1 | #include "lookup.h"
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2 | #include "stdio_impl.h"
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3 | #include <ctype.h>
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4 | #include <errno.h>
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5 | #include <string.h>
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6 | #include <netinet/in.h>
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7 |
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8 | int __get_resolv_conf(struct resolvconf *conf, char *search, size_t search_sz)
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9 | {
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10 | char line[256];
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11 | unsigned char _buf[256];
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12 | FILE *f, _f;
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13 | int nns = 0;
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14 |
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15 | conf->ndots = 1;
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16 | conf->timeout = 5;
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17 | conf->attempts = 2;
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18 | if (search) *search = 0;
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19 |
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20 | f = __fopen_rb_ca("/etc/resolv.conf", &_f, _buf, sizeof _buf);
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21 | if (!f) switch (errno) {
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22 | case ENOENT:
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23 | case ENOTDIR:
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24 | case EACCES:
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25 | goto no_resolv_conf;
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26 | default:
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27 | return -1;
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28 | }
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29 |
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30 | while (fgets(line, sizeof line, f)) {
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31 | char *p, *z;
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32 | if (!strchr(line, '\n') && !feof(f)) {
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33 | /* Ignore lines that get truncated rather than
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34 | * potentially misinterpreting them. */
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35 | int c;
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36 | do c = getc(f);
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37 | while (c != '\n' && c != EOF);
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38 | continue;
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39 | }
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40 | if (!strncmp(line, "options", 7) && isspace(line[7])) {
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41 | p = strstr(line, "ndots:");
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42 | if (p && isdigit(p[6])) {
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43 | p += 6;
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44 | unsigned long x = strtoul(p, &z, 10);
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45 | if (z != p) conf->ndots = x > 15 ? 15 : x;
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46 | }
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47 | p = strstr(line, "attempts:");
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48 | if (p && isdigit(p[9])) {
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49 | p += 9;
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50 | unsigned long x = strtoul(p, &z, 10);
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51 | if (z != p) conf->attempts = x > 10 ? 10 : x;
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52 | }
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53 | p = strstr(line, "timeout:");
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54 | if (p && (isdigit(p[8]) || p[8]=='.')) {
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55 | p += 8;
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56 | unsigned long x = strtoul(p, &z, 10);
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57 | if (z != p) conf->timeout = x > 60 ? 60 : x;
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58 | }
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59 | continue;
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60 | }
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61 | if (!strncmp(line, "nameserver", 10) && isspace(line[10])) {
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62 | if (nns >= MAXNS) continue;
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63 | for (p=line+11; isspace(*p); p++);
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64 | for (z=p; *z && !isspace(*z); z++);
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65 | *z=0;
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66 | if (__lookup_ipliteral(conf->ns+nns, p, AF_UNSPEC) > 0)
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67 | nns++;
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68 | continue;
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69 | }
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70 |
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71 | if (!search) continue;
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72 | if ((strncmp(line, "domain", 6) && strncmp(line, "search", 6))
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73 | || !isspace(line[6]))
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74 | continue;
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75 | for (p=line+7; isspace(*p); p++);
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76 | size_t l = strlen(p);
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77 | /* This can never happen anyway with chosen buffer sizes. */
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78 | if (l >= search_sz) continue;
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79 | memcpy(search, p, l+1);
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80 | }
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81 |
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82 | __fclose_ca(f);
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83 |
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84 | no_resolv_conf:
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85 | if (!nns) {
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86 | __lookup_ipliteral(conf->ns, "127.0.0.1", AF_UNSPEC);
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87 | nns = 1;
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88 | }
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89 |
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90 | conf->nns = nns;
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91 |
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92 | return 0;
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93 | }
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