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1 /*
2  * Copyright (C) 2008 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include <dirent.h>
18 #include <errno.h>
19 #include <fcntl.h>
20 #include <limits.h>
21 #include <poll.h>
22 #include <signal.h>
23 #include <stdarg.h>
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <sys/inotify.h>
28 #include <sys/stat.h>
29 #include <sys/time.h>
30 #include <sys/wait.h>
31 #include <sys/klog.h>
32 #include <time.h>
33 #include <unistd.h>
34 #include <sys/prctl.h>
35 
36 #include <cutils/debugger.h>
37 #include <cutils/properties.h>
38 #include <cutils/sockets.h>
39 #include <private/android_filesystem_config.h>
40 
41 #include <selinux/android.h>
42 
43 #include "dumpstate.h"
44 
45 static const int64_t NANOS_PER_SEC = 1000000000;
46 
47 /* list of native processes to include in the native dumps */
48 static const char* native_processes_to_dump[] = {
49         "/system/bin/drmserver",
50         "/system/bin/mediaserver",
51         "/system/bin/sdcard",
52         "/system/bin/surfaceflinger",
53         NULL,
54 };
55 
for_each_userid(void (* func)(int),const char * header)56 void for_each_userid(void (*func)(int), const char *header) {
57     DIR *d;
58     struct dirent *de;
59 
60     if (header) printf("\n------ %s ------\n", header);
61     func(0);
62 
63     if (!(d = opendir("/data/system/users"))) {
64         printf("Failed to open /data/system/users (%s)\n", strerror(errno));
65         return;
66     }
67 
68     while ((de = readdir(d))) {
69         int userid;
70         if (de->d_type != DT_DIR || !(userid = atoi(de->d_name))) {
71             continue;
72         }
73         func(userid);
74     }
75 
76     closedir(d);
77 }
78 
__for_each_pid(void (* helper)(int,const char *,void *),const char * header,void * arg)79 static void __for_each_pid(void (*helper)(int, const char *, void *), const char *header, void *arg) {
80     DIR *d;
81     struct dirent *de;
82 
83     if (!(d = opendir("/proc"))) {
84         printf("Failed to open /proc (%s)\n", strerror(errno));
85         return;
86     }
87 
88     printf("\n------ %s ------\n", header);
89     while ((de = readdir(d))) {
90         int pid;
91         int fd;
92         char cmdpath[255];
93         char cmdline[255];
94 
95         if (!(pid = atoi(de->d_name))) {
96             continue;
97         }
98 
99         sprintf(cmdpath,"/proc/%d/cmdline", pid);
100         memset(cmdline, 0, sizeof(cmdline));
101         if ((fd = open(cmdpath, O_RDONLY)) < 0) {
102             strcpy(cmdline, "N/A");
103         } else {
104             read(fd, cmdline, sizeof(cmdline) - 1);
105             close(fd);
106         }
107         helper(pid, cmdline, arg);
108     }
109 
110     closedir(d);
111 }
112 
for_each_pid_helper(int pid,const char * cmdline,void * arg)113 static void for_each_pid_helper(int pid, const char *cmdline, void *arg) {
114     for_each_pid_func *func = arg;
115     func(pid, cmdline);
116 }
117 
for_each_pid(for_each_pid_func func,const char * header)118 void for_each_pid(for_each_pid_func func, const char *header) {
119     __for_each_pid(for_each_pid_helper, header, func);
120 }
121 
for_each_tid_helper(int pid,const char * cmdline,void * arg)122 static void for_each_tid_helper(int pid, const char *cmdline, void *arg) {
123     DIR *d;
124     struct dirent *de;
125     char taskpath[255];
126     for_each_tid_func *func = arg;
127 
128     sprintf(taskpath, "/proc/%d/task", pid);
129 
130     if (!(d = opendir(taskpath))) {
131         printf("Failed to open %s (%s)\n", taskpath, strerror(errno));
132         return;
133     }
134 
135     func(pid, pid, cmdline);
136 
137     while ((de = readdir(d))) {
138         int tid;
139         int fd;
140         char commpath[255];
141         char comm[255];
142 
143         if (!(tid = atoi(de->d_name))) {
144             continue;
145         }
146 
147         if (tid == pid)
148             continue;
149 
150         sprintf(commpath,"/proc/%d/comm", tid);
151         memset(comm, 0, sizeof(comm));
152         if ((fd = open(commpath, O_RDONLY)) < 0) {
153             strcpy(comm, "N/A");
154         } else {
155             char *c;
156             read(fd, comm, sizeof(comm) - 1);
157             close(fd);
158 
159             c = strrchr(comm, '\n');
160             if (c) {
161                 *c = '\0';
162             }
163         }
164         func(pid, tid, comm);
165     }
166 
167     closedir(d);
168 }
169 
for_each_tid(for_each_tid_func func,const char * header)170 void for_each_tid(for_each_tid_func func, const char *header) {
171     __for_each_pid(for_each_tid_helper, header, func);
172 }
173 
show_wchan(int pid,int tid,const char * name)174 void show_wchan(int pid, int tid, const char *name) {
175     char path[255];
176     char buffer[255];
177     int fd;
178     char name_buffer[255];
179 
180     memset(buffer, 0, sizeof(buffer));
181 
182     sprintf(path, "/proc/%d/wchan", tid);
183     if ((fd = open(path, O_RDONLY)) < 0) {
184         printf("Failed to open '%s' (%s)\n", path, strerror(errno));
185         return;
186     }
187 
188     if (read(fd, buffer, sizeof(buffer)) < 0) {
189         printf("Failed to read '%s' (%s)\n", path, strerror(errno));
190         goto out_close;
191     }
192 
193     snprintf(name_buffer, sizeof(name_buffer), "%*s%s",
194              pid == tid ? 0 : 3, "", name);
195 
196     printf("%-7d %-32s %s\n", tid, name_buffer, buffer);
197 
198 out_close:
199     close(fd);
200     return;
201 }
202 
do_dump_settings(int userid)203 void do_dump_settings(int userid) {
204     char title[255];
205     char dbpath[255];
206     char sql[255];
207     sprintf(title, "SYSTEM SETTINGS (user %d)", userid);
208     if (userid == 0) {
209         strcpy(dbpath, "/data/data/com.android.providers.settings/databases/settings.db");
210         strcpy(sql, "pragma user_version; select * from system; select * from secure; select * from global;");
211     } else {
212         sprintf(dbpath, "/data/system/users/%d/settings.db", userid);
213         strcpy(sql, "pragma user_version; select * from system; select * from secure;");
214     }
215     run_command(title, 20, SU_PATH, "root", "sqlite3", dbpath, sql, NULL);
216     return;
217 }
218 
do_dmesg()219 void do_dmesg() {
220     printf("------ KERNEL LOG (dmesg) ------\n");
221     /* Get size of kernel buffer */
222     int size = klogctl(KLOG_SIZE_BUFFER, NULL, 0);
223     if (size <= 0) {
224         printf("Unexpected klogctl return value: %d\n\n", size);
225         return;
226     }
227     char *buf = (char *) malloc(size + 1);
228     if (buf == NULL) {
229         printf("memory allocation failed\n\n");
230         return;
231     }
232     int retval = klogctl(KLOG_READ_ALL, buf, size);
233     if (retval < 0) {
234         printf("klogctl failure\n\n");
235         free(buf);
236         return;
237     }
238     buf[retval] = '\0';
239     printf("%s\n\n", buf);
240     free(buf);
241     return;
242 }
243 
do_showmap(int pid,const char * name)244 void do_showmap(int pid, const char *name) {
245     char title[255];
246     char arg[255];
247 
248     sprintf(title, "SHOW MAP %d (%s)", pid, name);
249     sprintf(arg, "%d", pid);
250     run_command(title, 10, SU_PATH, "root", "showmap", arg, NULL);
251 }
252 
253 /* prints the contents of a file */
dump_file(const char * title,const char * path)254 int dump_file(const char *title, const char *path) {
255     int fd = open(path, O_RDONLY);
256     if (fd < 0) {
257         int err = errno;
258         if (title) printf("------ %s (%s) ------\n", title, path);
259         printf("*** %s: %s\n", path, strerror(err));
260         if (title) printf("\n");
261         return -1;
262     }
263     return dump_file_from_fd(title, path, fd);
264 }
265 
dump_file_from_fd(const char * title,const char * path,int fd)266 int dump_file_from_fd(const char *title, const char *path, int fd) {
267     char buffer[32768];
268 
269     if (title) printf("------ %s (%s", title, path);
270 
271     if (title) {
272         struct stat st;
273         if (memcmp(path, "/proc/", 6) && memcmp(path, "/sys/", 5) && !fstat(fd, &st)) {
274             char stamp[80];
275             time_t mtime = st.st_mtime;
276             strftime(stamp, sizeof(stamp), "%Y-%m-%d %H:%M:%S", localtime(&mtime));
277             printf(": %s", stamp);
278         }
279         printf(") ------\n");
280     }
281 
282     int newline = 0;
283     for (;;) {
284         int ret = read(fd, buffer, sizeof(buffer));
285         if (ret > 0) {
286             newline = (buffer[ret - 1] == '\n');
287             ret = fwrite(buffer, ret, 1, stdout);
288         }
289         if (ret <= 0) break;
290     }
291     close(fd);
292 
293     if (!newline) printf("\n");
294     if (title) printf("\n");
295     return 0;
296 }
297 
nanotime()298 static int64_t nanotime() {
299     struct timespec ts;
300     clock_gettime(CLOCK_MONOTONIC, &ts);
301     return (int64_t)ts.tv_sec * NANOS_PER_SEC + ts.tv_nsec;
302 }
303 
304 /* forks a command and waits for it to finish */
run_command(const char * title,int timeout_seconds,const char * command,...)305 int run_command(const char *title, int timeout_seconds, const char *command, ...) {
306     fflush(stdout);
307     int64_t start = nanotime();
308     pid_t pid = fork();
309 
310     /* handle error case */
311     if (pid < 0) {
312         printf("*** fork: %s\n", strerror(errno));
313         return pid;
314     }
315 
316     /* handle child case */
317     if (pid == 0) {
318         const char *args[1024] = {command};
319         size_t arg;
320 
321         /* make sure the child dies when dumpstate dies */
322         prctl(PR_SET_PDEATHSIG, SIGKILL);
323 
324         /* just ignore SIGPIPE, will go down with parent's */
325         struct sigaction sigact;
326         memset(&sigact, 0, sizeof(sigact));
327         sigact.sa_handler = SIG_IGN;
328         sigaction(SIGPIPE, &sigact, NULL);
329 
330         va_list ap;
331         va_start(ap, command);
332         if (title) printf("------ %s (%s", title, command);
333         for (arg = 1; arg < sizeof(args) / sizeof(args[0]); ++arg) {
334             args[arg] = va_arg(ap, const char *);
335             if (args[arg] == NULL) break;
336             if (title) printf(" %s", args[arg]);
337         }
338         if (title) printf(") ------\n");
339         fflush(stdout);
340 
341         execvp(command, (char**) args);
342         printf("*** exec(%s): %s\n", command, strerror(errno));
343         fflush(stdout);
344         _exit(-1);
345     }
346 
347     /* handle parent case */
348     for (;;) {
349         int status;
350         pid_t p = waitpid(pid, &status, WNOHANG);
351         int64_t elapsed = nanotime() - start;
352         if (p == pid) {
353             if (WIFSIGNALED(status)) {
354                 printf("*** %s: Killed by signal %d\n", command, WTERMSIG(status));
355             } else if (WIFEXITED(status) && WEXITSTATUS(status) > 0) {
356                 printf("*** %s: Exit code %d\n", command, WEXITSTATUS(status));
357             }
358             if (title) printf("[%s: %.3fs elapsed]\n\n", command, (float)elapsed / NANOS_PER_SEC);
359             return status;
360         }
361 
362         if (timeout_seconds && elapsed / NANOS_PER_SEC > timeout_seconds) {
363             printf("*** %s: Timed out after %.3fs (killing pid %d)\n", command, (float) elapsed / NANOS_PER_SEC, pid);
364             kill(pid, SIGTERM);
365             return -1;
366         }
367 
368         usleep(100000);  // poll every 0.1 sec
369     }
370 }
371 
372 size_t num_props = 0;
373 static char* props[2000];
374 
print_prop(const char * key,const char * name,void * user)375 static void print_prop(const char *key, const char *name, void *user) {
376     (void) user;
377     if (num_props < sizeof(props) / sizeof(props[0])) {
378         char buf[PROPERTY_KEY_MAX + PROPERTY_VALUE_MAX + 10];
379         snprintf(buf, sizeof(buf), "[%s]: [%s]\n", key, name);
380         props[num_props++] = strdup(buf);
381     }
382 }
383 
compare_prop(const void * a,const void * b)384 static int compare_prop(const void *a, const void *b) {
385     return strcmp(*(char * const *) a, *(char * const *) b);
386 }
387 
388 /* prints all the system properties */
print_properties()389 void print_properties() {
390     size_t i;
391     num_props = 0;
392     property_list(print_prop, NULL);
393     qsort(&props, num_props, sizeof(props[0]), compare_prop);
394 
395     printf("------ SYSTEM PROPERTIES ------\n");
396     for (i = 0; i < num_props; ++i) {
397         fputs(props[i], stdout);
398         free(props[i]);
399     }
400     printf("\n");
401 }
402 
403 /* redirect output to a service control socket */
redirect_to_socket(FILE * redirect,const char * service)404 void redirect_to_socket(FILE *redirect, const char *service) {
405     int s = android_get_control_socket(service);
406     if (s < 0) {
407         fprintf(stderr, "android_get_control_socket(%s): %s\n", service, strerror(errno));
408         exit(1);
409     }
410     if (listen(s, 4) < 0) {
411         fprintf(stderr, "listen(control socket): %s\n", strerror(errno));
412         exit(1);
413     }
414 
415     struct sockaddr addr;
416     socklen_t alen = sizeof(addr);
417     int fd = accept(s, &addr, &alen);
418     if (fd < 0) {
419         fprintf(stderr, "accept(control socket): %s\n", strerror(errno));
420         exit(1);
421     }
422 
423     fflush(redirect);
424     dup2(fd, fileno(redirect));
425     close(fd);
426 }
427 
428 /* redirect output to a file, optionally gzipping; returns gzip pid (or -1) */
redirect_to_file(FILE * redirect,char * path,int gzip_level)429 pid_t redirect_to_file(FILE *redirect, char *path, int gzip_level) {
430     char *chp = path;
431 
432     /* skip initial slash */
433     if (chp[0] == '/')
434         chp++;
435 
436     /* create leading directories, if necessary */
437     while (chp && chp[0]) {
438         chp = strchr(chp, '/');
439         if (chp) {
440             *chp = 0;
441             mkdir(path, 0770);  /* drwxrwx--- */
442             *chp++ = '/';
443         }
444     }
445 
446     int fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
447     if (fd < 0) {
448         fprintf(stderr, "%s: %s\n", path, strerror(errno));
449         exit(1);
450     }
451 
452     pid_t gzip_pid = -1;
453     if (gzip_level > 0) {
454         int fds[2];
455         if (pipe(fds)) {
456             fprintf(stderr, "pipe: %s\n", strerror(errno));
457             exit(1);
458         }
459 
460         fflush(redirect);
461         fflush(stdout);
462 
463         gzip_pid = fork();
464         if (gzip_pid < 0) {
465             fprintf(stderr, "fork: %s\n", strerror(errno));
466             exit(1);
467         }
468 
469         if (gzip_pid == 0) {
470             dup2(fds[0], STDIN_FILENO);
471             dup2(fd, STDOUT_FILENO);
472 
473             close(fd);
474             close(fds[0]);
475             close(fds[1]);
476 
477             char level[10];
478             snprintf(level, sizeof(level), "-%d", gzip_level);
479             execlp("gzip", "gzip", level, NULL);
480             fprintf(stderr, "exec(gzip): %s\n", strerror(errno));
481             _exit(-1);
482         }
483 
484         close(fd);
485         close(fds[0]);
486         fd = fds[1];
487     }
488 
489     dup2(fd, fileno(redirect));
490     close(fd);
491     return gzip_pid;
492 }
493 
should_dump_native_traces(const char * path)494 static bool should_dump_native_traces(const char* path) {
495     for (const char** p = native_processes_to_dump; *p; p++) {
496         if (!strcmp(*p, path)) {
497             return true;
498         }
499     }
500     return false;
501 }
502 
503 /* dump Dalvik and native stack traces, return the trace file location (NULL if none) */
dump_traces()504 const char *dump_traces() {
505     const char* result = NULL;
506 
507     char traces_path[PROPERTY_VALUE_MAX] = "";
508     property_get("dalvik.vm.stack-trace-file", traces_path, "");
509     if (!traces_path[0]) return NULL;
510 
511     /* move the old traces.txt (if any) out of the way temporarily */
512     char anr_traces_path[PATH_MAX];
513     strlcpy(anr_traces_path, traces_path, sizeof(anr_traces_path));
514     strlcat(anr_traces_path, ".anr", sizeof(anr_traces_path));
515     if (rename(traces_path, anr_traces_path) && errno != ENOENT) {
516         fprintf(stderr, "rename(%s, %s): %s\n", traces_path, anr_traces_path, strerror(errno));
517         return NULL;  // Can't rename old traces.txt -- no permission? -- leave it alone instead
518     }
519 
520     /* make the directory if necessary */
521     char anr_traces_dir[PATH_MAX];
522     strlcpy(anr_traces_dir, traces_path, sizeof(anr_traces_dir));
523     char *slash = strrchr(anr_traces_dir, '/');
524     if (slash != NULL) {
525         *slash = '\0';
526         if (!mkdir(anr_traces_dir, 0775)) {
527             chown(anr_traces_dir, AID_SYSTEM, AID_SYSTEM);
528             chmod(anr_traces_dir, 0775);
529             if (selinux_android_restorecon(anr_traces_dir, 0) == -1) {
530                 fprintf(stderr, "restorecon failed for %s: %s\n", anr_traces_dir, strerror(errno));
531             }
532         } else if (errno != EEXIST) {
533             fprintf(stderr, "mkdir(%s): %s\n", anr_traces_dir, strerror(errno));
534             return NULL;
535         }
536     }
537 
538     /* create a new, empty traces.txt file to receive stack dumps */
539     int fd = open(traces_path, O_CREAT | O_WRONLY | O_TRUNC | O_NOFOLLOW, 0666);  /* -rw-rw-rw- */
540     if (fd < 0) {
541         fprintf(stderr, "%s: %s\n", traces_path, strerror(errno));
542         return NULL;
543     }
544     int chmod_ret = fchmod(fd, 0666);
545     if (chmod_ret < 0) {
546         fprintf(stderr, "fchmod on %s failed: %s\n", traces_path, strerror(errno));
547         close(fd);
548         return NULL;
549     }
550 
551     /* walk /proc and kill -QUIT all Dalvik processes */
552     DIR *proc = opendir("/proc");
553     if (proc == NULL) {
554         fprintf(stderr, "/proc: %s\n", strerror(errno));
555         goto error_close_fd;
556     }
557 
558     /* use inotify to find when processes are done dumping */
559     int ifd = inotify_init();
560     if (ifd < 0) {
561         fprintf(stderr, "inotify_init: %s\n", strerror(errno));
562         goto error_close_fd;
563     }
564 
565     int wfd = inotify_add_watch(ifd, traces_path, IN_CLOSE_WRITE);
566     if (wfd < 0) {
567         fprintf(stderr, "inotify_add_watch(%s): %s\n", traces_path, strerror(errno));
568         goto error_close_ifd;
569     }
570 
571     struct dirent *d;
572     int dalvik_found = 0;
573     while ((d = readdir(proc))) {
574         int pid = atoi(d->d_name);
575         if (pid <= 0) continue;
576 
577         char path[PATH_MAX];
578         char data[PATH_MAX];
579         snprintf(path, sizeof(path), "/proc/%d/exe", pid);
580         ssize_t len = readlink(path, data, sizeof(data) - 1);
581         if (len <= 0) {
582             continue;
583         }
584         data[len] = '\0';
585 
586         if (!strncmp(data, "/system/bin/app_process", strlen("/system/bin/app_process"))) {
587             /* skip zygote -- it won't dump its stack anyway */
588             snprintf(path, sizeof(path), "/proc/%d/cmdline", pid);
589             int cfd = open(path, O_RDONLY);
590             len = read(cfd, data, sizeof(data) - 1);
591             close(cfd);
592             if (len <= 0) {
593                 continue;
594             }
595             data[len] = '\0';
596             if (!strncmp(data, "zygote", strlen("zygote"))) {
597                 continue;
598             }
599 
600             ++dalvik_found;
601             int64_t start = nanotime();
602             if (kill(pid, SIGQUIT)) {
603                 fprintf(stderr, "kill(%d, SIGQUIT): %s\n", pid, strerror(errno));
604                 continue;
605             }
606 
607             /* wait for the writable-close notification from inotify */
608             struct pollfd pfd = { ifd, POLLIN, 0 };
609             int ret = poll(&pfd, 1, 5000);  /* 5 sec timeout */
610             if (ret < 0) {
611                 fprintf(stderr, "poll: %s\n", strerror(errno));
612             } else if (ret == 0) {
613                 fprintf(stderr, "warning: timed out dumping pid %d\n", pid);
614             } else {
615                 struct inotify_event ie;
616                 read(ifd, &ie, sizeof(ie));
617             }
618 
619             if (lseek(fd, 0, SEEK_END) < 0) {
620                 fprintf(stderr, "lseek: %s\n", strerror(errno));
621             } else {
622                 dprintf(fd, "[dump dalvik stack %d: %.3fs elapsed]\n",
623                         pid, (float)(nanotime() - start) / NANOS_PER_SEC);
624             }
625         } else if (should_dump_native_traces(data)) {
626             /* dump native process if appropriate */
627             if (lseek(fd, 0, SEEK_END) < 0) {
628                 fprintf(stderr, "lseek: %s\n", strerror(errno));
629             } else {
630                 static uint16_t timeout_failures = 0;
631                 int64_t start = nanotime();
632 
633                 /* If 3 backtrace dumps fail in a row, consider debuggerd dead. */
634                 if (timeout_failures == 3) {
635                     dprintf(fd, "too many stack dump failures, skipping...\n");
636                 } else if (dump_backtrace_to_file_timeout(pid, fd, 20) == -1) {
637                     dprintf(fd, "dumping failed, likely due to a timeout\n");
638                     timeout_failures++;
639                 } else {
640                     timeout_failures = 0;
641                 }
642                 dprintf(fd, "[dump native stack %d: %.3fs elapsed]\n",
643                         pid, (float)(nanotime() - start) / NANOS_PER_SEC);
644             }
645         }
646     }
647 
648     if (dalvik_found == 0) {
649         fprintf(stderr, "Warning: no Dalvik processes found to dump stacks\n");
650     }
651 
652     static char dump_traces_path[PATH_MAX];
653     strlcpy(dump_traces_path, traces_path, sizeof(dump_traces_path));
654     strlcat(dump_traces_path, ".bugreport", sizeof(dump_traces_path));
655     if (rename(traces_path, dump_traces_path)) {
656         fprintf(stderr, "rename(%s, %s): %s\n", traces_path, dump_traces_path, strerror(errno));
657         goto error_close_ifd;
658     }
659     result = dump_traces_path;
660 
661     /* replace the saved [ANR] traces.txt file */
662     rename(anr_traces_path, traces_path);
663 
664 error_close_ifd:
665     close(ifd);
666 error_close_fd:
667     close(fd);
668     return result;
669 }
670 
dump_route_tables()671 void dump_route_tables() {
672     const char* const RT_TABLES_PATH = "/data/misc/net/rt_tables";
673     dump_file("RT_TABLES", RT_TABLES_PATH);
674     FILE* fp = fopen(RT_TABLES_PATH, "r");
675     if (!fp) {
676         printf("*** %s: %s\n", RT_TABLES_PATH, strerror(errno));
677         return;
678     }
679     char table[16];
680     // Each line has an integer (the table number), a space, and a string (the table name). We only
681     // need the table number. It's a 32-bit unsigned number, so max 10 chars. Skip the table name.
682     // Add a fixed max limit so this doesn't go awry.
683     for (int i = 0; i < 64 && fscanf(fp, " %10s %*s", table) == 1; ++i) {
684         run_command("ROUTE TABLE IPv4", 10, "ip", "-4", "route", "show", "table", table, NULL);
685         run_command("ROUTE TABLE IPv6", 10, "ip", "-6", "route", "show", "table", table, NULL);
686     }
687     fclose(fp);
688 }
689