diff options
| -rw-r--r-- | networking/nslookup.c | 104 |
1 files changed, 82 insertions, 22 deletions
diff --git a/networking/nslookup.c b/networking/nslookup.c index 3a614b0c6..e153eb585 100644 --- a/networking/nslookup.c +++ b/networking/nslookup.c @@ -318,6 +318,8 @@ struct globals { unsigned serv_count; struct ns *server; struct query *query; + char *search; + smalluint have_search_directive; } FIX_ALIASING; #define G (*(struct globals*)bb_common_bufsiz1) #define INIT_G() do { \ @@ -667,24 +669,60 @@ static void parse_resolvconf(void) resolv = fopen("/etc/resolv.conf", "r"); if (resolv) { - char line[128], *p; + char line[512]; /* "search" is defined to be up to 256 chars */ while (fgets(line, sizeof(line), resolv)) { - p = strtok(line, " \t\n"); + char *p, *arg; - if (!p || strcmp(p, "nameserver") != 0) + p = strtok(line, " \t\n"); + if (!p) + continue; + dbg("resolv_key:'%s'\n", p); + arg = strtok(NULL, "\n"); + dbg("resolv_arg:'%s'\n", arg); + if (!arg) continue; - p = strtok(NULL, " \t\n"); + if (strcmp(p, "domain") == 0) { + /* domain DOM */ + if (!G.have_search_directive) + goto set_search; + continue; + } + if (strcmp(p, "search") == 0) { + /* search DOM1 DOM2... */ + G.have_search_directive = 1; + set_search: + free(G.search); + G.search = xstrdup(arg); + dbg("search='%s'\n", G.search); + continue; + } - if (!p) + if (strcmp(p, "nameserver") != 0) continue; - add_ns(xstrdup(p)); + /* nameserver DNS */ + add_ns(xstrdup(arg)); } fclose(resolv); } + + if (!G.search) { + /* default search domain is domain part of hostname */ + char *h = safe_gethostname(); + char *d = strchr(h, '.'); + if (d) { + G.search = d + 1; + dbg("search='%s' (from hostname)\n", G.search); + } + /* else free(h); */ + } + + /* Cater for case of "domain ." in resolv.conf */ + if (G.search && LONE_CHAR(G.search, '.')) + G.search = NULL; } static void add_query(int type, const char *dname) @@ -695,7 +733,7 @@ static void add_query(int type, const char *dname) count = G.query_count++; - G.query = xrealloc_vector(G.query, /*2=2^1:*/ 1, count); + G.query = xrealloc_vector(G.query, /*4=2^2:*/ 2, count); new_q = &G.query[count]; dbg("new query#%u type %u for '%s'\n", count, type, dname); @@ -709,6 +747,28 @@ static void add_query(int type, const char *dname) new_q->qlen = qlen; } +static void add_query_with_search(int type, const char *dname) +{ + char *s; + + if (type == T_PTR || !G.search || strchr(dname, '.')) { + add_query(type, dname); + return; + } + + s = G.search; + for (;;) { + char *fullname, *e; + + e = skip_non_whitespace(s); + fullname = xasprintf("%s.%.*s", dname, (int)(e - s), s); + add_query(type, fullname); + s = skip_whitespace(e); + if (!*s) + break; + } +} + static char *make_ptr(const char *addrstr) { unsigned char addr[16]; @@ -833,6 +893,18 @@ int nslookup_main(int argc UNUSED_PARAM, char **argv) } } + /* Use given DNS server if present */ + if (argv[1]) { + if (argv[2]) + bb_show_usage(); + add_ns(argv[1]); + } else { + parse_resolvconf(); + /* Fall back to localhost if we could not find NS in resolv.conf */ + if (G.serv_count == 0) + add_ns("127.0.0.1"); + } + if (types == 0) { /* No explicit type given, guess query type. * If we can convert the domain argument into a ptr (means that @@ -846,31 +918,19 @@ int nslookup_main(int argc UNUSED_PARAM, char **argv) if (ptr) { add_query(T_PTR, ptr); } else { - add_query(T_A, argv[0]); + add_query_with_search(T_A, argv[0]); #if ENABLE_FEATURE_IPV6 - add_query(T_AAAA, argv[0]); + add_query_with_search(T_AAAA, argv[0]); #endif } } else { int c; for (c = 0; c < ARRAY_SIZE(qtypes); c++) { if (types & (1 << c)) - add_query(qtypes[c].type, argv[0]); + add_query_with_search(qtypes[c].type, argv[0]); } } - /* Use given DNS server if present */ - if (argv[1]) { - if (argv[2]) - bb_show_usage(); - add_ns(argv[1]); - } else { - parse_resolvconf(); - /* Fall back to localhost if we could not find NS in resolv.conf */ - if (G.serv_count == 0) - add_ns("127.0.0.1"); - } - for (rc = 0; rc < G.serv_count;) { int c; |