.secnet_address),st->slip.nl.mtu);
9d3a4132 257
042a8da9 258 nets=safe_malloc(1024,"userv_invoke_userv:nets");
9d3a4132 259 *nets=0;
042a8da9
SE
260 r=st->slip.nl.routes;
261 for (i=0; i<st->slip.nl.n_routes; i++) {
9d3a4132
SE
262 if (r[i].up) {
263 r[i].kup=True;
264 s=subnet_to_string(&r[i].net);
265 strcat(nets,s);
266 strcat(nets,",");
267 free(s);
268 }
269 }
270 nets[strlen(nets)-1]=0;
271
042a8da9 272 Message(M_INFO,"%s: about to invoke: %s %s %s %s %s\n",st->slip.nl.name,
9d3a4132
SE
273 st->userv_path,st->service_user,st->service_name,addrs,nets);
274
042a8da9 275 st->slip.pending_esc=False;
9d3a4132
SE
276
277 /* Invoke userv */
278 if (pipe(c_stdin)!=0) {
042a8da9 279 fatal_perror("userv_invoke_userv: pipe(c_stdin)");
9d3a4132
SE
280 }
281 if (pipe(c_stdout)!=0) {
042a8da9 282 fatal_perror("userv_invoke_userv: pipe(c_stdout)");
9d3a4132
SE
283 }
284 st->txfd=c_stdin[1];
285 st->rxfd=c_stdout[0];
286
042a8da9
SE
287 er=safe_malloc(sizeof(*r),"userv_invoke_userv: er");
288
469fd1d9
SE
289 er->in=c_stdin[0];
290 er->out=c_stdout[1];
042a8da9
SE
291 /* The arguments are:
292 userv
293 service-user
294 service-name
295 local-addr,secnet-addr,mtu,protocol
296 route1,route2,... */
297 er->argv=safe_malloc(sizeof(*er->argv)*6,"userv_invoke_userv:argv");
298 er->argv[0]=st->userv_path;
299 er->argv[1]=st->service_user;
300 er->argv[2]=st->service_name;
301 er->argv[3]=addrs;
302 er->argv[4]=nets;
303 er->argv[5]=NULL;
304 er->path=st->userv_path;
305
306 st->pid=makesubproc(userv_entry, userv_userv_callback,
307 er, st, st->slip.nl.name);
469fd1d9
SE
308 close(er->in);
309 close(er->out);
042a8da9
SE
310 free(er->argv);
311 free(er);
312 free(addrs);
313 free(nets);
314 Message(M_INFO,"%s: userv-ipif pid is %d\n",st->slip.nl.name,st->pid);
315 /* Read a single character from the pipe to confirm userv-ipif is
316 running. If we get a SIGCHLD at this point then we'll get EINTR. */
317 if (read(st->rxfd,&confirm,1)!=1) {
318 if (errno==EINTR) {
319 Message(M_WARNING,"%s: read of confirmation byte was "
320 "interrupted\n",st->slip.nl.name);
321 } else {
322 fatal_perror("%s: read() of confirmation byte",st->slip.nl.name);
323 }
324 } else {
325 if (confirm!=SLIP_END) {
326 fatal("%s: bad confirmation byte %d from userv-ipif\n",
327 st->slip.nl.name,confirm);
328 }
9d3a4132 329 }
042a8da9
SE
330 /* Mark rxfd non-blocking */
331 if (fcntl(st->rxfd, F_SETFL, fcntl(st->rxfd, F_GETFL)|O_NONBLOCK)==-1) {
332 fatal_perror("%s: fcntl(O_NONBLOCK)",st->slip.nl.name);
333 }
334}
335
336static void userv_kill_userv(struct userv *st)
337{
338 if (st->pid) {
339 kill(-st->pid,SIGTERM);
340 st->expecting_userv_exit=True;
341 }
342}
343
344static void userv_phase_hook(void *sst, uint32_t newphase)
345{
346 struct userv *st=sst;
347 /* We must wait until signal processing has started before forking
348 userv */
349 if (newphase==PHASE_RUN) {
350 userv_invoke_userv(st);
351 /* Register for poll() */
352 register_for_poll(st, userv_beforepoll, userv_afterpoll, 2,
353 st->slip.nl.name);
354 }
355 if (newphase==PHASE_SHUTDOWN) {
356 userv_kill_userv(st);
9d3a4132 357 }
9d3a4132
SE
358}
359
360static list_t *userv_apply(closure_t *self, struct cloc loc, dict_t *context,
361 list_t *args)
362{
363 struct userv *st;
364 item_t *item;
365 dict_t *dict;
366
367 st=safe_malloc(sizeof(*st),"userv_apply");
368
369 /* First parameter must be a dict */
370 item=list_elem(args,0);
371 if (!item || item->type!=t_dict)
372 cfgfatal(loc,"userv-ipif","parameter must be a dictionary\n");
373
374 dict=item->data.dict;
375
042a8da9
SE
376 slip_init(&st->slip,loc,dict,"netlink-userv-ipif",
377 userv_deliver_to_kernel);
9d3a4132
SE
378
379 st->userv_path=dict_read_string(dict,"userv-path",False,"userv-netlink",
380 loc);
381 st->service_user=dict_read_string(dict,"service-user",False,
382 "userv-netlink",loc);
383 st->service_name=dict_read_string(dict,"service-name",False,
384 "userv-netlink",loc);
385 if (!st->userv_path) st->userv_path="userv";
386 if (!st->service_user) st->service_user="root";
387 if (!st->service_name) st->service_name="ipif";
9d3a4132 388 st->rxfd=-1; st->txfd=-1;
042a8da9
SE
389 st->pid=0;
390 st->expecting_userv_exit=False;
391 add_hook(PHASE_RUN,userv_phase_hook,st);
392 add_hook(PHASE_SHUTDOWN,userv_phase_hook,st);
9d3a4132 393
042a8da9 394 return new_closure(&st->slip.nl.cl);
9d3a4132
SE
395}
396
397init_module slip_module;
398void slip_module(dict_t *dict)
399{
400 add_closure(dict,"userv-ipif",userv_apply);
401#if 0
402 /* TODO */
403 add_closure(dict,"pty-slip",ptyslip_apply);
404 add_closure(dict,"slipd",slipd_apply);
405#endif /* 0 */
406}