1c1a9fa1 |
1 | /* |
2 | * userv service (or standalone program) |
3 | * for per-user IP subranges. |
4 | * |
5 | * This is invoked as root, directly from userv. |
6 | * Its arguments are supposed to be, in order: |
1e963473 |
7 | * <config> |
8 | * Specifies address ranges and gids which own them. |
1c1a9fa1 |
9 | * -- Indicates that the remaining arguments are user-supplied |
10 | * and therefore untrusted. |
11 | * <local-addr>,<peer-addr>,<mtu>,<proto> |
12 | * As for slattach. Supported protocols are slip, cslip, and |
13 | * adaptive. Alternatively, set to `debug' to print debugging |
0f91e874 |
14 | * info. <local-addr> is address of the interface on the local |
15 | * system; <peer-addr> is the address of the point-to-point peer. |
1c1a9fa1 |
16 | * <prefix>/<mask>,<prefix>/<mask>,... |
17 | * List of additional routes to add for this interface. |
2ed30784 |
18 | * May be the empty argument, or `-' if this is problematic. |
1c1a9fa1 |
19 | * |
1e963473 |
20 | * <config> is either |
0f91e874 |
21 | * <gid>,[=]<prefix>/<len>[,<junk>] |
1e963473 |
22 | * indicating that that gid may allocate addresses in |
23 | * the relevant subspace (<junk> is ignored) |
0f91e874 |
24 | * if `=' is specified then it's only allowed for the local |
25 | * endpoint address |
1e963473 |
26 | * or #... |
27 | * which is a comment |
28 | * or /<config-file-name> or ./<config-file-name> or ../<config-file-name> |
29 | * which refers to a file which contains lines which |
30 | * are each <config> |
31 | * or * |
32 | * which means that anything is permitted |
33 | * |
1c1a9fa1 |
34 | * Should be run from userv with no-disconnect-hup. |
35 | */ |
caa68336 |
36 | /* |
5edd1887 |
37 | * Copyright (C) 1999-2000 Ian Jackson |
caa68336 |
38 | * |
39 | * This is free software; you can redistribute it and/or modify it |
40 | * under the terms of the GNU General Public License as published by |
41 | * the Free Software Foundation; either version 2 of the License, or |
42 | * (at your option) any later version. |
43 | * |
44 | * This program is distributed in the hope that it will be useful, but |
45 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
46 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
47 | * General Public License for more details. |
48 | * |
49 | * You should have received a copy of the GNU General Public License |
50 | * along with userv-utils; if not, write to the Free Software |
51 | * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
52 | * |
53 | * $Id$ |
54 | */ |
1c1a9fa1 |
55 | |
56 | #include <stdio.h> |
57 | #include <string.h> |
58 | #include <stdlib.h> |
59 | #include <assert.h> |
60 | #include <errno.h> |
1e963473 |
61 | #include <stdarg.h> |
62 | #include <ctype.h> |
63 | #include <limits.h> |
02b2392d |
64 | #include <signal.h> |
65 | #include <unistd.h> |
66 | |
67 | #include <sys/types.h> |
68 | #include <sys/wait.h> |
69 | #include <sys/stat.h> |
1c1a9fa1 |
70 | |
1e963473 |
71 | #define NARGS 4 |
1c1a9fa1 |
72 | #define MAXEXROUTES 5 |
a48a8f0d |
73 | #define ATXTLEN 16 |
1c1a9fa1 |
74 | |
1e963473 |
75 | static const unsigned long gidmaxval= (unsigned long)((gid_t)-2); |
76 | static const char *const protos_ok[]= { "slip", "cslip", "adaptive", 0 }; |
02b2392d |
77 | static const int signals[]= { SIGHUP, SIGINT, SIGTERM, 0 }; |
1e963473 |
78 | |
79 | static const char *configstr, *proto; |
1c1a9fa1 |
80 | static unsigned long localaddr, peeraddr, mtu; |
1e963473 |
81 | static int localallow, peerallow, allallow; |
1c1a9fa1 |
82 | static int nexroutes; |
83 | static struct exroute { |
84 | unsigned long prefix, mask; |
1e963473 |
85 | int allow; |
1c1a9fa1 |
86 | char prefixtxt[ATXTLEN], masktxt[ATXTLEN]; |
87 | } exroutes[MAXEXROUTES]; |
88 | |
1e963473 |
89 | static char localtxt[ATXTLEN]; |
90 | static char peertxt[ATXTLEN]; |
91 | |
92 | static struct pplace { |
93 | struct pplace *parent; |
94 | const char *filename; |
95 | int lineno; |
96 | } *cpplace; |
97 | |
02b2392d |
98 | |
6d360a53 |
99 | static int slpipe[2], ptmaster, undoslattach; |
02b2392d |
100 | static const char *ifname; |
101 | static const char *ptyname; |
102 | |
103 | #define NPIDS 4 |
104 | |
105 | static union { |
106 | struct { pid_t sl, cout, cin, task; } byname; |
107 | pid_t bynumber[NPIDS]; |
108 | } pids; |
109 | sigset_t emptyset, fullset; |
110 | |
111 | |
6d360a53 |
112 | static int cleantask(void) { |
113 | pid_t pid; |
114 | |
115 | pid= fork(); |
116 | if (!pid) return 1; |
117 | if (pid == (pid_t)-1) |
118 | perror("userv-ipif: fork for undo slattach failed - cannot clean up properly"); |
119 | return 0; |
120 | } |
121 | |
02b2392d |
122 | static void terminate(int estatus) { |
123 | int i, status; |
124 | pid_t pid; |
125 | |
126 | for (i=0; i<NPIDS; i++) |
127 | if (pids.bynumber[i]) kill(pids.bynumber[i], SIGTERM); |
6d360a53 |
128 | |
129 | if (undoslattach) { |
130 | if (cleantask()) { |
131 | execlp("slattach", "slattach", "-p", "tty", ptyname, (char*)0); |
132 | perror("userv-ipif: exec slattach for undo slattach failed"); |
133 | exit(-1); |
134 | } |
135 | if (ifname && cleantask()) { |
136 | execlp("ifconfig", "ifconfig", ifname, "down", (char*)0); |
137 | perror("userv-ipif: exec ifconfig for undo ifconfig failed"); |
138 | exit(-1); |
139 | } |
140 | } |
141 | |
02b2392d |
142 | for (;;) { |
143 | pid= waitpid(-1,&status,0); |
144 | if (pid == (pid_t)-1) break; |
145 | } |
146 | exit(estatus); |
147 | } |
148 | |
149 | |
1e963473 |
150 | static void fatal(const char *fmt, ...) |
151 | __attribute__((format(printf,1,2))); |
152 | static void fatal(const char *fmt, ...) { |
153 | va_list al; |
154 | va_start(al,fmt); |
1c1a9fa1 |
155 | |
1e963473 |
156 | fputs("userv-ipif service: fatal error: ",stderr); |
157 | vfprintf(stderr, fmt, al); |
158 | putc('\n',stderr); |
02b2392d |
159 | terminate(8); |
1c1a9fa1 |
160 | } |
161 | |
1e963473 |
162 | static void sysfatal(const char *fmt, ...) |
163 | __attribute__((format(printf,1,2))); |
164 | static void sysfatal(const char *fmt, ...) { |
165 | va_list al; |
166 | int e; |
167 | |
168 | e= errno; |
169 | va_start(al,fmt); |
170 | |
6d360a53 |
171 | fputs("userv-ipif service: fatal system error: ",stderr); |
1e963473 |
172 | vfprintf(stderr, fmt, al); |
6d360a53 |
173 | fprintf(stderr,": %s\n", strerror(e)); |
02b2392d |
174 | terminate(12); |
1c1a9fa1 |
175 | } |
1e963473 |
176 | |
177 | |
178 | static void badusage(const char *fmt, ...) |
179 | __attribute__((format(printf,1,2))); |
180 | static void badusage(const char *fmt, ...) { |
181 | va_list al; |
182 | struct pplace *cpp; |
1c1a9fa1 |
183 | |
1e963473 |
184 | if (cpplace) { |
185 | fprintf(stderr, |
186 | "userv-ipif service: %s:%d: ", |
187 | cpplace->filename, cpplace->lineno); |
188 | } else { |
189 | fputs("userv-ipif service: invalid usage: ",stderr); |
190 | } |
191 | va_start(al,fmt); |
192 | vfprintf(stderr, fmt, al); |
193 | putc('\n',stderr); |
194 | |
195 | if (cpplace) { |
196 | for (cpp=cpplace->parent; cpp; cpp=cpp->parent) { |
197 | fprintf(stderr, |
198 | "userv-ipif service: %s:%d: ... in file included from here\n", |
199 | cpp->filename, cpp->lineno); |
200 | } |
201 | } |
02b2392d |
202 | terminate(16); |
1c1a9fa1 |
203 | } |
204 | |
205 | static char *ip2txt(unsigned long addr, char *buf) { |
206 | sprintf(buf, "%lu.%lu.%lu.%lu", |
207 | (addr>>24) & 0x0ff, |
208 | (addr>>16) & 0x0ff, |
209 | (addr>>8) & 0x0ff, |
210 | (addr) & 0x0ff); |
211 | return buf; |
212 | } |
213 | |
214 | static unsigned long eat_number(const char **argp, const char *what, |
215 | unsigned long min, unsigned long max, |
216 | const char *endchars, int *endchar_r) { |
217 | /* If !endchars then the endchar must be a nul, otherwise it may be |
218 | * a nul (resulting in *argp set to 0) or something else (*argp set |
219 | * to point to after delim, *endchar_r set to delim). |
220 | * *endchar_r may be 0. |
221 | */ |
222 | unsigned long rv; |
223 | char *ep; |
224 | int endchar; |
225 | |
baba1099 |
226 | if (!*argp) { badusage("missing number %s",what); } |
1c1a9fa1 |
227 | rv= strtoul(*argp,&ep,0); |
228 | if ((endchar= *ep)) { |
baba1099 |
229 | if (!endchars) badusage("junk after number %s",what); |
1e963473 |
230 | if (!strchr(endchars,endchar)) |
231 | badusage("invalid character or delimiter `%c' in or after number, %s:" |
baba1099 |
232 | " expected %s (or none?)", endchar,what,endchars); |
1c1a9fa1 |
233 | *argp= ep+1; |
234 | } else { |
235 | *argp= 0; |
236 | } |
237 | if (endchar_r) *endchar_r= endchar; |
1e963473 |
238 | if (rv < min || rv > max) badusage("number %s value %lu out of range %lu..%lu", |
239 | what, rv, min, max); |
1c1a9fa1 |
240 | return rv; |
241 | } |
242 | |
1c1a9fa1 |
243 | static void addrnet_mustdiffer(const char *w1, unsigned long p1, unsigned long m1, |
244 | const char *w2, unsigned long p2, unsigned long m2) { |
245 | unsigned long mask; |
246 | |
247 | mask= m1&m2; |
248 | if ((p1 & mask) != (p2 & mask)) return; |
1e963473 |
249 | badusage("%s %08lx/%08lx overlaps/clashes with %s %08lx/%08lx", |
250 | w1,p1,m1, w2,p2,m2); |
1c1a9fa1 |
251 | } |
252 | |
253 | static unsigned long eat_addr(const char **argp, const char *what, |
1c1a9fa1 |
254 | const char *endchars, int *endchar_r) { |
255 | char whatbuf[100]; |
256 | unsigned long rv; |
257 | int i; |
258 | |
1c1a9fa1 |
259 | for (rv=0, i=0; |
260 | i<4; |
261 | i++) { |
262 | rv <<= 8; |
263 | sprintf(whatbuf,"%s byte #%d",what,i); |
264 | rv |= eat_number(argp,whatbuf, 0,255, i<3 ? "." : endchars, endchar_r); |
265 | } |
266 | |
1c1a9fa1 |
267 | return rv; |
268 | } |
269 | |
270 | static void eat_prefixmask(const char **argp, const char *what, |
1c1a9fa1 |
271 | const char *endchars, int *endchar_r, |
272 | unsigned long *prefix_r, unsigned long *mask_r, int *len_r) { |
273 | /* mask_r and len_r may be 0 */ |
274 | char whatbuf[100]; |
275 | int len; |
276 | unsigned long prefix, mask; |
277 | |
1e963473 |
278 | prefix= eat_addr(argp,what, "/",0); |
1c1a9fa1 |
279 | sprintf(whatbuf,"%s length",what); |
280 | len= eat_number(argp,whatbuf, 0,32, endchars,endchar_r); |
281 | |
282 | mask= (~0UL << (32-len)); |
baba1099 |
283 | if (prefix & ~mask) badusage("%s prefix %08lx not fully contained in mask %08lx", |
1e963473 |
284 | what,prefix,mask); |
1c1a9fa1 |
285 | *prefix_r= prefix; |
286 | if (mask_r) *mask_r= mask; |
287 | if (len_r) *len_r= len; |
288 | } |
1e963473 |
289 | |
290 | static int addrnet_isin(unsigned long prefix, unsigned long mask, |
291 | unsigned long mprefix, unsigned long mmask) { |
292 | return !(~mask & mmask) && (prefix & mmask) == mprefix; |
293 | } |
1c1a9fa1 |
294 | |
1c1a9fa1 |
295 | |
0f91e874 |
296 | static void permit(unsigned long pprefix, unsigned long pmask, int localonly) { |
1e963473 |
297 | int i, any; |
1c1a9fa1 |
298 | |
1e963473 |
299 | assert(!(pprefix & ~pmask)); |
2c310400 |
300 | any= 0; |
1c1a9fa1 |
301 | |
0f91e874 |
302 | if (!proto) fputs(localonly ? "permits-l" : "permits",stdout); |
1e963473 |
303 | if (addrnet_isin(localaddr,~0UL, pprefix,pmask)) { |
304 | if (!proto) fputs(" local-addr",stdout); |
305 | any= localallow= 1; |
306 | } |
0f91e874 |
307 | if (!localonly) { |
308 | if (addrnet_isin(peeraddr,~0UL, pprefix,pmask)) { |
309 | if (!proto) fputs(" peer-addr",stdout); |
310 | any= peerallow= 1; |
311 | } |
312 | for (i=0; i<nexroutes; i++) { |
313 | if (addrnet_isin(exroutes[i].prefix,exroutes[i].mask, pprefix,pmask)) { |
314 | if (!proto) printf(" route#%d",i); |
315 | any= exroutes[i].allow= 1; |
316 | } |
1e963473 |
317 | } |
318 | } |
319 | if (!proto) { |
a48a8f0d |
320 | if (!any) fputs(" nothing",stdout); |
1e963473 |
321 | putchar('\n'); |
322 | } |
323 | } |
1c1a9fa1 |
324 | |
1e963473 |
325 | static void pconfig(const char *configstr, int truncated); |
326 | |
327 | static void pfile(const char *filename) { |
328 | FILE *file; |
329 | char buf[PATH_MAX]; |
330 | int l, truncated, c; |
331 | struct pplace npp, *cpp; |
332 | |
333 | for (cpp=cpplace; cpp; cpp=cpp->parent) { |
334 | if (!strcmp(cpp->filename,filename)) |
335 | badusage("recursive configuration file `%s'",filename); |
336 | } |
337 | |
338 | file= fopen(filename,"r"); |
339 | if (!file) |
340 | badusage("cannot open configuration file `%s': %s", filename, strerror(errno)); |
341 | |
342 | if (!proto) printf("config file `%s':\n",filename); |
343 | |
344 | npp.parent= cpplace; |
345 | npp.filename= filename; |
346 | npp.lineno= 0; |
347 | cpplace= &npp; |
348 | |
349 | while (fgets(buf, sizeof(buf), file)) { |
350 | npp.lineno++; |
351 | l= strlen(buf); |
352 | if (!l) continue; |
353 | |
354 | truncated= (buf[l-1] != '\n'); |
355 | while (l>0 && isspace((unsigned char) buf[l-1])) l--; |
356 | if (!l) continue; |
357 | buf[l]= 0; |
358 | |
359 | if (truncated) { |
360 | while ((c= getc(file)) != EOF && c != '\n'); |
361 | if (c == EOF) break; |
362 | } |
363 | |
364 | pconfig(buf,truncated); |
365 | } |
366 | if (ferror(file)) |
367 | badusage("failed while reading configuration file: %s", strerror(errno)); |
368 | |
369 | cpplace= npp.parent; |
370 | } |
371 | |
372 | static void pconfig(const char *configstr, int truncated) { |
373 | unsigned long fgid, tgid, pprefix, pmask; |
0f91e874 |
374 | int plen, localonly; |
1e963473 |
375 | char ptxt[ATXTLEN]; |
376 | const char *gidlist; |
377 | |
378 | switch (configstr[0]) { |
379 | case '*': |
380 | if (strcmp(configstr,"*")) badusage("`*' directive must be only thing on line"); |
0f91e874 |
381 | permit(0UL,0UL,0); |
1e963473 |
382 | return; |
383 | |
384 | case '#': |
385 | return; |
386 | |
387 | case '/': case '.': |
388 | if (truncated) badusage("filename too long (`%.100s...')",configstr); |
389 | pfile(configstr); |
390 | return; |
391 | |
392 | default: |
393 | if (!isdigit((unsigned char)configstr[0])) |
394 | badusage("unknown configuration directive"); |
395 | |
396 | fgid= eat_number(&configstr,"gid", 0,gidmaxval, ",",0); |
0f91e874 |
397 | if (configstr[0] == '=') { |
398 | localonly= 1; |
399 | configstr++; |
400 | } else { |
401 | localonly= 0; |
402 | } |
1e963473 |
403 | eat_prefixmask(&configstr,"permitted-prefix", ",",0, &pprefix,&pmask,&plen); |
404 | if (!configstr && truncated) badusage("gid,prefix/len,... spec too long"); |
405 | |
406 | if (!proto) printf(" %5lu,%s/%d: ", fgid, ip2txt(pprefix,ptxt), plen); |
407 | |
408 | gidlist= getenv("USERV_GID"); |
409 | if (!gidlist) fatal("USERV_GID not set"); |
1c1a9fa1 |
410 | for (;;) { |
1e963473 |
411 | if (!gidlist) { |
412 | if (!proto) printf("no matching gid\n"); |
413 | return; |
1c1a9fa1 |
414 | } |
1e963473 |
415 | tgid= eat_number(&gidlist,"userv-gid", 0,gidmaxval, " ",0); |
416 | if (tgid == fgid) break; |
1c1a9fa1 |
417 | } |
0f91e874 |
418 | permit(pprefix,pmask,localonly); |
1e963473 |
419 | return; |
1c1a9fa1 |
420 | } |
1e963473 |
421 | } |
422 | |
423 | static void checkallow(int allow, const char *what, |
424 | const char *prefixtxt, const char *masktxt) { |
425 | if (allow) return; |
426 | fprintf(stderr,"userv-ipif service: access denied for %s, %s/%s\n", |
427 | what, prefixtxt, masktxt); |
428 | allallow= 0; |
429 | } |
430 | |
431 | static void parseargs(int argc, const char *const *argv) { |
432 | unsigned long routeaddr, routemask; |
433 | const char *carg; |
434 | const char *const *cprotop; |
435 | int i; |
436 | char erwhatbuf[100], erwhatbuf2[100]; |
437 | |
438 | if (argc < NARGS+1) { badusage("too few arguments"); } |
439 | if (argc > NARGS+1) { badusage("too many arguments"); } |
440 | |
441 | configstr= *++argv; |
1c1a9fa1 |
442 | |
443 | carg= *++argv; |
1e963473 |
444 | if (strcmp(carg,"--")) badusage("separator argument `--' not found, got `%s'",carg); |
1c1a9fa1 |
445 | |
1e963473 |
446 | carg= *++argv; |
447 | localaddr= eat_addr(&carg,"local-addr", ",",0); |
448 | peeraddr= eat_addr(&carg,"peer-addr", ",",0); |
1c1a9fa1 |
449 | mtu= eat_number(&carg,"mtu", 576,65536, ",",0); |
1e963473 |
450 | localallow= peerallow= 0; |
1c1a9fa1 |
451 | |
452 | if (!strcmp(carg,"debug")) { |
453 | proto= 0; |
454 | } else { |
455 | for (cprotop= protos_ok; |
456 | (proto= *cprotop) && strcmp(proto,carg); |
457 | cprotop++); |
458 | if (!proto) fatal("invalid protocol"); |
459 | } |
460 | |
461 | addrnet_mustdiffer("local-addr",localaddr,~0UL, "peer-addr",peeraddr,~0UL); |
462 | |
463 | carg= *++argv; |
2ed30784 |
464 | if (strcmp(carg,"-")) { |
465 | for (nexroutes=0; |
466 | carg && *carg; |
467 | nexroutes++) { |
468 | if (nexroutes == MAXEXROUTES) |
469 | fatal("too many extra routes (only %d allowed)",MAXEXROUTES); |
470 | sprintf(erwhatbuf,"route#%d",nexroutes); |
1c1a9fa1 |
471 | |
2ed30784 |
472 | eat_prefixmask(&carg,erwhatbuf, ",",0, &routeaddr,&routemask,0); |
473 | if (routemask == ~0UL) { |
474 | addrnet_mustdiffer(erwhatbuf,routeaddr,routemask, "local-addr",localaddr,~0UL); |
475 | addrnet_mustdiffer(erwhatbuf,routeaddr,routemask, "peer-addr",peeraddr,~0UL); |
476 | } |
477 | for (i=0; i<nexroutes; i++) { |
478 | sprintf(erwhatbuf2,"route#%d",i); |
479 | addrnet_mustdiffer(erwhatbuf,routeaddr,routemask, |
480 | erwhatbuf2,exroutes[i].prefix,exroutes[i].mask); |
481 | } |
482 | exroutes[nexroutes].prefix= routeaddr; |
483 | exroutes[nexroutes].mask= routemask; |
484 | exroutes[nexroutes].allow= 0; |
485 | ip2txt(routeaddr,exroutes[nexroutes].prefixtxt); |
486 | ip2txt(routemask,exroutes[nexroutes].masktxt); |
1c1a9fa1 |
487 | } |
1c1a9fa1 |
488 | } |
2ed30784 |
489 | |
1c1a9fa1 |
490 | ip2txt(localaddr,localtxt); |
491 | ip2txt(peeraddr,peertxt); |
1e963473 |
492 | } |
493 | |
494 | static void checkpermit(void) { |
495 | int i; |
496 | char erwhatbuf[100]; |
1c1a9fa1 |
497 | |
1e963473 |
498 | allallow= 1; |
499 | checkallow(localallow,"local-addr", localtxt,"32"); |
500 | checkallow(peerallow,"peer-addr", peertxt,"32"); |
501 | for (i=0; i<nexroutes; i++) { |
502 | sprintf(erwhatbuf, "route#%d", i); |
503 | checkallow(exroutes[i].allow, erwhatbuf, exroutes[i].prefixtxt, exroutes[i].masktxt); |
504 | } |
505 | if (!allallow) fatal("access denied"); |
506 | } |
507 | |
508 | static void dumpdebug(void) __attribute__((noreturn)); |
509 | static void dumpdebug(void) { |
510 | int i; |
511 | char erwhatbuf[100]; |
512 | |
513 | printf("protocol: debug\n" |
514 | "local: %08lx == %s\n" |
515 | "peer: %08lx == %s\n" |
516 | "mtu: %ld\n" |
517 | "routes: %d\n", |
518 | localaddr, localtxt, |
519 | peeraddr, peertxt, |
520 | mtu, |
521 | nexroutes); |
522 | for (i=0; i<nexroutes; i++) { |
523 | sprintf(erwhatbuf, "route#%d:", i); |
524 | printf("%-9s %08lx/%08lx == %s/%s\n", |
525 | erwhatbuf, |
526 | exroutes[i].prefix, exroutes[i].mask, |
527 | exroutes[i].prefixtxt, exroutes[i].masktxt); |
1c1a9fa1 |
528 | } |
1e963473 |
529 | if (ferror(stdout) || fclose(stdout)) sysfatal("flush stdout"); |
530 | exit(0); |
531 | } |
532 | |
6d360a53 |
533 | |
534 | static void setsigmask(const sigset_t *ss) { |
535 | int r; |
536 | |
537 | r= sigprocmask(SIG_SETMASK, ss, 0); |
538 | if (r) sysfatal("[un]block signals"); |
539 | } |
540 | |
02b2392d |
541 | static void setsignals(void (*handler)(int), struct sigaction *sa, int chldflags) { |
542 | const int *signalp; |
543 | int r, sig; |
544 | |
545 | sa->sa_handler= handler; |
546 | sa->sa_flags= 0; |
547 | for (signalp=signals; (sig=*signalp); signalp++) { |
548 | r= sigaction(sig, sa, 0); if (r) sysfatal("uncatch signal"); |
549 | } |
550 | sa->sa_flags= chldflags; |
551 | r= sigaction(SIGCHLD, sa, 0); if (r) sysfatal("uncatch children"); |
552 | } |
553 | |
02b2392d |
554 | static void infork(void) { |
555 | struct sigaction sa; |
556 | |
557 | memset(&pids,0,sizeof(pids)); |
558 | sigemptyset(&sa.sa_mask); |
559 | setsignals(SIG_DFL,&sa,0); |
560 | setsigmask(&emptyset); |
6d360a53 |
561 | undoslattach= 0; |
02b2392d |
562 | } |
563 | |
564 | static pid_t makesubproc(void (*entry)(void)) { |
565 | pid_t pid; |
566 | |
567 | pid= fork(); if (pid == (pid_t)-1) sysfatal("fork for subprocess"); |
568 | if (pid) return pid; |
569 | |
570 | infork(); |
571 | entry(); |
572 | abort(); |
573 | } |
574 | |
575 | static int task(void) { |
576 | pid_t pid; |
577 | |
578 | pid= fork(); |
6d360a53 |
579 | if (pid == (pid_t)-1) sysfatal("fork for task"); |
580 | if (!pid) { infork(); return 1; } |
02b2392d |
581 | |
582 | pids.byname.task= pid; |
583 | while (pids.byname.task) sigsuspend(&emptyset); |
584 | return 0; |
585 | } |
586 | |
6d360a53 |
587 | static void mdup2(int fd1, int fd2, const char *what) { |
588 | int r; |
589 | |
590 | for (;;) { |
591 | r= dup2(fd1,fd2); if (r==fd2) return; |
592 | if (r!=-1) fatal("dup2 in %s gave wrong answer %d instead of %d",what,r,fd2); |
593 | if (errno != EINTR) sysfatal("dup2 failed in %s",what); |
594 | } |
595 | } |
596 | |
02b2392d |
597 | static void sl_entry(void) { |
6d360a53 |
598 | mdup2(slpipe[1],1,"slattach child"); |
02b2392d |
599 | execlp("slattach", "slattach", "-v", "-L", "-p",proto, ptyname, (char*)0); |
600 | sysfatal("cannot exec slattach"); |
601 | } |
602 | |
603 | static void cin_entry(void) { |
6d360a53 |
604 | mdup2(ptmaster,1,"cat input child"); |
02b2392d |
605 | execlp("cat", "cat", (char*)0); |
606 | sysfatal("cannot exec cat input"); |
607 | } |
608 | |
609 | static void cout_entry(void) { |
6d360a53 |
610 | mdup2(ptmaster,0,"cat output child"); |
02b2392d |
611 | execlp("cat", "cat", (char*)0); |
612 | sysfatal("cannot exec cat output"); |
613 | } |
614 | |
615 | static void sighandler(int signum) { |
616 | pid_t pid; |
617 | int estatus, status; |
618 | const char *taskfail; |
619 | |
620 | estatus= 4; |
621 | |
622 | if (signum == SIGCHLD) { |
623 | for (;;) { |
624 | pid= waitpid(-1,&status,WNOHANG); |
625 | if (!pid || pid == (pid_t)-1) return; |
626 | |
627 | if (pid == pids.byname.task) { |
628 | pids.byname.task= 0; |
629 | if (!status) return; |
630 | taskfail= "task"; |
631 | } else if (pid == pids.byname.cin) { |
632 | pids.byname.cin= 0; |
633 | if (status) { |
634 | taskfail= "input cat"; |
635 | } else { |
636 | taskfail= 0; |
637 | estatus= 0; |
638 | } |
639 | } else if (pid == pids.byname.cout) { |
640 | pids.byname.cout= 0; |
641 | taskfail= "output cat"; |
642 | } else if (pid == pids.byname.sl) { |
643 | pids.byname.sl= 0; |
644 | taskfail= "slattach"; |
645 | } else { |
646 | continue; |
647 | } |
6d360a53 |
648 | break; |
02b2392d |
649 | } |
650 | if (taskfail) { |
6d360a53 |
651 | if (WIFEXITED(status)) { |
652 | fprintf(stderr, |
653 | "userv-ipif service: %s unexpectedly exited with exit status %d\n", |
654 | taskfail, WEXITSTATUS(status)); |
655 | } else if (WIFSIGNALED(status)) { |
656 | fprintf(stderr, |
657 | "userv-ipif service: %s unexpectedly killed by signal %s%s\n", |
658 | taskfail, strsignal(WTERMSIG(status)), |
659 | WCOREDUMP(status) ? " (core dumped)" : ""); |
660 | } else { |
661 | fprintf(stderr, "userv-ipif service: %s unexpectedly terminated" |
662 | " with unknown status code %d\n", taskfail, status); |
663 | } |
02b2392d |
664 | } |
665 | } else { |
666 | fprintf(stderr, |
667 | "userv-ipif service: received signal %d, terminating\n", |
668 | signum); |
669 | } |
670 | |
671 | terminate(estatus); |
672 | } |
673 | |
674 | static void startup(void) { |
675 | int r; |
676 | struct sigaction sa; |
677 | |
678 | sigfillset(&fullset); |
679 | sigemptyset(&emptyset); |
680 | |
681 | ptmaster= getpt(); if (ptmaster==-1) sysfatal("allocate pty master"); |
682 | r= grantpt(ptmaster); if (r) sysfatal("grab/grant pty slave"); |
683 | ptyname= ptsname(ptmaster); if (!ptyname) sysfatal("get pty slave name"); |
684 | r= chmod(ptyname,0600); if (r) sysfatal("chmod pty slave"); |
6d360a53 |
685 | r= unlockpt(ptmaster); if (r) sysfatal("unlock pty"); |
02b2392d |
686 | |
687 | sigfillset(&sa.sa_mask); |
688 | setsignals(sighandler,&sa,SA_NOCLDSTOP); |
689 | setsigmask(&fullset); |
690 | } |
691 | |
692 | static void startslattach(void) { |
6d360a53 |
693 | static char ifnbuf[200]; |
694 | |
02b2392d |
695 | FILE *piper; |
02b2392d |
696 | int r, l, k; |
697 | |
698 | r= pipe(slpipe); if (r) sysfatal("create pipe"); |
699 | piper= fdopen(slpipe[0],"r"); if (!piper) sysfatal("fdopen pipe"); |
700 | |
6d360a53 |
701 | undoslattach= 1; |
02b2392d |
702 | pids.byname.sl= makesubproc(sl_entry); |
703 | |
704 | close(slpipe[1]); |
705 | setsigmask(&emptyset); |
706 | if (!fgets(ifnbuf,sizeof(ifnbuf),piper)) { |
707 | if (ferror(piper)) sysfatal("cannot read ifname from slattach"); |
708 | else fatal("cannot read ifname from slattach"); |
709 | } |
710 | setsigmask(&fullset); |
711 | l= strlen(ifnbuf); |
2c310400 |
712 | if (l<=0 || ifnbuf[l-1] != '\n') fatal("slattach gave strange output `%s'",ifnbuf); |
02b2392d |
713 | ifnbuf[l-1]= 0; |
714 | for (k=l; k>0 && ifnbuf[k-1]!=' '; k--); |
715 | ifname= ifnbuf+k; |
716 | } |
717 | |
718 | static void netconfigure(void) { |
719 | char mtutxt[100]; |
720 | int i; |
721 | |
722 | if (task()) { |
723 | sprintf(mtutxt,"%lu",mtu); |
724 | |
725 | execlp("ifconfig", "ifconfig", ifname, localtxt, |
726 | "netmask","255.255.255.255", "-broadcast", "pointopoint",peertxt, |
727 | "mtu",mtutxt, "up", (char*)0); |
728 | sysfatal("cannot exec ifconfig"); |
729 | } |
730 | |
02b2392d |
731 | for (i=0; i<nexroutes; i++) { |
732 | if (task()) { |
6d360a53 |
733 | execlp("route","route", "add", "-net",exroutes[i].prefixtxt, |
02b2392d |
734 | "netmask",exroutes[i].masktxt, |
735 | "gw",peertxt, "dev",ifname, (char*)0); |
736 | sysfatal("cannot exec route (for route)"); |
737 | } |
738 | } |
739 | } |
740 | |
741 | static void copydata(void) __attribute__((noreturn)); |
5f1c67ff |
742 | static void copydata(void) { |
743 | int r; |
744 | |
02b2392d |
745 | pids.byname.cin= makesubproc(cin_entry); |
5f1c67ff |
746 | for (;;) { |
747 | r= write(1, "\300", 1); if (r==1) break; |
748 | assert(r==-1); if (errno != EINTR) sysfatal("send initial delim to confirm"); |
749 | } |
02b2392d |
750 | pids.byname.cout= makesubproc(cout_entry); |
751 | |
752 | for (;;) sigsuspend(&emptyset); |
753 | } |
754 | |
1e963473 |
755 | int main(int argc, const char *const *argv) { |
756 | parseargs(argc,argv); |
757 | pconfig(configstr,0); |
758 | checkpermit(); |
759 | if (!proto) dumpdebug(); |
760 | |
02b2392d |
761 | startup(); |
762 | startslattach(); |
763 | netconfigure(); |
764 | copydata(); |
1c1a9fa1 |
765 | } |