fix debug message
[oweals/busybox.git] / networking / ifupdown.c
1 /* vi: set sw=4 ts=4: */
2 /*
3  *  ifupdown for busybox
4  *  Copyright (c) 2002 Glenn McGrath
5  *  Copyright (c) 2003-2004 Erik Andersen <andersen@codepoet.org>
6  *
7  *  Based on ifupdown v 0.6.4 by Anthony Towns
8  *  Copyright (c) 1999 Anthony Towns <aj@azure.humbug.org.au>
9  *
10  *  Changes to upstream version
11  *  Remove checks for kernel version, assume kernel version 2.2.0 or better.
12  *  Lines in the interfaces file cannot wrap.
13  *  To adhere to the FHS, the default state file is /var/run/ifstate
14  *  (defined via CONFIG_IFUPDOWN_IFSTATE_PATH) and can be overridden by build
15  *  configuration.
16  *
17  * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
18  */
19
20 #include <sys/utsname.h>
21 #include <fnmatch.h>
22
23 #include "libbb.h"
24
25 #define MAX_OPT_DEPTH 10
26 #define EUNBALBRACK 10001
27 #define EUNDEFVAR   10002
28 #define EUNBALPER   10000
29
30 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
31 #define MAX_INTERFACE_LENGTH 10
32 #endif
33
34 #define UDHCPC_CMD_OPTIONS CONFIG_IFUPDOWN_UDHCPC_CMD_OPTIONS
35
36 #define debug_noise(args...) /*fprintf(stderr, args)*/
37
38 /* Forward declaration */
39 struct interface_defn_t;
40
41 typedef int execfn(char *command);
42
43 struct method_t {
44         const char *name;
45         int (*up)(struct interface_defn_t *ifd, execfn *e);
46         int (*down)(struct interface_defn_t *ifd, execfn *e);
47 };
48
49 struct address_family_t {
50         const char *name;
51         int n_methods;
52         const struct method_t *method;
53 };
54
55 struct mapping_defn_t {
56         struct mapping_defn_t *next;
57
58         int max_matches;
59         int n_matches;
60         char **match;
61
62         char *script;
63
64         int max_mappings;
65         int n_mappings;
66         char **mapping;
67 };
68
69 struct variable_t {
70         char *name;
71         char *value;
72 };
73
74 struct interface_defn_t {
75         const struct address_family_t *address_family;
76         const struct method_t *method;
77
78         char *iface;
79         int max_options;
80         int n_options;
81         struct variable_t *option;
82 };
83
84 struct interfaces_file_t {
85         llist_t *autointerfaces;
86         llist_t *ifaces;
87         struct mapping_defn_t *mappings;
88 };
89
90 #define OPTION_STR "anvf" IF_FEATURE_IFUPDOWN_MAPPING("m") "i:"
91 enum {
92         OPT_do_all = 0x1,
93         OPT_no_act = 0x2,
94         OPT_verbose = 0x4,
95         OPT_force = 0x8,
96         OPT_no_mappings = 0x10,
97 };
98 #define DO_ALL (option_mask32 & OPT_do_all)
99 #define NO_ACT (option_mask32 & OPT_no_act)
100 #define VERBOSE (option_mask32 & OPT_verbose)
101 #define FORCE (option_mask32 & OPT_force)
102 #define NO_MAPPINGS (option_mask32 & OPT_no_mappings)
103
104 static char **my_environ;
105
106 static const char *startup_PATH;
107
108 #if ENABLE_FEATURE_IFUPDOWN_IPV4 || ENABLE_FEATURE_IFUPDOWN_IPV6
109
110 static void addstr(char **bufp, const char *str, size_t str_length)
111 {
112         /* xasprintf trick will be smaller, but we are often
113          * called with str_length == 1 - don't want to have
114          * THAT much of malloc/freeing! */
115         char *buf = *bufp;
116         int len = (buf ? strlen(buf) : 0);
117         str_length++;
118         buf = xrealloc(buf, len + str_length);
119         /* copies at most str_length-1 chars! */
120         safe_strncpy(buf + len, str, str_length);
121         *bufp = buf;
122 }
123
124 static int strncmpz(const char *l, const char *r, size_t llen)
125 {
126         int i = strncmp(l, r, llen);
127
128         if (i == 0)
129                 return -r[llen];
130         return i;
131 }
132
133 static char *get_var(const char *id, size_t idlen, struct interface_defn_t *ifd)
134 {
135         int i;
136
137         if (strncmpz(id, "iface", idlen) == 0) {
138                 static char *label_buf;
139                 //char *result;
140
141                 free(label_buf);
142                 label_buf = xstrdup(ifd->iface);
143                 // Remove virtual iface suffix - why?
144                 // ubuntu's ifup doesn't do this
145                 //result = strchrnul(label_buf, ':');
146                 //*result = '\0';
147                 return label_buf;
148         }
149         if (strncmpz(id, "label", idlen) == 0) {
150                 return ifd->iface;
151         }
152         for (i = 0; i < ifd->n_options; i++) {
153                 if (strncmpz(id, ifd->option[i].name, idlen) == 0) {
154                         return ifd->option[i].value;
155                 }
156         }
157         return NULL;
158 }
159
160 #if ENABLE_FEATURE_IFUPDOWN_IP
161 static int count_netmask_bits(const char *dotted_quad)
162 {
163 //      int result;
164 //      unsigned a, b, c, d;
165 //      /* Found a netmask...  Check if it is dotted quad */
166 //      if (sscanf(dotted_quad, "%u.%u.%u.%u", &a, &b, &c, &d) != 4)
167 //              return -1;
168 //      if ((a|b|c|d) >> 8)
169 //              return -1; /* one of numbers is >= 256 */
170 //      d |= (a << 24) | (b << 16) | (c << 8); /* IP */
171 //      d = ~d; /* 11110000 -> 00001111 */
172
173         /* Shorter version */
174         int result;
175         struct in_addr ip;
176         unsigned d;
177
178         if (inet_aton(dotted_quad, &ip) == 0)
179                 return -1; /* malformed dotted IP */
180         d = ntohl(ip.s_addr); /* IP in host order */
181         d = ~d; /* 11110000 -> 00001111 */
182         if (d & (d+1)) /* check that it is in 00001111 form */
183                 return -1; /* no it is not */
184         result = 32;
185         while (d) {
186                 d >>= 1;
187                 result--;
188         }
189         return result;
190 }
191 #endif
192
193 static char *parse(const char *command, struct interface_defn_t *ifd)
194 {
195         size_t old_pos[MAX_OPT_DEPTH] = { 0 };
196         int okay[MAX_OPT_DEPTH] = { 1 };
197         int opt_depth = 1;
198         char *result = NULL;
199
200         while (*command) {
201                 switch (*command) {
202                 default:
203                         addstr(&result, command, 1);
204                         command++;
205                         break;
206                 case '\\':
207                         if (command[1]) {
208                                 addstr(&result, command + 1, 1);
209                                 command += 2;
210                         } else {
211                                 addstr(&result, command, 1);
212                                 command++;
213                         }
214                         break;
215                 case '[':
216                         if (command[1] == '[' && opt_depth < MAX_OPT_DEPTH) {
217                                 old_pos[opt_depth] = result ? strlen(result) : 0;
218                                 okay[opt_depth] = 1;
219                                 opt_depth++;
220                                 command += 2;
221                         } else {
222                                 addstr(&result, "[", 1);
223                                 command++;
224                         }
225                         break;
226                 case ']':
227                         if (command[1] == ']' && opt_depth > 1) {
228                                 opt_depth--;
229                                 if (!okay[opt_depth]) {
230                                         result[old_pos[opt_depth]] = '\0';
231                                 }
232                                 command += 2;
233                         } else {
234                                 addstr(&result, "]", 1);
235                                 command++;
236                         }
237                         break;
238                 case '%':
239                         {
240                                 char *nextpercent;
241                                 char *varvalue;
242
243                                 command++;
244                                 nextpercent = strchr(command, '%');
245                                 if (!nextpercent) {
246                                         errno = EUNBALPER;
247                                         free(result);
248                                         return NULL;
249                                 }
250
251                                 varvalue = get_var(command, nextpercent - command, ifd);
252
253                                 if (varvalue) {
254 #if ENABLE_FEATURE_IFUPDOWN_IP
255                                         /* "hwaddress <class> <address>":
256                                          * unlike ifconfig, ip doesnt want <class>
257                                          * (usually "ether" keyword). Skip it. */
258                                         if (strncmp(command, "hwaddress", 9) == 0) {
259                                                 varvalue = skip_whitespace(skip_non_whitespace(varvalue));
260                                         }
261 #endif
262                                         addstr(&result, varvalue, strlen(varvalue));
263                                 } else {
264 #if ENABLE_FEATURE_IFUPDOWN_IP
265                                         /* Sigh...  Add a special case for 'ip' to convert from
266                                          * dotted quad to bit count style netmasks.  */
267                                         if (strncmp(command, "bnmask", 6) == 0) {
268                                                 unsigned res;
269                                                 varvalue = get_var("netmask", 7, ifd);
270                                                 if (varvalue) {
271                                                         res = count_netmask_bits(varvalue);
272                                                         if (res > 0) {
273                                                                 const char *argument = utoa(res);
274                                                                 addstr(&result, argument, strlen(argument));
275                                                                 command = nextpercent + 1;
276                                                                 break;
277                                                         }
278                                                 }
279                                         }
280 #endif
281                                         okay[opt_depth - 1] = 0;
282                                 }
283
284                                 command = nextpercent + 1;
285                         }
286                         break;
287                 }
288         }
289
290         if (opt_depth > 1) {
291                 errno = EUNBALBRACK;
292                 free(result);
293                 return NULL;
294         }
295
296         if (!okay[0]) {
297                 errno = EUNDEFVAR;
298                 free(result);
299                 return NULL;
300         }
301
302         return result;
303 }
304
305 /* execute() returns 1 for success and 0 for failure */
306 static int execute(const char *command, struct interface_defn_t *ifd, execfn *exec)
307 {
308         char *out;
309         int ret;
310
311         out = parse(command, ifd);
312         if (!out) {
313                 /* parse error? */
314                 return 0;
315         }
316         /* out == "": parsed ok but not all needed variables known, skip */
317         ret = out[0] ? (*exec)(out) : 1;
318
319         free(out);
320         if (ret != 1) {
321                 return 0;
322         }
323         return 1;
324 }
325 #endif
326
327 #if ENABLE_FEATURE_IFUPDOWN_IPV6
328 static int loopback_up6(struct interface_defn_t *ifd, execfn *exec)
329 {
330 #if ENABLE_FEATURE_IFUPDOWN_IP
331         int result;
332         result = execute("ip addr add ::1 dev %iface%", ifd, exec);
333         result += execute("ip link set %iface% up", ifd, exec);
334         return ((result == 2) ? 2 : 0);
335 #else
336         return execute("ifconfig %iface% add ::1", ifd, exec);
337 #endif
338 }
339
340 static int loopback_down6(struct interface_defn_t *ifd, execfn *exec)
341 {
342 #if ENABLE_FEATURE_IFUPDOWN_IP
343         return execute("ip link set %iface% down", ifd, exec);
344 #else
345         return execute("ifconfig %iface% del ::1", ifd, exec);
346 #endif
347 }
348
349 static int static_up6(struct interface_defn_t *ifd, execfn *exec)
350 {
351         int result;
352 #if ENABLE_FEATURE_IFUPDOWN_IP
353         result = execute("ip addr add %address%/%netmask% dev %iface%[[ label %label%]]", ifd, exec);
354         result += execute("ip link set[[ mtu %mtu%]][[ addr %hwaddress%]] %iface% up", ifd, exec);
355         /* Was: "[[ ip ....%gateway% ]]". Removed extra spaces w/o checking */
356         result += execute("[[ip route add ::/0 via %gateway%]]", ifd, exec);
357 #else
358         result = execute("ifconfig %iface%[[ media %media%]][[ hw %hwaddress%]][[ mtu %mtu%]] up", ifd, exec);
359         result += execute("ifconfig %iface% add %address%/%netmask%", ifd, exec);
360         result += execute("[[route -A inet6 add ::/0 gw %gateway%]]", ifd, exec);
361 #endif
362         return ((result == 3) ? 3 : 0);
363 }
364
365 static int static_down6(struct interface_defn_t *ifd, execfn *exec)
366 {
367 #if ENABLE_FEATURE_IFUPDOWN_IP
368         return execute("ip link set %iface% down", ifd, exec);
369 #else
370         return execute("ifconfig %iface% down", ifd, exec);
371 #endif
372 }
373
374 #if ENABLE_FEATURE_IFUPDOWN_IP
375 static int v4tunnel_up(struct interface_defn_t *ifd, execfn *exec)
376 {
377         int result;
378         result = execute("ip tunnel add %iface% mode sit remote "
379                         "%endpoint%[[ local %local%]][[ ttl %ttl%]]", ifd, exec);
380         result += execute("ip link set %iface% up", ifd, exec);
381         result += execute("ip addr add %address%/%netmask% dev %iface%", ifd, exec);
382         result += execute("[[ip route add ::/0 via %gateway%]]", ifd, exec);
383         return ((result == 4) ? 4 : 0);
384 }
385
386 static int v4tunnel_down(struct interface_defn_t * ifd, execfn * exec)
387 {
388         return execute("ip tunnel del %iface%", ifd, exec);
389 }
390 #endif
391
392 static const struct method_t methods6[] = {
393 #if ENABLE_FEATURE_IFUPDOWN_IP
394         { "v4tunnel", v4tunnel_up, v4tunnel_down, },
395 #endif
396         { "static", static_up6, static_down6, },
397         { "loopback", loopback_up6, loopback_down6, },
398 };
399
400 static const struct address_family_t addr_inet6 = {
401         "inet6",
402         ARRAY_SIZE(methods6),
403         methods6
404 };
405 #endif /* FEATURE_IFUPDOWN_IPV6 */
406
407 #if ENABLE_FEATURE_IFUPDOWN_IPV4
408 static int loopback_up(struct interface_defn_t *ifd, execfn *exec)
409 {
410 #if ENABLE_FEATURE_IFUPDOWN_IP
411         int result;
412         result = execute("ip addr add 127.0.0.1/8 dev %iface%", ifd, exec);
413         result += execute("ip link set %iface% up", ifd, exec);
414         return ((result == 2) ? 2 : 0);
415 #else
416         return execute("ifconfig %iface% 127.0.0.1 up", ifd, exec);
417 #endif
418 }
419
420 static int loopback_down(struct interface_defn_t *ifd, execfn *exec)
421 {
422 #if ENABLE_FEATURE_IFUPDOWN_IP
423         int result;
424         result = execute("ip addr flush dev %iface%", ifd, exec);
425         result += execute("ip link set %iface% down", ifd, exec);
426         return ((result == 2) ? 2 : 0);
427 #else
428         return execute("ifconfig %iface% 127.0.0.1 down", ifd, exec);
429 #endif
430 }
431
432 static int static_up(struct interface_defn_t *ifd, execfn *exec)
433 {
434         int result;
435 #if ENABLE_FEATURE_IFUPDOWN_IP
436         result = execute("ip addr add %address%/%bnmask%[[ broadcast %broadcast%]] "
437                         "dev %iface%[[ peer %pointopoint%]][[ label %label%]]", ifd, exec);
438         result += execute("ip link set[[ mtu %mtu%]][[ addr %hwaddress%]] %iface% up", ifd, exec);
439         result += execute("[[ip route add default via %gateway% dev %iface%]]", ifd, exec);
440         return ((result == 3) ? 3 : 0);
441 #else
442         /* ifconfig said to set iface up before it processes hw %hwaddress%,
443          * which then of course fails. Thus we run two separate ifconfig */
444         result = execute("ifconfig %iface%[[ hw %hwaddress%]][[ media %media%]][[ mtu %mtu%]] up",
445                                 ifd, exec);
446         result += execute("ifconfig %iface% %address% netmask %netmask%"
447                                 "[[ broadcast %broadcast%]][[ pointopoint %pointopoint%]] ",
448                                 ifd, exec);
449         result += execute("[[route add default gw %gateway% %iface%]]", ifd, exec);
450         return ((result == 3) ? 3 : 0);
451 #endif
452 }
453
454 static int static_down(struct interface_defn_t *ifd, execfn *exec)
455 {
456         int result;
457 #if ENABLE_FEATURE_IFUPDOWN_IP
458         result = execute("ip addr flush dev %iface%", ifd, exec);
459         result += execute("ip link set %iface% down", ifd, exec);
460 #else
461         /* result = execute("[[route del default gw %gateway% %iface%]]", ifd, exec); */
462         /* Bringing the interface down deletes the routes in itself.
463            Otherwise this fails if we reference 'gateway' when using this from dhcp_down */
464         result = 1;
465         result += execute("ifconfig %iface% down", ifd, exec);
466 #endif
467         return ((result == 2) ? 2 : 0);
468 }
469
470 #if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
471 struct dhcp_client_t
472 {
473         const char *name;
474         const char *startcmd;
475         const char *stopcmd;
476 };
477
478 static const struct dhcp_client_t ext_dhcp_clients[] = {
479         { "dhcpcd",
480                 "dhcpcd[[ -h %hostname%]][[ -i %vendor%]][[ -I %clientid%]][[ -l %leasetime%]] %iface%",
481                 "dhcpcd -k %iface%",
482         },
483         { "dhclient",
484                 "dhclient -pf /var/run/dhclient.%iface%.pid %iface%",
485                 "kill -9 `cat /var/run/dhclient.%iface%.pid` 2>/dev/null",
486         },
487         { "pump",
488                 "pump -i %iface%[[ -h %hostname%]][[ -l %leasehours%]]",
489                 "pump -i %iface% -k",
490         },
491         { "udhcpc",
492                 "udhcpc " UDHCPC_CMD_OPTIONS " -p /var/run/udhcpc.%iface%.pid -i %iface%[[ -H %hostname%]][[ -c %clientid%]]"
493                                 "[[ -s %script%]][[ %udhcpc_opts%]]",
494                 "kill `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null",
495         },
496 };
497 #endif /* ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCPC */
498
499 #if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
500 static int dhcp_up(struct interface_defn_t *ifd, execfn *exec)
501 {
502         unsigned i;
503 #if ENABLE_FEATURE_IFUPDOWN_IP
504         /* ip doesn't up iface when it configures it (unlike ifconfig) */
505         if (!execute("ip link set[[ addr %hwaddress%]] %iface% up", ifd, exec))
506                 return 0;
507 #else
508         /* needed if we have hwaddress on dhcp iface */
509         if (!execute("ifconfig %iface%[[ hw %hwaddress%]] up", ifd, exec))
510                 return 0;
511 #endif
512         for (i = 0; i < ARRAY_SIZE(ext_dhcp_clients); i++) {
513                 if (exists_execable(ext_dhcp_clients[i].name))
514                         return execute(ext_dhcp_clients[i].startcmd, ifd, exec);
515         }
516         bb_error_msg("no dhcp clients found");
517         return 0;
518 }
519 #elif ENABLE_APP_UDHCPC
520 static int dhcp_up(struct interface_defn_t *ifd, execfn *exec)
521 {
522 #if ENABLE_FEATURE_IFUPDOWN_IP
523         /* ip doesn't up iface when it configures it (unlike ifconfig) */
524         if (!execute("ip link set[[ addr %hwaddress%]] %iface% up", ifd, exec))
525                 return 0;
526 #else
527         /* needed if we have hwaddress on dhcp iface */
528         if (!execute("ifconfig %iface%[[ hw %hwaddress%]] up", ifd, exec))
529                 return 0;
530 #endif
531         return execute("udhcpc " UDHCPC_CMD_OPTIONS " -p /var/run/udhcpc.%iface%.pid "
532                         "-i %iface%[[ -H %hostname%]][[ -c %clientid%]][[ -s %script%]][[ %udhcpc_opts%]]",
533                         ifd, exec);
534 }
535 #else
536 static int dhcp_up(struct interface_defn_t *ifd UNUSED_PARAM,
537                 execfn *exec UNUSED_PARAM)
538 {
539         return 0; /* no dhcp support */
540 }
541 #endif
542
543 #if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
544 static int dhcp_down(struct interface_defn_t *ifd, execfn *exec)
545 {
546         int result = 0;
547         unsigned i;
548
549         for (i = 0; i < ARRAY_SIZE(ext_dhcp_clients); i++) {
550                 if (exists_execable(ext_dhcp_clients[i].name)) {
551                         result += execute(ext_dhcp_clients[i].stopcmd, ifd, exec);
552                         if (result)
553                                 break;
554                 }
555         }
556
557         if (!result)
558                 bb_error_msg("warning: no dhcp clients found and stopped");
559
560         /* Sleep a bit, otherwise static_down tries to bring down interface too soon,
561            and it may come back up because udhcpc is still shutting down */
562         usleep(100000);
563         result += static_down(ifd, exec);
564         return ((result == 3) ? 3 : 0);
565 }
566 #elif ENABLE_APP_UDHCPC
567 static int dhcp_down(struct interface_defn_t *ifd, execfn *exec)
568 {
569         int result;
570         result = execute("kill "
571                        "`cat /var/run/udhcpc.%iface%.pid` 2>/dev/null", ifd, exec);
572         /* Also bring the hardware interface down since
573            killing the dhcp client alone doesn't do it.
574            This enables consecutive ifup->ifdown->ifup */
575         /* Sleep a bit, otherwise static_down tries to bring down interface too soon,
576            and it may come back up because udhcpc is still shutting down */
577         usleep(100000);
578         result += static_down(ifd, exec);
579         return ((result == 3) ? 3 : 0);
580 }
581 #else
582 static int dhcp_down(struct interface_defn_t *ifd UNUSED_PARAM,
583                 execfn *exec UNUSED_PARAM)
584 {
585         return 0; /* no dhcp support */
586 }
587 #endif
588
589 static int manual_up_down(struct interface_defn_t *ifd UNUSED_PARAM, execfn *exec UNUSED_PARAM)
590 {
591         return 1;
592 }
593
594 static int bootp_up(struct interface_defn_t *ifd, execfn *exec)
595 {
596         return execute("bootpc[[ --bootfile %bootfile%]] --dev %iface%"
597                         "[[ --server %server%]][[ --hwaddr %hwaddr%]]"
598                         " --returniffail --serverbcast", ifd, exec);
599 }
600
601 static int ppp_up(struct interface_defn_t *ifd, execfn *exec)
602 {
603         return execute("pon[[ %provider%]]", ifd, exec);
604 }
605
606 static int ppp_down(struct interface_defn_t *ifd, execfn *exec)
607 {
608         return execute("poff[[ %provider%]]", ifd, exec);
609 }
610
611 static int wvdial_up(struct interface_defn_t *ifd, execfn *exec)
612 {
613         return execute("start-stop-daemon --start -x wvdial "
614                 "-p /var/run/wvdial.%iface% -b -m --[[ %provider%]]", ifd, exec);
615 }
616
617 static int wvdial_down(struct interface_defn_t *ifd, execfn *exec)
618 {
619         return execute("start-stop-daemon --stop -x wvdial "
620                         "-p /var/run/wvdial.%iface% -s 2", ifd, exec);
621 }
622
623 static const struct method_t methods[] = {
624         { "manual", manual_up_down, manual_up_down, },
625         { "wvdial", wvdial_up, wvdial_down, },
626         { "ppp", ppp_up, ppp_down, },
627         { "static", static_up, static_down, },
628         { "bootp", bootp_up, static_down, },
629         { "dhcp", dhcp_up, dhcp_down, },
630         { "loopback", loopback_up, loopback_down, },
631 };
632
633 static const struct address_family_t addr_inet = {
634         "inet",
635         ARRAY_SIZE(methods),
636         methods
637 };
638
639 #endif  /* if ENABLE_FEATURE_IFUPDOWN_IPV4 */
640
641 static char *next_word(char **buf)
642 {
643         unsigned length;
644         char *word;
645
646         /* Skip over leading whitespace */
647         word = skip_whitespace(*buf);
648
649         /* Stop on EOL */
650         if (*word == '\0')
651                 return NULL;
652
653         /* Find the length of this word (can't be 0) */
654         length = strcspn(word, " \t\n");
655
656         /* Unless we are already at NUL, store NUL and advance */
657         if (word[length] != '\0')
658                 word[length++] = '\0';
659
660         *buf = word + length;
661
662         return word;
663 }
664
665 static const struct address_family_t *get_address_family(const struct address_family_t *const af[], char *name)
666 {
667         int i;
668
669         if (!name)
670                 return NULL;
671
672         for (i = 0; af[i]; i++) {
673                 if (strcmp(af[i]->name, name) == 0) {
674                         return af[i];
675                 }
676         }
677         return NULL;
678 }
679
680 static const struct method_t *get_method(const struct address_family_t *af, char *name)
681 {
682         int i;
683
684         if (!name)
685                 return NULL;
686         /* TODO: use index_in_str_array() */
687         for (i = 0; i < af->n_methods; i++) {
688                 if (strcmp(af->method[i].name, name) == 0) {
689                         return &af->method[i];
690                 }
691         }
692         return NULL;
693 }
694
695 static struct interfaces_file_t *read_interfaces(const char *filename)
696 {
697         /* Let's try to be compatible.
698          *
699          * "man 5 interfaces" says:
700          * Lines starting with "#" are ignored. Note that end-of-line
701          * comments are NOT supported, comments must be on a line of their own.
702          * A line may be extended across multiple lines by making
703          * the last character a backslash.
704          *
705          * Seen elsewhere in example config file:
706          * A first non-blank "#" character makes the rest of the line
707          * be ignored. Blank lines are ignored. Lines may be indented freely.
708          * A "\" character at the very end of the line indicates the next line
709          * should be treated as a continuation of the current one.
710          */
711 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
712         struct mapping_defn_t *currmap = NULL;
713 #endif
714         struct interface_defn_t *currif = NULL;
715         struct interfaces_file_t *defn;
716         FILE *f;
717         char *buf;
718         char *first_word;
719         char *rest_of_line;
720         enum { NONE, IFACE, MAPPING } currently_processing = NONE;
721
722         defn = xzalloc(sizeof(*defn));
723         f = xfopen_for_read(filename);
724
725         while ((buf = xmalloc_fgetline(f)) != NULL) {
726 #if ENABLE_DESKTOP
727                 /* Trailing "\" concatenates lines */
728                 char *p;
729                 while ((p = last_char_is(buf, '\\')) != NULL) {
730                         *p = '\0';
731                         rest_of_line = xmalloc_fgetline(f);
732                         if (!rest_of_line)
733                                 break;
734                         p = xasprintf("%s%s", buf, rest_of_line);
735                         free(buf);
736                         free(rest_of_line);
737                         buf = p;
738                 }
739 #endif
740                 rest_of_line = buf;
741                 first_word = next_word(&rest_of_line);
742                 if (!first_word || *first_word == '#') {
743                         free(buf);
744                         continue; /* blank/comment line */
745                 }
746
747                 if (strcmp(first_word, "mapping") == 0) {
748 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
749                         currmap = xzalloc(sizeof(*currmap));
750
751                         while ((first_word = next_word(&rest_of_line)) != NULL) {
752                                 currmap->match = xrealloc_vector(currmap->match, 4, currmap->n_matches);
753                                 currmap->match[currmap->n_matches++] = xstrdup(first_word);
754                         }
755                         /*currmap->max_mappings = 0; - done by xzalloc */
756                         /*currmap->n_mappings = 0;*/
757                         /*currmap->mapping = NULL;*/
758                         /*currmap->script = NULL;*/
759                         {
760                                 struct mapping_defn_t **where = &defn->mappings;
761                                 while (*where != NULL) {
762                                         where = &(*where)->next;
763                                 }
764                                 *where = currmap;
765                                 /*currmap->next = NULL;*/
766                         }
767                         debug_noise("Added mapping\n");
768 #endif
769                         currently_processing = MAPPING;
770                 } else if (strcmp(first_word, "iface") == 0) {
771                         static const struct address_family_t *const addr_fams[] = {
772 #if ENABLE_FEATURE_IFUPDOWN_IPV4
773                                 &addr_inet,
774 #endif
775 #if ENABLE_FEATURE_IFUPDOWN_IPV6
776                                 &addr_inet6,
777 #endif
778                                 NULL
779                         };
780                         char *iface_name;
781                         char *address_family_name;
782                         char *method_name;
783                         llist_t *iface_list;
784
785                         currif = xzalloc(sizeof(*currif));
786                         iface_name = next_word(&rest_of_line);
787                         address_family_name = next_word(&rest_of_line);
788                         method_name = next_word(&rest_of_line);
789
790                         if (method_name == NULL)
791                                 bb_error_msg_and_die("too few parameters for line \"%s\"", buf);
792
793                         /* ship any trailing whitespace */
794                         rest_of_line = skip_whitespace(rest_of_line);
795
796                         if (rest_of_line[0] != '\0' /* && rest_of_line[0] != '#' */)
797                                 bb_error_msg_and_die("too many parameters \"%s\"", buf);
798
799                         currif->iface = xstrdup(iface_name);
800
801                         currif->address_family = get_address_family(addr_fams, address_family_name);
802                         if (!currif->address_family)
803                                 bb_error_msg_and_die("unknown address type \"%s\"", address_family_name);
804
805                         currif->method = get_method(currif->address_family, method_name);
806                         if (!currif->method)
807                                 bb_error_msg_and_die("unknown method \"%s\"", method_name);
808
809                         for (iface_list = defn->ifaces; iface_list; iface_list = iface_list->link) {
810                                 struct interface_defn_t *tmp = (struct interface_defn_t *) iface_list->data;
811                                 if ((strcmp(tmp->iface, currif->iface) == 0)
812                                  && (tmp->address_family == currif->address_family)
813                                 ) {
814                                         bb_error_msg_and_die("duplicate interface \"%s\"", tmp->iface);
815                                 }
816                         }
817                         llist_add_to_end(&(defn->ifaces), (char*)currif);
818
819                         debug_noise("iface %s %s %s\n", currif->iface, address_family_name, method_name);
820                         currently_processing = IFACE;
821                 } else if (strcmp(first_word, "auto") == 0) {
822                         while ((first_word = next_word(&rest_of_line)) != NULL) {
823
824                                 /* Check the interface isnt already listed */
825                                 if (llist_find_str(defn->autointerfaces, first_word)) {
826                                         bb_perror_msg_and_die("interface declared auto twice \"%s\"", buf);
827                                 }
828
829                                 /* Add the interface to the list */
830                                 llist_add_to_end(&(defn->autointerfaces), xstrdup(first_word));
831                                 debug_noise("\nauto %s\n", first_word);
832                         }
833                         currently_processing = NONE;
834                 } else {
835                         switch (currently_processing) {
836                         case IFACE:
837                                 if (rest_of_line[0] == '\0')
838                                         bb_error_msg_and_die("option with empty value \"%s\"", buf);
839
840                                 if (strcmp(first_word, "up") != 0
841                                  && strcmp(first_word, "down") != 0
842                                  && strcmp(first_word, "pre-up") != 0
843                                  && strcmp(first_word, "post-down") != 0
844                                 ) {
845                                         int i;
846                                         for (i = 0; i < currif->n_options; i++) {
847                                                 if (strcmp(currif->option[i].name, first_word) == 0)
848                                                         bb_error_msg_and_die("duplicate option \"%s\"", buf);
849                                         }
850                                 }
851                                 if (currif->n_options >= currif->max_options) {
852                                         currif->max_options += 10;
853                                         currif->option = xrealloc(currif->option,
854                                                 sizeof(*currif->option) * currif->max_options);
855                                 }
856                                 debug_noise("\t%s=%s\n", first_word, rest_of_line);
857                                 currif->option[currif->n_options].name = xstrdup(first_word);
858                                 currif->option[currif->n_options].value = xstrdup(rest_of_line);
859                                 currif->n_options++;
860                                 break;
861                         case MAPPING:
862 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
863                                 if (strcmp(first_word, "script") == 0) {
864                                         if (currmap->script != NULL)
865                                                 bb_error_msg_and_die("duplicate script in mapping \"%s\"", buf);
866                                         currmap->script = xstrdup(next_word(&rest_of_line));
867                                 } else if (strcmp(first_word, "map") == 0) {
868                                         if (currmap->n_mappings >= currmap->max_mappings) {
869                                                 currmap->max_mappings = currmap->max_mappings * 2 + 1;
870                                                 currmap->mapping = xrealloc(currmap->mapping,
871                                                         sizeof(char *) * currmap->max_mappings);
872                                         }
873                                         currmap->mapping[currmap->n_mappings] = xstrdup(next_word(&rest_of_line));
874                                         currmap->n_mappings++;
875                                 } else {
876                                         bb_error_msg_and_die("misplaced option \"%s\"", buf);
877                                 }
878 #endif
879                                 break;
880                         case NONE:
881                         default:
882                                 bb_error_msg_and_die("misplaced option \"%s\"", buf);
883                         }
884                 }
885                 free(buf);
886         } /* while (fgets) */
887
888         if (ferror(f) != 0) {
889                 /* ferror does NOT set errno! */
890                 bb_error_msg_and_die("%s: I/O error", filename);
891         }
892         fclose(f);
893
894         return defn;
895 }
896
897 static char *setlocalenv(const char *format, const char *name, const char *value)
898 {
899         char *result;
900         char *here;
901         char *there;
902
903         result = xasprintf(format, name, value);
904
905         for (here = there = result; *there != '=' && *there; there++) {
906                 if (*there == '-')
907                         *there = '_';
908                 if (isalpha(*there))
909                         *there = toupper(*there);
910
911                 if (isalnum(*there) || *there == '_') {
912                         *here = *there;
913                         here++;
914                 }
915         }
916         memmove(here, there, strlen(there) + 1);
917
918         return result;
919 }
920
921 static void set_environ(struct interface_defn_t *iface, const char *mode)
922 {
923         char **environend;
924         int i;
925         const int n_env_entries = iface->n_options + 5;
926         char **ppch;
927
928         if (my_environ != NULL) {
929                 for (ppch = my_environ; *ppch; ppch++) {
930                         free(*ppch);
931                         *ppch = NULL;
932                 }
933                 free(my_environ);
934         }
935         my_environ = xzalloc(sizeof(char *) * (n_env_entries + 1 /* for final NULL */ ));
936         environend = my_environ;
937
938         for (i = 0; i < iface->n_options; i++) {
939                 if (strcmp(iface->option[i].name, "up") == 0
940                  || strcmp(iface->option[i].name, "down") == 0
941                  || strcmp(iface->option[i].name, "pre-up") == 0
942                  || strcmp(iface->option[i].name, "post-down") == 0
943                 ) {
944                         continue;
945                 }
946                 *(environend++) = setlocalenv("IF_%s=%s", iface->option[i].name, iface->option[i].value);
947         }
948
949         *(environend++) = setlocalenv("%s=%s", "IFACE", iface->iface);
950         *(environend++) = setlocalenv("%s=%s", "ADDRFAM", iface->address_family->name);
951         *(environend++) = setlocalenv("%s=%s", "METHOD", iface->method->name);
952         *(environend++) = setlocalenv("%s=%s", "MODE", mode);
953         *(environend++) = setlocalenv("%s=%s", "PATH", startup_PATH);
954 }
955
956 static int doit(char *str)
957 {
958         if (option_mask32 & (OPT_no_act|OPT_verbose)) {
959                 puts(str);
960         }
961         if (!(option_mask32 & OPT_no_act)) {
962                 pid_t child;
963                 int status;
964
965                 fflush(NULL);
966                 child = vfork();
967                 switch (child) {
968                 case -1: /* failure */
969                         return 0;
970                 case 0: /* child */
971                         execle(DEFAULT_SHELL, DEFAULT_SHELL, "-c", str, (char *) NULL, my_environ);
972                         _exit(127);
973                 }
974                 safe_waitpid(child, &status, 0);
975                 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
976                         return 0;
977                 }
978         }
979         return 1;
980 }
981
982 static int execute_all(struct interface_defn_t *ifd, const char *opt)
983 {
984         int i;
985         char *buf;
986         for (i = 0; i < ifd->n_options; i++) {
987                 if (strcmp(ifd->option[i].name, opt) == 0) {
988                         if (!doit(ifd->option[i].value)) {
989                                 return 0;
990                         }
991                 }
992         }
993
994         buf = xasprintf("run-parts /etc/network/if-%s.d", opt);
995         /* heh, we don't bother free'ing it */
996         return doit(buf);
997 }
998
999 static int check(char *str)
1000 {
1001         return str != NULL;
1002 }
1003
1004 static int iface_up(struct interface_defn_t *iface)
1005 {
1006         if (!iface->method->up(iface, check)) return -1;
1007         set_environ(iface, "start");
1008         if (!execute_all(iface, "pre-up")) return 0;
1009         if (!iface->method->up(iface, doit)) return 0;
1010         if (!execute_all(iface, "up")) return 0;
1011         return 1;
1012 }
1013
1014 static int iface_down(struct interface_defn_t *iface)
1015 {
1016         if (!iface->method->down(iface,check)) return -1;
1017         set_environ(iface, "stop");
1018         if (!execute_all(iface, "down")) return 0;
1019         if (!iface->method->down(iface, doit)) return 0;
1020         if (!execute_all(iface, "post-down")) return 0;
1021         return 1;
1022 }
1023
1024 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
1025 static int popen2(FILE **in, FILE **out, char *command, char *param)
1026 {
1027         char *argv[3] = { command, param, NULL };
1028         struct fd_pair infd, outfd;
1029         pid_t pid;
1030
1031         xpiped_pair(infd);
1032         xpiped_pair(outfd);
1033
1034         fflush(NULL);
1035         pid = vfork();
1036
1037         switch (pid) {
1038         case -1:  /* failure */
1039                 bb_perror_msg_and_die("vfork");
1040         case 0:  /* child */
1041                 /* NB: close _first_, then move fds! */
1042                 close(infd.wr);
1043                 close(outfd.rd);
1044                 xmove_fd(infd.rd, 0);
1045                 xmove_fd(outfd.wr, 1);
1046                 BB_EXECVP(command, argv);
1047                 _exit(127);
1048         }
1049         /* parent */
1050         close(infd.rd);
1051         close(outfd.wr);
1052         *in = fdopen(infd.wr, "w");
1053         *out = fdopen(outfd.rd, "r");
1054         return pid;
1055 }
1056
1057 static char *run_mapping(char *physical, struct mapping_defn_t *map)
1058 {
1059         FILE *in, *out;
1060         int i, status;
1061         pid_t pid;
1062
1063         char *logical = xstrdup(physical);
1064
1065         /* Run the mapping script. Never fails. */
1066         pid = popen2(&in, &out, map->script, physical);
1067
1068         /* Write mappings to stdin of mapping script. */
1069         for (i = 0; i < map->n_mappings; i++) {
1070                 fprintf(in, "%s\n", map->mapping[i]);
1071         }
1072         fclose(in);
1073         safe_waitpid(pid, &status, 0);
1074
1075         if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
1076                 /* If the mapping script exited successfully, try to
1077                  * grab a line of output and use that as the name of the
1078                  * logical interface. */
1079                 char *new_logical = xmalloc_fgetline(out);
1080
1081                 if (new_logical) {
1082                         /* If we are able to read a line of output from the script,
1083                          * remove any trailing whitespace and use this value
1084                          * as the name of the logical interface. */
1085                         char *pch = new_logical + strlen(new_logical) - 1;
1086
1087                         while (pch >= new_logical && isspace(*pch))
1088                                 *(pch--) = '\0';
1089
1090                         free(logical);
1091                         logical = new_logical;
1092                 }
1093         }
1094
1095         fclose(out);
1096
1097         return logical;
1098 }
1099 #endif /* FEATURE_IFUPDOWN_MAPPING */
1100
1101 static llist_t *find_iface_state(llist_t *state_list, const char *iface)
1102 {
1103         unsigned iface_len = strlen(iface);
1104         llist_t *search = state_list;
1105
1106         while (search) {
1107                 if ((strncmp(search->data, iface, iface_len) == 0)
1108                  && (search->data[iface_len] == '=')
1109                 ) {
1110                         return search;
1111                 }
1112                 search = search->link;
1113         }
1114         return NULL;
1115 }
1116
1117 /* read the previous state from the state file */
1118 static llist_t *read_iface_state(void)
1119 {
1120         llist_t *state_list = NULL;
1121         FILE *state_fp = fopen_for_read(CONFIG_IFUPDOWN_IFSTATE_PATH);
1122
1123         if (state_fp) {
1124                 char *start, *end_ptr;
1125                 while ((start = xmalloc_fgets(state_fp)) != NULL) {
1126                         /* We should only need to check for a single character */
1127                         end_ptr = start + strcspn(start, " \t\n");
1128                         *end_ptr = '\0';
1129                         llist_add_to(&state_list, start);
1130                 }
1131                 fclose(state_fp);
1132         }
1133         return state_list;
1134 }
1135
1136
1137 int ifupdown_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1138 int ifupdown_main(int argc, char **argv)
1139 {
1140         int (*cmds)(struct interface_defn_t *);
1141         struct interfaces_file_t *defn;
1142         llist_t *target_list = NULL;
1143         const char *interfaces = "/etc/network/interfaces";
1144         bool any_failures = 0;
1145
1146         cmds = iface_down;
1147         if (applet_name[2] == 'u') {
1148                 /* ifup command */
1149                 cmds = iface_up;
1150         }
1151
1152         getopt32(argv, OPTION_STR, &interfaces);
1153         if (argc - optind > 0) {
1154                 if (DO_ALL) bb_show_usage();
1155         } else {
1156                 if (!DO_ALL) bb_show_usage();
1157         }
1158
1159         debug_noise("reading %s file:\n", interfaces);
1160         defn = read_interfaces(interfaces);
1161         debug_noise("\ndone reading %s\n\n", interfaces);
1162
1163         startup_PATH = getenv("PATH");
1164         if (!startup_PATH) startup_PATH = "";
1165
1166         /* Create a list of interfaces to work on */
1167         if (DO_ALL) {
1168                 target_list = defn->autointerfaces;
1169         } else {
1170                 llist_add_to_end(&target_list, argv[optind]);
1171         }
1172
1173         /* Update the interfaces */
1174         while (target_list) {
1175                 llist_t *iface_list;
1176                 struct interface_defn_t *currif;
1177                 char *iface;
1178                 char *liface;
1179                 char *pch;
1180                 bool okay = 0;
1181                 int cmds_ret;
1182
1183                 iface = xstrdup(target_list->data);
1184                 target_list = target_list->link;
1185
1186                 pch = strchr(iface, '=');
1187                 if (pch) {
1188                         *pch = '\0';
1189                         liface = xstrdup(pch + 1);
1190                 } else {
1191                         liface = xstrdup(iface);
1192                 }
1193
1194                 if (!FORCE) {
1195                         llist_t *state_list = read_iface_state();
1196                         const llist_t *iface_state = find_iface_state(state_list, iface);
1197
1198                         if (cmds == iface_up) {
1199                                 /* ifup */
1200                                 if (iface_state) {
1201                                         bb_error_msg("interface %s already configured", iface);
1202                                         continue;
1203                                 }
1204                         } else {
1205                                 /* ifdown */
1206                                 if (!iface_state) {
1207                                         bb_error_msg("interface %s not configured", iface);
1208                                         continue;
1209                                 }
1210                         }
1211                         llist_free(state_list, free);
1212                 }
1213
1214 #if ENABLE_FEATURE_IFUPDOWN_MAPPING
1215                 if ((cmds == iface_up) && !NO_MAPPINGS) {
1216                         struct mapping_defn_t *currmap;
1217
1218                         for (currmap = defn->mappings; currmap; currmap = currmap->next) {
1219                                 int i;
1220                                 for (i = 0; i < currmap->n_matches; i++) {
1221                                         if (fnmatch(currmap->match[i], liface, 0) != 0)
1222                                                 continue;
1223                                         if (VERBOSE) {
1224                                                 printf("Running mapping script %s on %s\n", currmap->script, liface);
1225                                         }
1226                                         liface = run_mapping(iface, currmap);
1227                                         break;
1228                                 }
1229                         }
1230                 }
1231 #endif
1232
1233                 iface_list = defn->ifaces;
1234                 while (iface_list) {
1235                         currif = (struct interface_defn_t *) iface_list->data;
1236                         if (strcmp(liface, currif->iface) == 0) {
1237                                 char *oldiface = currif->iface;
1238
1239                                 okay = 1;
1240                                 currif->iface = iface;
1241
1242                                 debug_noise("\nConfiguring interface %s (%s)\n", liface, currif->address_family->name);
1243
1244                                 /* Call the cmds function pointer, does either iface_up() or iface_down() */
1245                                 cmds_ret = cmds(currif);
1246                                 if (cmds_ret == -1) {
1247                                         bb_error_msg("don't seem to have all the variables for %s/%s",
1248                                                         liface, currif->address_family->name);
1249                                         any_failures = 1;
1250                                 } else if (cmds_ret == 0) {
1251                                         any_failures = 1;
1252                                 }
1253
1254                                 currif->iface = oldiface;
1255                         }
1256                         iface_list = iface_list->link;
1257                 }
1258                 if (VERBOSE) {
1259                         bb_putchar('\n');
1260                 }
1261
1262                 if (!okay && !FORCE) {
1263                         bb_error_msg("ignoring unknown interface %s", liface);
1264                         any_failures = 1;
1265                 } else if (!NO_ACT) {
1266                         /* update the state file */
1267                         FILE *state_fp;
1268                         llist_t *state;
1269                         llist_t *state_list = read_iface_state();
1270                         llist_t *iface_state = find_iface_state(state_list, iface);
1271
1272                         if (cmds == iface_up) {
1273                                 char * const newiface = xasprintf("%s=%s", iface, liface);
1274                                 if (iface_state == NULL) {
1275                                         llist_add_to_end(&state_list, newiface);
1276                                 } else {
1277                                         free(iface_state->data);
1278                                         iface_state->data = newiface;
1279                                 }
1280                         } else {
1281                                 /* Remove an interface from state_list */
1282                                 llist_unlink(&state_list, iface_state);
1283                                 free(llist_pop(&iface_state));
1284                         }
1285
1286                         /* Actually write the new state */
1287                         state_fp = xfopen_for_write(CONFIG_IFUPDOWN_IFSTATE_PATH);
1288                         state = state_list;
1289                         while (state) {
1290                                 if (state->data) {
1291                                         fprintf(state_fp, "%s\n", state->data);
1292                                 }
1293                                 state = state->link;
1294                         }
1295                         fclose(state_fp);
1296                         llist_free(state_list, free);
1297                 }
1298         }
1299
1300         return any_failures;
1301 }