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