X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fresolve%2Fresolved-manager.c;h=f97989754d5594a087cf89e6595e7664ab341fd3;hp=988aa6e3b1a2fec802c848fddb84bef0345c9d9c;hb=c4147df156835513c43260a14fc9f7af177f737f;hpb=556a22945fcc88ca27ae7ecc46c9bb2727e37895 diff --git a/src/resolve/resolved-manager.c b/src/resolve/resolved-manager.c index 988aa6e3b..f97989754 100644 --- a/src/resolve/resolved-manager.c +++ b/src/resolve/resolved-manager.c @@ -426,30 +426,33 @@ static int manager_llmnr_start(Manager *m) { if (r < 0) return r; - r = manager_llmnr_ipv6_udp_fd(m); - if (r == -EADDRINUSE) - goto eaddrinuse; - if (r < 0) - return r; - r = manager_llmnr_ipv4_tcp_fd(m); if (r == -EADDRINUSE) goto eaddrinuse; if (r < 0) return r; - r = manager_llmnr_ipv6_tcp_fd(m); - if (r == -EADDRINUSE) - goto eaddrinuse; - if (r < 0) - return r; + if (socket_ipv6_is_supported()) { + r = manager_llmnr_ipv6_udp_fd(m); + if (r == -EADDRINUSE) + goto eaddrinuse; + if (r < 0) + return r; + + r = manager_llmnr_ipv6_tcp_fd(m); + if (r == -EADDRINUSE) + goto eaddrinuse; + if (r < 0) + return r; + } return 0; eaddrinuse: - log_warning("There appears to be another LLMNR respondering running. Turning off LLMNR support."); + log_warning("There appears to be another LLMNR responder running. Turning off LLMNR support."); m->llmnr_support = SUPPORT_NO; manager_llmnr_stop(m); + return 0; } @@ -536,10 +539,8 @@ Manager *manager_free(Manager *m) { dns_scope_free(m->unicast_scope); - while (m->dns_servers) - dns_server_free(m->dns_servers); - while (m->fallback_dns_servers) - dns_server_free(m->fallback_dns_servers); + manager_flush_dns_servers(m, DNS_SERVER_SYSTEM); + manager_flush_dns_servers(m, DNS_SERVER_FALLBACK); hashmap_free(m->links); hashmap_free(m->dns_transactions); @@ -676,7 +677,7 @@ clear: return r; } -static void write_resolve_conf_server(DnsServer *s, FILE *f, unsigned *count) { +static void write_resolv_conf_server(DnsServer *s, FILE *f, unsigned *count) { _cleanup_free_ char *t = NULL; int r; @@ -691,16 +692,39 @@ static void write_resolve_conf_server(DnsServer *s, FILE *f, unsigned *count) { } if (*count == MAXNS) - fputs("# Too many DNS servers configured, the following entries may be ignored\n", f); + fputs("# Too many DNS servers configured, the following entries may be ignored.\n", f); fprintf(f, "nameserver %s\n", t); (*count) ++; } +static void write_resolv_conf_search(const char *domain, FILE *f, + unsigned *count, unsigned *length) { + assert(domain); + assert(f); + assert(length); + + if (*count >= MAXDNSRCH || + *length + strlen(domain) > 256) { + if (*count == MAXDNSRCH) + fputs(" # Too many search domains configured, remaining ones ignored.", f); + if (*length <= 256) + fputs(" # Total length of all search domains is too long, remaining ones ignored.", f); + + return; + } + + fprintf(f, " %s", domain); + + (*length) += strlen(domain); + (*count) ++; +} + int manager_write_resolv_conf(Manager *m) { static const char path[] = "/run/systemd/resolve/resolv.conf"; _cleanup_free_ char *temp_path = NULL; _cleanup_fclose_ FILE *f = NULL; + _cleanup_set_free_ Set *dns = NULL, *domains = NULL; unsigned count = 0; DnsServer *s; Iterator i; @@ -712,6 +736,59 @@ int manager_write_resolv_conf(Manager *m) { /* Read the system /etc/resolv.conf first */ manager_read_resolv_conf(m); + /* Add the full list to a set, to filter out duplicates */ + dns = set_new(dns_server_hash_func, dns_server_compare_func); + if (!dns) + return -ENOMEM; + + domains = set_new(dns_name_hash_func, dns_name_compare_func); + if (!domains) + return -ENOMEM; + + /* First add the system-wide servers */ + LIST_FOREACH(servers, s, m->dns_servers) { + r = set_put(dns, s); + if (r == -EEXIST) + continue; + if (r < 0) + return r; + } + + /* Then, add the per-link servers and domains */ + HASHMAP_FOREACH(l, m->links, i) { + char **domain; + + LIST_FOREACH(servers, s, l->dns_servers) { + r = set_put(dns, s); + if (r == -EEXIST) + continue; + if (r < 0) + return r; + } + + if (!l->unicast_scope) + continue; + + STRV_FOREACH(domain, l->unicast_scope->domains) { + r = set_put(domains, *domain); + if (r == -EEXIST) + continue; + if (r < 0) + return r; + } + } + + /* If we found nothing, add the fallback servers */ + if (set_isempty(dns)) { + LIST_FOREACH(servers, s, m->fallback_dns_servers) { + r = set_put(dns, s); + if (r == -EEXIST) + continue; + if (r < 0) + return r; + } + } + r = fopen_temporary(path, &f, &temp_path); if (r < 0) return r; @@ -724,16 +801,23 @@ int manager_write_resolv_conf(Manager *m) { "# resolv.conf(5) in a different way, replace the symlink by a\n" "# static file or a different symlink.\n\n", f); - LIST_FOREACH(servers, s, m->dns_servers) - write_resolve_conf_server(s, f, &count); + if (set_isempty(dns)) + fputs("# No DNS servers known.\n", f); + else { + SET_FOREACH(s, dns, i) + write_resolv_conf_server(s, f, &count); + } + + if (!set_isempty(domains)) { + unsigned length = 0; + char *domain; - HASHMAP_FOREACH(l, m->links, i) - LIST_FOREACH(servers, s, l->dns_servers) - write_resolve_conf_server(s, f, &count); + count = 0; - if (count == 0) { - LIST_FOREACH(servers, s, m->fallback_dns_servers) - write_resolve_conf_server(s, f, &count); + fputs("search", f); + SET_FOREACH(domain, domains, i) + write_resolv_conf_search(domain, f, &count, &length); + fputs("\n", f); } r = fflush_and_check(f); @@ -757,7 +841,7 @@ int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret) { _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; union { struct cmsghdr header; /* For alignment */ - uint8_t buffer[CMSG_SPACE(MAX(sizeof(struct in_pktinfo), sizeof(struct in6_pktinfo))) + uint8_t buffer[CMSG_SPACE(MAXSIZE(struct in_pktinfo, struct in6_pktinfo)) + CMSG_SPACE(int) /* ttl/hoplimit */ + EXTRA_CMSG_SPACE /* kernel appears to require extra buffer space */]; } control; @@ -1740,6 +1824,18 @@ void manager_verify_all(Manager *m) { dns_zone_verify_all(&s->zone); } +void manager_flush_dns_servers(Manager *m, DnsServerType t) { + assert(m); + + if (t == DNS_SERVER_SYSTEM) + while (m->dns_servers) + dns_server_free(m->dns_servers); + + if (t == DNS_SERVER_FALLBACK) + while (m->fallback_dns_servers) + dns_server_free(m->fallback_dns_servers); +} + static const char* const support_table[_SUPPORT_MAX] = { [SUPPORT_NO] = "no", [SUPPORT_YES] = "yes",