X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fresolve%2Fresolved-manager.c;h=2edfb9f7fdee20b50f071e94d9bc19d85e7f53cb;hp=523ed20208683b0ed32e76da9d1209c6810259c0;hb=36a03ca2a8952ca1acb29fbe796210c27ff71aff;hpb=bf3f1271e2cc0c22b11c8a805a997578dabe9191 diff --git a/src/resolve/resolved-manager.c b/src/resolve/resolved-manager.c index 523ed2020..2edfb9f7f 100644 --- a/src/resolve/resolved-manager.c +++ b/src/resolve/resolved-manager.c @@ -32,7 +32,14 @@ #include "network-internal.h" #include "conf-parser.h" #include "socket-util.h" -#include "resolved.h" +#include "af-list.h" +#include "utf8.h" +#include "fileio-label.h" + +#include "resolved-dns-domain.h" +#include "resolved-conf.h" +#include "resolved-bus.h" +#include "resolved-manager.h" #define SEND_TIMEOUT_USEC (200 * USEC_PER_MSEC) @@ -58,10 +65,10 @@ static int manager_process_link(sd_rtnl *rtnl, sd_rtnl_message *mm, void *userda switch (type) { - case RTM_NEWLINK: - if (!l) { - log_debug("Found link %i", ifindex); + case RTM_NEWLINK:{ + bool is_new = !l; + if (!l) { r = link_new(m, &l, ifindex); if (r < 0) goto fail; @@ -71,11 +78,19 @@ static int manager_process_link(sd_rtnl *rtnl, sd_rtnl_message *mm, void *userda if (r < 0) goto fail; + r = link_update_monitor(l); + if (r < 0) + goto fail; + + if (is_new) + log_debug("Found new link %i/%s", ifindex, l->name); + break; + } case RTM_DELLINK: if (l) { - log_debug("Removing link %i", l->ifindex); + log_debug("Removing link %i/%s", l->ifindex, l->name); link_free(l); } @@ -85,7 +100,7 @@ static int manager_process_link(sd_rtnl *rtnl, sd_rtnl_message *mm, void *userda return 0; fail: - log_warning("Failed to process RTNL link message: %s", strerror(-r)); + log_warning_errno(r, "Failed to process RTNL link message: %m"); return 0; } @@ -170,11 +185,10 @@ static int manager_process_address(sd_rtnl *rtnl, sd_rtnl_message *mm, void *use return 0; fail: - log_warning("Failed to process RTNL address message: %s", strerror(-r)); + log_warning_errno(r, "Failed to process RTNL address message: %m"); return 0; } - static int manager_rtnl_listen(Manager *m) { _cleanup_rtnl_message_unref_ sd_rtnl_message *req = NULL, *reply = NULL; sd_rtnl_message *i; @@ -264,12 +278,12 @@ static int on_network_event(sd_event_source *s, int fd, uint32_t revents, void * HASHMAP_FOREACH(l, m->links, i) { r = link_update_monitor(l); if (r < 0) - log_warning("Failed to update monitor information for %i: %s", l->ifindex, strerror(-r)); + log_warning_errno(r, "Failed to update monitor information for %i: %m", l->ifindex); } r = manager_write_resolv_conf(m); if (r < 0) - log_warning("Could not update resolv.conf: %s", strerror(-r)); + log_warning_errno(r, "Could not update resolv.conf: %m"); return 0; } @@ -298,84 +312,147 @@ static int manager_network_monitor_listen(Manager *m) { return 0; } -static int parse_dns_server_string(Manager *m, const char *string) { - char *word, *state; - size_t length; +static int determine_hostname(char **ret) { + _cleanup_free_ char *h = NULL, *n = NULL; int r; - assert(m); - assert(string); - - FOREACH_WORD_QUOTED(word, length, string, state) { - char buffer[length+1]; - int family; - union in_addr_union addr; - - memcpy(buffer, word, length); - buffer[length] = 0; + assert(ret); - r = in_addr_from_string_auto(buffer, &family, &addr); - if (r < 0) { - log_warning("Ignoring invalid DNS address '%s'", buffer); - continue; - } + h = gethostname_malloc(); + if (!h) + return log_oom(); - /* filter out duplicates */ - if (manager_find_dns_server(m, family, &addr)) - continue; + if (!utf8_is_valid(h)) { + log_error("System hostname is not UTF-8 clean."); + return -EINVAL; + } - r = dns_server_new(m, NULL, NULL, family, &addr); - if (r < 0) - return r; + r = dns_name_normalize(h, &n); + if (r < 0) { + log_error("System hostname '%s' cannot be normalized.", h); + return r; } + *ret = n; + n = NULL; + return 0; } -int config_parse_dnsv( - const char *unit, - const char *filename, - unsigned line, - const char *section, - unsigned section_line, - const char *lvalue, - int ltype, - const char *rvalue, - void *data, - void *userdata) { - +static int on_hostname_change(sd_event_source *es, int fd, uint32_t revents, void *userdata) { + _cleanup_free_ char *h = NULL; Manager *m = userdata; int r; - assert(filename); - assert(lvalue); - assert(rvalue); assert(m); - /* Empty assignment means clear the list */ - if (isempty(rvalue)) { - while (m->dns_servers) - dns_server_free(m->dns_servers); + r = determine_hostname(&h); + if (r < 0) + return 0; /* ignore invalid hostnames */ + if (streq(h, m->hostname)) + return 0; + + log_info("System hostname changed to '%s'.", h); + free(m->hostname); + m->hostname = h; + h = NULL; + + manager_refresh_rrs(m); + + return 0; +} + +static int manager_watch_hostname(Manager *m) { + int r; + + assert(m); + + m->hostname_fd = open("/proc/sys/kernel/hostname", O_RDONLY|O_CLOEXEC|O_NDELAY|O_NOCTTY); + if (m->hostname_fd < 0) { + log_warning_errno(errno, "Failed to watch hostname: %m"); return 0; } - r = parse_dns_server_string(m, rvalue); + r = sd_event_add_io(m->event, &m->hostname_event_source, m->hostname_fd, 0, on_hostname_change, m); if (r < 0) { - log_error("Failed to parse DNS server string"); - return r; + if (r == -EPERM) + /* kernels prior to 3.2 don't support polling this file. Ignore the failure. */ + m->hostname_fd = safe_close(m->hostname_fd); + else + return log_error_errno(r, "Failed to add hostname event source: %m"); } + r = determine_hostname(&m->hostname); + if (r < 0) { + log_info("Defaulting to hostname 'linux'."); + m->hostname = strdup("linux"); + if (!m->hostname) + return log_oom(); + } else + log_info("Using system hostname '%s'.", m->hostname); + return 0; } -int manager_parse_config_file(Manager *m) { +static void manager_llmnr_stop(Manager *m) { assert(m); - return config_parse(NULL, "/etc/systemd/resolved.conf", NULL, - "Resolve\0", - config_item_perf_lookup, resolved_gperf_lookup, - false, false, true, m); + m->llmnr_ipv4_udp_event_source = sd_event_source_unref(m->llmnr_ipv4_udp_event_source); + m->llmnr_ipv4_udp_fd = safe_close(m->llmnr_ipv4_udp_fd); + + m->llmnr_ipv6_udp_event_source = sd_event_source_unref(m->llmnr_ipv6_udp_event_source); + m->llmnr_ipv6_udp_fd = safe_close(m->llmnr_ipv6_udp_fd); + + m->llmnr_ipv4_tcp_event_source = sd_event_source_unref(m->llmnr_ipv4_tcp_event_source); + m->llmnr_ipv4_tcp_fd = safe_close(m->llmnr_ipv4_tcp_fd); + + m->llmnr_ipv6_tcp_event_source = sd_event_source_unref(m->llmnr_ipv6_tcp_event_source); + m->llmnr_ipv6_tcp_fd = safe_close(m->llmnr_ipv6_tcp_fd); +} + +static int manager_llmnr_start(Manager *m) { + int r; + + assert(m); + + if (m->llmnr_support == SUPPORT_NO) + return 0; + + r = manager_llmnr_ipv4_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; + + 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 responder running. Turning off LLMNR support."); + m->llmnr_support = SUPPORT_NO; + manager_llmnr_stop(m); + + return 0; } int manager_new(Manager **ret) { @@ -391,17 +468,15 @@ int manager_new(Manager **ret) { m->dns_ipv4_fd = m->dns_ipv6_fd = -1; m->llmnr_ipv4_udp_fd = m->llmnr_ipv6_udp_fd = -1; m->llmnr_ipv4_tcp_fd = m->llmnr_ipv6_tcp_fd = -1; + m->hostname_fd = -1; - m->use_llmnr = true; + m->llmnr_support = SUPPORT_YES; + m->read_resolv_conf = true; - r = parse_dns_server_string(m, DNS_SERVERS); + r = manager_parse_dns_server(m, DNS_SERVER_FALLBACK, DNS_SERVERS); if (r < 0) return r; - m->hostname = gethostname_malloc(); - if (!m->hostname) - return -ENOMEM; - r = sd_event_default(&m->event); if (r < 0) return r; @@ -411,6 +486,10 @@ int manager_new(Manager **ret) { sd_event_set_watchdog(m->event, true); + r = manager_watch_hostname(m); + if (r < 0) + return r; + r = dns_scope_new(m, &m->unicast_scope, NULL, DNS_PROTOCOL_DNS, AF_UNSPEC); if (r < 0) return r; @@ -427,44 +506,43 @@ int manager_new(Manager **ret) { if (r < 0) return r; - r = manager_llmnr_ipv4_udp_fd(m); - if (r < 0) - return r; - r = manager_llmnr_ipv6_udp_fd(m); - if (r < 0) - return r; - r = manager_llmnr_ipv4_tcp_fd(m); - if (r < 0) - return r; - r = manager_llmnr_ipv6_tcp_fd(m); - if (r < 0) - return r; - *ret = m; m = NULL; return 0; } +int manager_start(Manager *m) { + int r; + + assert(m); + + r = manager_llmnr_start(m); + if (r < 0) + return r; + + return 0; +} + Manager *manager_free(Manager *m) { Link *l; if (!m) return NULL; - while (m->dns_queries) - dns_query_free(m->dns_queries); - - hashmap_free(m->dns_query_transactions); - while ((l = hashmap_first(m->links))) link_free(l); - hashmap_free(m->links); + + while (m->dns_queries) + dns_query_free(m->dns_queries); dns_scope_free(m->unicast_scope); - while (m->dns_servers) - dns_server_free(m->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); sd_event_source_unref(m->network_event_source); sd_network_monitor_unref(m->network_monitor); @@ -474,16 +552,9 @@ Manager *manager_free(Manager *m) { safe_close(m->dns_ipv4_fd); safe_close(m->dns_ipv6_fd); - sd_event_source_unref(m->llmnr_ipv4_udp_event_source); - sd_event_source_unref(m->llmnr_ipv6_udp_event_source); - safe_close(m->llmnr_ipv4_udp_fd); - safe_close(m->llmnr_ipv6_udp_fd); - - sd_event_source_unref(m->llmnr_ipv4_tcp_event_source); - sd_event_source_unref(m->llmnr_ipv6_tcp_event_source); - safe_close(m->llmnr_ipv4_tcp_fd); - safe_close(m->llmnr_ipv6_tcp_fd); + manager_llmnr_stop(m); + sd_bus_slot_unref(m->prepare_for_sleep_slot); sd_event_source_unref(m->bus_retry_event_source); sd_bus_unref(m->bus); @@ -491,13 +562,131 @@ Manager *manager_free(Manager *m) { dns_resource_key_unref(m->host_ipv4_key); dns_resource_key_unref(m->host_ipv6_key); + + safe_close(m->hostname_fd); + sd_event_source_unref(m->hostname_event_source); free(m->hostname); + free(m); return NULL; } -static void write_resolve_conf_server(DnsServer *s, FILE *f, unsigned *count) { +int manager_read_resolv_conf(Manager *m) { + _cleanup_fclose_ FILE *f = NULL; + struct stat st, own; + char line[LINE_MAX]; + DnsServer *s, *nx; + usec_t t; + int r; + + assert(m); + + /* Reads the system /etc/resolv.conf, if it exists and is not + * symlinked to our own resolv.conf instance */ + + if (!m->read_resolv_conf) + return 0; + + r = stat("/etc/resolv.conf", &st); + if (r < 0) { + if (errno != ENOENT) + log_warning_errno(errno, "Failed to open /etc/resolv.conf: %m"); + r = -errno; + goto clear; + } + + /* Have we already seen the file? */ + t = timespec_load(&st.st_mtim); + if (t == m->resolv_conf_mtime) + return 0; + + m->resolv_conf_mtime = t; + + /* Is it symlinked to our own file? */ + if (stat("/run/systemd/resolve/resolv.conf", &own) >= 0 && + st.st_dev == own.st_dev && + st.st_ino == own.st_ino) { + r = 0; + goto clear; + } + + f = fopen("/etc/resolv.conf", "re"); + if (!f) { + if (errno != ENOENT) + log_warning_errno(errno, "Failed to open /etc/resolv.conf: %m"); + r = -errno; + goto clear; + } + + if (fstat(fileno(f), &st) < 0) { + log_error_errno(errno, "Failed to stat open file: %m"); + r = -errno; + goto clear; + } + + LIST_FOREACH(servers, s, m->dns_servers) + s->marked = true; + + FOREACH_LINE(line, f, r = -errno; goto clear) { + union in_addr_union address; + int family; + char *l; + const char *a; + + truncate_nl(line); + + l = strstrip(line); + if (*l == '#' || *l == ';') + continue; + + a = first_word(l, "nameserver"); + if (!a) + continue; + + r = in_addr_from_string_auto(a, &family, &address); + if (r < 0) { + log_warning("Failed to parse name server %s.", a); + continue; + } + + LIST_FOREACH(servers, s, m->dns_servers) + if (s->family == family && in_addr_equal(family, &s->address, &address) > 0) + break; + + if (s) + s->marked = false; + else { + r = dns_server_new(m, NULL, DNS_SERVER_SYSTEM, NULL, family, &address); + if (r < 0) + goto clear; + } + } + + LIST_FOREACH_SAFE(servers, s, nx, m->dns_servers) + if (s->marked) + dns_server_free(s); + + /* Whenever /etc/resolv.conf changes, start using the first + * DNS server of it. This is useful to deal with broken + * network managing implementations (like NetworkManager), + * that when connecting to a VPN place both the VPN DNS + * servers and the local ones in /etc/resolv.conf. Without + * resetting the DNS server to use back to the first entry we + * will continue to use the local one thus being unable to + * resolve VPN domains. */ + manager_set_dns_server(m, m->dns_servers); + + return 0; + +clear: + while (m->dns_servers) + dns_server_free(m->dns_servers); + + return r; +} + +static void write_resolv_conf_server(DnsServer *s, FILE *f, unsigned *count) { _cleanup_free_ char *t = NULL; int r; @@ -506,23 +695,78 @@ static void write_resolve_conf_server(DnsServer *s, FILE *f, unsigned *count) { assert(count); r = in_addr_to_string(s->family, &s->address, &t); - if (r < 0) { - log_warning("Invalid DNS address. Ignoring."); + if (r < 0) { + log_warning_errno(r, "Invalid DNS address. Ignoring: %m"); return; } 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) ++; +} + +static int write_resolv_conf_contents(FILE *f, Set *dns, Set *domains) { + Iterator i; + + fputs("# This file is managed by systemd-resolved(8). Do not edit.\n#\n" + "# Third party programs must not access this file directly, but\n" + "# only through the symlink at /etc/resolv.conf. To manage\n" + "# resolv.conf(5) in a different way, replace the symlink by a\n" + "# static file or a different symlink.\n\n", f); + + if (set_isempty(dns)) + fputs("# No DNS servers known.\n", f); + else { + DnsServer *s; + unsigned count = 0; + + SET_FOREACH(s, dns, i) + write_resolv_conf_server(s, f, &count); + } + + if (!set_isempty(domains)) { + unsigned length = 0, count = 0; + char *domain; + + fputs("search", f); + SET_FOREACH(domain, domains, i) + write_resolv_conf_search(domain, f, &count, &length); + fputs("\n", f); + } + + return fflush_and_check(f); +} + + int manager_write_resolv_conf(Manager *m) { - const char *path = "/run/systemd/resolve/resolv.conf"; + static const char path[] = "/run/systemd/resolve/resolv.conf"; _cleanup_free_ char *temp_path = NULL; _cleanup_fclose_ FILE *f = NULL; - unsigned count = 0; + _cleanup_set_free_ Set *dns = NULL, *domains = NULL; DnsServer *s; Iterator i; Link *l; @@ -530,26 +774,69 @@ int manager_write_resolv_conf(Manager *m) { assert(m); - r = fopen_temporary(path, &f, &temp_path); - if (r < 0) - return r; + /* Read the system /etc/resolv.conf first */ + manager_read_resolv_conf(m); - fchmod(fileno(f), 0644); + /* Add the full list to a set, to filter out duplicates */ + dns = set_new(&dns_server_hash_ops); + if (!dns) + return -ENOMEM; - fputs("# This file is managed by systemd-resolved(8). Do not edit.\n#\n" - "# Third party programs must not access this file directly, but\n" - "# only through the symlink at /etc/resolv.conf. To manage\n" - "# resolv.conf(5) in a different way, replace the symlink by a\n" - "# static file or a different symlink.\n\n", f); + domains = set_new(&dns_name_hash_ops); + if (!domains) + return -ENOMEM; - HASHMAP_FOREACH(l, m->links, i) - LIST_FOREACH(servers, s, l->dns_servers) - write_resolve_conf_server(s, f, &count); + /* 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; + } - LIST_FOREACH(servers, s, m->dns_servers) - write_resolve_conf_server(s, f, &count); + /* 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; + } - r = fflush_and_check(f); + 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_label(path, path, &f, &temp_path); + if (r < 0) + return r; + + fchmod(fileno(f), 0644); + + r = write_resolv_conf_contents(f, dns, domains); if (r < 0) goto fail; @@ -570,7 +857,7 @@ 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; @@ -681,7 +968,7 @@ int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret) { * device if the packet came from the local host since it * avoids the routing table in such a case. Let's unset the * interface index in such a case. */ - if (p->ifindex > 0 && manager_ifindex_is_loopback(m, p->ifindex) != 0) + if (p->ifindex == LOOPBACK_IFINDEX) p->ifindex = 0; /* If we don't know the interface index still, we look for the @@ -697,7 +984,7 @@ int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret) { static int on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) { _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; - DnsQueryTransaction *t = NULL; + DnsTransaction *t = NULL; Manager *m = userdata; int r; @@ -706,11 +993,11 @@ static int on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *use return r; if (dns_packet_validate_reply(p) > 0) { - t = hashmap_get(m->dns_query_transactions, UINT_TO_PTR(DNS_PACKET_ID(p))); + t = hashmap_get(m->dns_transactions, UINT_TO_PTR(DNS_PACKET_ID(p))); if (!t) return 0; - dns_query_transaction_process_reply(t, p); + dns_transaction_process_reply(t, p); } else log_debug("Invalid DNS packet."); @@ -908,6 +1195,8 @@ int manager_send(Manager *m, int fd, int ifindex, int family, const union in_add assert(port > 0); assert(p); + log_debug("Sending %s packet with id %u on interface %i/%s", DNS_PACKET_QR(p) ? "response" : "query", DNS_PACKET_ID(p), ifindex, af_to_name(family)); + if (family == AF_INET) return manager_ipv4_send(m, fd, ifindex, &addr->in, port, p); else if (family == AF_INET6) @@ -916,28 +1205,71 @@ int manager_send(Manager *m, int fd, int ifindex, int family, const union in_add return -EAFNOSUPPORT; } - DnsServer* manager_find_dns_server(Manager *m, int family, const union in_addr_union *in_addr) { DnsServer *s; assert(m); assert(in_addr); - LIST_FOREACH(servers, s, m->dns_servers) { + LIST_FOREACH(servers, s, m->dns_servers) + if (s->family == family && in_addr_equal(family, &s->address, in_addr) > 0) + return s; - if (s->family == family && - in_addr_equal(family, &s->address, in_addr)) + LIST_FOREACH(servers, s, m->fallback_dns_servers) + if (s->family == family && in_addr_equal(family, &s->address, in_addr) > 0) return s; - } return NULL; } +DnsServer *manager_set_dns_server(Manager *m, DnsServer *s) { + assert(m); + + if (m->current_dns_server == s) + return s; + + if (s) { + _cleanup_free_ char *ip = NULL; + + in_addr_to_string(s->family, &s->address, &ip); + log_info("Switching to system DNS server %s.", strna(ip)); + } + + m->current_dns_server = s; + + if (m->unicast_scope) + dns_cache_flush(&m->unicast_scope->cache); + + return s; +} + DnsServer *manager_get_dns_server(Manager *m) { + Link *l; assert(m); + /* Try to read updates resolv.conf */ + manager_read_resolv_conf(m); + if (!m->current_dns_server) - m->current_dns_server = m->dns_servers; + manager_set_dns_server(m, m->dns_servers); + + if (!m->current_dns_server) { + bool found = false; + Iterator i; + + /* No DNS servers configured, let's see if there are + * any on any links. If not, we use the fallback + * servers */ + + HASHMAP_FOREACH(l, m->links, i) + if (l->dns_servers) { + found = true; + break; + } + + if (!found) + manager_set_dns_server(m, m->fallback_dns_servers); + } return m->current_dns_server; } @@ -945,20 +1277,23 @@ DnsServer *manager_get_dns_server(Manager *m) { void manager_next_dns_server(Manager *m) { assert(m); - if (!m->current_dns_server) { - m->current_dns_server = m->dns_servers; - return; - } - + /* If there's currently no DNS server set, then the next + * manager_get_dns_server() will find one */ if (!m->current_dns_server) return; + /* Change to the next one */ if (m->current_dns_server->servers_next) { - m->current_dns_server = m->current_dns_server->servers_next; + manager_set_dns_server(m, m->current_dns_server->servers_next); return; } - m->current_dns_server = m->dns_servers; + /* If there was no next one, then start from the beginning of + * the list */ + if (m->current_dns_server->type == DNS_SERVER_FALLBACK) + manager_set_dns_server(m, m->fallback_dns_servers); + else + manager_set_dns_server(m, m->dns_servers); } uint32_t manager_find_mtu(Manager *m) { @@ -983,38 +1318,36 @@ uint32_t manager_find_mtu(Manager *m) { static int on_llmnr_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) { _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; - DnsQueryTransaction *t = NULL; + DnsTransaction *t = NULL; Manager *m = userdata; + DnsScope *scope; int r; r = manager_recv(m, fd, DNS_PROTOCOL_LLMNR, &p); if (r <= 0) return r; - if (dns_packet_validate_reply(p) > 0) { - t = hashmap_get(m->dns_query_transactions, UINT_TO_PTR(DNS_PACKET_ID(p))); - if (!t) - return 0; + scope = manager_find_scope(m, p); + if (!scope) { + log_warning("Got LLMNR UDP packet on unknown scope. Ignoring."); + return 0; + } - dns_query_transaction_process_reply(t, p); + if (dns_packet_validate_reply(p) > 0) { + log_debug("Got reply packet for id %u", DNS_PACKET_ID(p)); - } else if (dns_packet_validate_query(p) > 0) { - Link *l; + dns_scope_check_conflicts(scope, p); - l = hashmap_get(m->links, INT_TO_PTR(p->ifindex)); - if (l) { - DnsScope *scope = NULL; + t = hashmap_get(m->dns_transactions, UINT_TO_PTR(DNS_PACKET_ID(p))); + if (t) + dns_transaction_process_reply(t, p); - if (p->family == AF_INET) - scope = l->llmnr_ipv4_scope; - else if (p->family == AF_INET6) - scope = l->llmnr_ipv6_scope; + } else if (dns_packet_validate_query(p) > 0) { + log_debug("Got query packet for id %u", DNS_PACKET_ID(p)); - if (scope) - dns_scope_process_query(scope, NULL, p); - } + dns_scope_process_query(scope, NULL, p); } else - log_debug("Invalid LLMNR packet."); + log_debug("Invalid LLMNR UDP packet."); return 0; } @@ -1177,29 +1510,26 @@ fail: } static int on_llmnr_stream_packet(DnsStream *s) { - assert(s); + DnsScope *scope; - if (dns_packet_validate_query(s->read_packet) > 0) { - Link *l; + assert(s); - l = hashmap_get(s->manager->links, INT_TO_PTR(s->read_packet->ifindex)); - if (l) { - DnsScope *scope = NULL; + scope = manager_find_scope(s->manager, s->read_packet); + if (!scope) { + log_warning("Got LLMNR TCP packet on unknown scope. Ignroing."); + return 0; + } - if (s->read_packet->family == AF_INET) - scope = l->llmnr_ipv4_scope; - else if (s->read_packet->family == AF_INET6) - scope = l->llmnr_ipv6_scope; + if (dns_packet_validate_query(s->read_packet) > 0) { + log_debug("Got query packet for id %u", DNS_PACKET_ID(s->read_packet)); - if (scope) { - dns_scope_process_query(scope, s, s->read_packet); + dns_scope_process_query(scope, s, s->read_packet); - /* If no reply packet was set, we free the stream */ - if (s->write_packet) - return 0; - } - } - } + /* If no reply packet was set, we free the stream */ + if (s->write_packet) + return 0; + } else + log_debug("Invalid LLMNR TCP packet."); dns_stream_free(s); return 0; @@ -1373,29 +1703,144 @@ fail: return r; } -int manager_ifindex_is_loopback(Manager *m, int ifindex) { +int manager_find_ifindex(Manager *m, int family, const union in_addr_union *in_addr) { + LinkAddress *a; + + assert(m); + + a = manager_find_link_address(m, family, in_addr); + if (a) + return a->link->ifindex; + + return 0; +} + +void manager_refresh_rrs(Manager *m) { + Iterator i; Link *l; + assert(m); - if (ifindex <= 0) - return -EINVAL; + m->host_ipv4_key = dns_resource_key_unref(m->host_ipv4_key); + m->host_ipv6_key = dns_resource_key_unref(m->host_ipv6_key); - l = hashmap_get(m->links, INT_TO_PTR(ifindex)); - if (l->flags & IFF_LOOPBACK) - return 1; + HASHMAP_FOREACH(l, m->links, i) { + link_add_rrs(l, true); + link_add_rrs(l, false); + } +} + +int manager_next_hostname(Manager *m) { + const char *p; + uint64_t u, a; + char *h; + + assert(m); + + p = strchr(m->hostname, 0); + assert(p); + + while (p > m->hostname) { + if (!strchr("0123456789", p[-1])) + break; + + p--; + } + + if (*p == 0 || safe_atou64(p, &u) < 0 || u <= 0) + u = 1; + + /* Add a random number to the old value. This way we can avoid + * that two hosts pick the same hostname, win on IPv4 and lose + * on IPv6 (or vice versa), and pick the same hostname + * replacement hostname, ad infinitum. We still want the + * numbers to go up monotonically, hence we just add a random + * value 1..10 */ + + random_bytes(&a, sizeof(a)); + u += 1 + a % 10; + + if (asprintf(&h, "%.*s%" PRIu64, (int) (p - m->hostname), m->hostname, u) < 0) + return -ENOMEM; + + log_info("Hostname conflict, changing published hostname from '%s' to '%s'.", m->hostname, h); + + free(m->hostname); + m->hostname = h; + + manager_refresh_rrs(m); return 0; } -int manager_find_ifindex(Manager *m, int family, const union in_addr_union *in_addr) { - Link *l; +LinkAddress* manager_find_link_address(Manager *m, int family, const union in_addr_union *in_addr) { Iterator i; + Link *l; assert(m); - HASHMAP_FOREACH(l, m->links, i) - if (link_find_address(l, family, in_addr)) - return l->ifindex; + HASHMAP_FOREACH(l, m->links, i) { + LinkAddress *a; - return 0; + a = link_find_address(l, family, in_addr); + if (a) + return a; + } + + return NULL; } + +bool manager_our_packet(Manager *m, DnsPacket *p) { + assert(m); + assert(p); + + return !!manager_find_link_address(m, p->family, &p->sender); +} + +DnsScope* manager_find_scope(Manager *m, DnsPacket *p) { + Link *l; + + assert(m); + assert(p); + + l = hashmap_get(m->links, INT_TO_PTR(p->ifindex)); + if (!l) + return NULL; + + if (p->protocol == DNS_PROTOCOL_LLMNR) { + if (p->family == AF_INET) + return l->llmnr_ipv4_scope; + else if (p->family == AF_INET6) + return l->llmnr_ipv6_scope; + } + + return NULL; +} + +void manager_verify_all(Manager *m) { + DnsScope *s; + + assert(m); + + LIST_FOREACH(scopes, s, m->dns_scopes) + 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", + [SUPPORT_RESOLVE] = "resolve", +}; +DEFINE_STRING_TABLE_LOOKUP(support, Support);