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-rw-r--r--src/resolvers.c3813
1 files changed, 3813 insertions, 0 deletions
diff --git a/src/resolvers.c b/src/resolvers.c
new file mode 100644
index 0000000..3275cd2
--- /dev/null
+++ b/src/resolvers.c
@@ -0,0 +1,3813 @@
+/*
+ * Name server resolution
+ *
+ * Copyright 2014 Baptiste Assmann <bedis9@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <sys/types.h>
+
+#include <import/ebistree.h>
+
+#include <haproxy/action.h>
+#include <haproxy/api.h>
+#include <haproxy/applet.h>
+#include <haproxy/cfgparse.h>
+#include <haproxy/channel.h>
+#include <haproxy/check.h>
+#include <haproxy/cli.h>
+#include <haproxy/dns.h>
+#include <haproxy/errors.h>
+#include <haproxy/fd.h>
+#include <haproxy/http_rules.h>
+#include <haproxy/log.h>
+#include <haproxy/net_helper.h>
+#include <haproxy/protocol.h>
+#include <haproxy/proxy.h>
+#include <haproxy/resolvers.h>
+#include <haproxy/ring.h>
+#include <haproxy/sample.h>
+#include <haproxy/sc_strm.h>
+#include <haproxy/server.h>
+#include <haproxy/stats.h>
+#include <haproxy/stconn.h>
+#include <haproxy/task.h>
+#include <haproxy/tcp_rules.h>
+#include <haproxy/ticks.h>
+#include <haproxy/time.h>
+#include <haproxy/tools.h>
+#include <haproxy/vars.h>
+#include <haproxy/xxhash.h>
+
+
+struct list sec_resolvers = LIST_HEAD_INIT(sec_resolvers);
+struct list resolv_srvrq_list = LIST_HEAD_INIT(resolv_srvrq_list);
+
+static THREAD_LOCAL struct list death_row; /* list of deferred resolutions to kill, local validity only */
+static THREAD_LOCAL unsigned int recurse = 0; /* counter to track calls to public functions */
+static THREAD_LOCAL uint64_t resolv_query_id_seed = 0; /* random seed */
+struct resolvers *curr_resolvers = NULL;
+
+DECLARE_STATIC_POOL(resolv_answer_item_pool, "resolv_answer_item", sizeof(struct resolv_answer_item));
+DECLARE_STATIC_POOL(resolv_resolution_pool, "resolv_resolution", sizeof(struct resolv_resolution));
+DECLARE_POOL(resolv_requester_pool, "resolv_requester", sizeof(struct resolv_requester));
+
+static unsigned int resolution_uuid = 1;
+unsigned int resolv_failed_resolutions = 0;
+struct task *process_resolvers(struct task *t, void *context, unsigned int state);
+static void resolv_free_resolution(struct resolv_resolution *resolution);
+static void _resolv_unlink_resolution(struct resolv_requester *requester);
+static void enter_resolver_code();
+static void leave_resolver_code();
+
+enum {
+ RSLV_STAT_ID,
+ RSLV_STAT_PID,
+ RSLV_STAT_SENT,
+ RSLV_STAT_SND_ERROR,
+ RSLV_STAT_VALID,
+ RSLV_STAT_UPDATE,
+ RSLV_STAT_CNAME,
+ RSLV_STAT_CNAME_ERROR,
+ RSLV_STAT_ANY_ERR,
+ RSLV_STAT_NX,
+ RSLV_STAT_TIMEOUT,
+ RSLV_STAT_REFUSED,
+ RSLV_STAT_OTHER,
+ RSLV_STAT_INVALID,
+ RSLV_STAT_TOO_BIG,
+ RSLV_STAT_TRUNCATED,
+ RSLV_STAT_OUTDATED,
+ RSLV_STAT_END,
+};
+
+static struct name_desc resolv_stats[] = {
+ [RSLV_STAT_ID] = { .name = "id", .desc = "ID" },
+ [RSLV_STAT_PID] = { .name = "pid", .desc = "Parent ID" },
+ [RSLV_STAT_SENT] = { .name = "sent", .desc = "Sent" },
+ [RSLV_STAT_SND_ERROR] = { .name = "send_error", .desc = "Send error" },
+ [RSLV_STAT_VALID] = { .name = "valid", .desc = "Valid" },
+ [RSLV_STAT_UPDATE] = { .name = "update", .desc = "Update" },
+ [RSLV_STAT_CNAME] = { .name = "cname", .desc = "CNAME" },
+ [RSLV_STAT_CNAME_ERROR] = { .name = "cname_error", .desc = "CNAME error" },
+ [RSLV_STAT_ANY_ERR] = { .name = "any_err", .desc = "Any errors" },
+ [RSLV_STAT_NX] = { .name = "nx", .desc = "NX" },
+ [RSLV_STAT_TIMEOUT] = { .name = "timeout", .desc = "Timeout" },
+ [RSLV_STAT_REFUSED] = { .name = "refused", .desc = "Refused" },
+ [RSLV_STAT_OTHER] = { .name = "other", .desc = "Other" },
+ [RSLV_STAT_INVALID] = { .name = "invalid", .desc = "Invalid" },
+ [RSLV_STAT_TOO_BIG] = { .name = "too_big", .desc = "Too big" },
+ [RSLV_STAT_TRUNCATED] = { .name = "truncated", .desc = "Truncated" },
+ [RSLV_STAT_OUTDATED] = { .name = "outdated", .desc = "Outdated" },
+};
+
+static struct dns_counters dns_counters;
+
+static void resolv_fill_stats(void *d, struct field *stats)
+{
+ struct dns_counters *counters = d;
+ stats[RSLV_STAT_ID] = mkf_str(FO_CONFIG, counters->id);
+ stats[RSLV_STAT_PID] = mkf_str(FO_CONFIG, counters->pid);
+ stats[RSLV_STAT_SENT] = mkf_u64(FN_GAUGE, counters->sent);
+ stats[RSLV_STAT_SND_ERROR] = mkf_u64(FN_GAUGE, counters->snd_error);
+ stats[RSLV_STAT_VALID] = mkf_u64(FN_GAUGE, counters->app.resolver.valid);
+ stats[RSLV_STAT_UPDATE] = mkf_u64(FN_GAUGE, counters->app.resolver.update);
+ stats[RSLV_STAT_CNAME] = mkf_u64(FN_GAUGE, counters->app.resolver.cname);
+ stats[RSLV_STAT_CNAME_ERROR] = mkf_u64(FN_GAUGE, counters->app.resolver.cname_error);
+ stats[RSLV_STAT_ANY_ERR] = mkf_u64(FN_GAUGE, counters->app.resolver.any_err);
+ stats[RSLV_STAT_NX] = mkf_u64(FN_GAUGE, counters->app.resolver.nx);
+ stats[RSLV_STAT_TIMEOUT] = mkf_u64(FN_GAUGE, counters->app.resolver.timeout);
+ stats[RSLV_STAT_REFUSED] = mkf_u64(FN_GAUGE, counters->app.resolver.refused);
+ stats[RSLV_STAT_OTHER] = mkf_u64(FN_GAUGE, counters->app.resolver.other);
+ stats[RSLV_STAT_INVALID] = mkf_u64(FN_GAUGE, counters->app.resolver.invalid);
+ stats[RSLV_STAT_TOO_BIG] = mkf_u64(FN_GAUGE, counters->app.resolver.too_big);
+ stats[RSLV_STAT_TRUNCATED] = mkf_u64(FN_GAUGE, counters->app.resolver.truncated);
+ stats[RSLV_STAT_OUTDATED] = mkf_u64(FN_GAUGE, counters->app.resolver.outdated);
+}
+
+static struct stats_module rslv_stats_module = {
+ .name = "resolvers",
+ .domain_flags = STATS_DOMAIN_RESOLVERS << STATS_DOMAIN,
+ .fill_stats = resolv_fill_stats,
+ .stats = resolv_stats,
+ .stats_count = RSLV_STAT_END,
+ .counters = &dns_counters,
+ .counters_size = sizeof(dns_counters),
+ .clearable = 0,
+};
+
+INITCALL1(STG_REGISTER, stats_register_module, &rslv_stats_module);
+
+/* CLI context used during "show resolvers" */
+struct show_resolvers_ctx {
+ struct resolvers *forced_section;
+ struct resolvers *resolvers;
+ struct dns_nameserver *ns;
+};
+
+/* Returns a pointer to the resolvers matching the id <id>. NULL is returned if
+ * no match is found.
+ */
+struct resolvers *find_resolvers_by_id(const char *id)
+{
+ struct resolvers *res;
+
+ list_for_each_entry(res, &sec_resolvers, list) {
+ if (strcmp(res->id, id) == 0)
+ return res;
+ }
+ return NULL;
+}
+
+/* Returns a pointer on the SRV request matching the name <name> for the proxy
+ * <px>. NULL is returned if no match is found.
+ */
+struct resolv_srvrq *find_srvrq_by_name(const char *name, struct proxy *px)
+{
+ struct resolv_srvrq *srvrq;
+
+ list_for_each_entry(srvrq, &resolv_srvrq_list, list) {
+ if (srvrq->proxy == px && strcmp(srvrq->name, name) == 0)
+ return srvrq;
+ }
+ return NULL;
+}
+
+/* Allocates a new SRVRQ for the given server with the name <fqdn>. It returns
+ * NULL if an error occurred. */
+struct resolv_srvrq *new_resolv_srvrq(struct server *srv, char *fqdn)
+{
+ struct proxy *px = srv->proxy;
+ struct resolv_srvrq *srvrq = NULL;
+ int fqdn_len, hostname_dn_len;
+
+ fqdn_len = strlen(fqdn);
+ hostname_dn_len = resolv_str_to_dn_label(fqdn, fqdn_len, trash.area,
+ trash.size);
+ if (hostname_dn_len == -1) {
+ ha_alert("%s '%s', server '%s': failed to parse FQDN '%s'\n",
+ proxy_type_str(px), px->id, srv->id, fqdn);
+ goto err;
+ }
+
+ if ((srvrq = calloc(1, sizeof(*srvrq))) == NULL) {
+ ha_alert("%s '%s', server '%s': out of memory\n",
+ proxy_type_str(px), px->id, srv->id);
+ goto err;
+ }
+ srvrq->obj_type = OBJ_TYPE_SRVRQ;
+ srvrq->proxy = px;
+ srvrq->name = strdup(fqdn);
+ srvrq->hostname_dn = strdup(trash.area);
+ srvrq->hostname_dn_len = hostname_dn_len;
+ if (!srvrq->name || !srvrq->hostname_dn) {
+ ha_alert("%s '%s', server '%s': out of memory\n",
+ proxy_type_str(px), px->id, srv->id);
+ goto err;
+ }
+ LIST_INIT(&srvrq->attached_servers);
+ srvrq->named_servers = EB_ROOT;
+ LIST_APPEND(&resolv_srvrq_list, &srvrq->list);
+ return srvrq;
+
+ err:
+ if (srvrq) {
+ free(srvrq->name);
+ free(srvrq->hostname_dn);
+ free(srvrq);
+ }
+ return NULL;
+}
+
+
+/* finds and return the SRV answer item associated to a requester (whose type is 'server').
+ *
+ * returns NULL in case of error or not found.
+ */
+struct resolv_answer_item *find_srvrq_answer_record(const struct resolv_requester *requester)
+{
+ struct resolv_resolution *res;
+ struct eb32_node *eb32;
+ struct server *srv;
+
+ if (!requester)
+ return NULL;
+
+ if ((srv = objt_server(requester->owner)) == NULL)
+ return NULL;
+ /* check if the server is managed by a SRV record */
+ if (srv->srvrq == NULL)
+ return NULL;
+
+ res = srv->srvrq->requester->resolution;
+
+ /* search an ANSWER record whose target points to the server's hostname and whose port is
+ * the same as server's svc_port */
+ for (eb32 = eb32_first(&res->response.answer_tree); eb32 != NULL; eb32 = eb32_next(eb32)) {
+ struct resolv_answer_item *item = eb32_entry(eb32, typeof(*item), link);
+
+ if (memcmp(srv->hostname_dn, item->data.target, srv->hostname_dn_len) == 0 &&
+ (srv->svc_port == item->port))
+ return item;
+ }
+
+ return NULL;
+}
+
+/* 2 bytes random generator to generate DNS query ID */
+static inline uint16_t resolv_rnd16(void)
+{
+ if (!resolv_query_id_seed)
+ resolv_query_id_seed = now_ms;
+ resolv_query_id_seed ^= resolv_query_id_seed << 13;
+ resolv_query_id_seed ^= resolv_query_id_seed >> 7;
+ resolv_query_id_seed ^= resolv_query_id_seed << 17;
+ return resolv_query_id_seed;
+}
+
+
+static inline int resolv_resolution_timeout(struct resolv_resolution *res)
+{
+ return res->resolvers->timeout.resolve;
+}
+
+/* Updates a resolvers' task timeout for next wake up and queue it */
+static void resolv_update_resolvers_timeout(struct resolvers *resolvers)
+{
+ struct resolv_resolution *res;
+ int next = TICK_ETERNITY;
+
+ if (!LIST_ISEMPTY(&resolvers->resolutions.curr)) {
+ res = LIST_NEXT(&resolvers->resolutions.curr, struct resolv_resolution *, list);
+ next = tick_add(now_ms, resolvers->timeout.resolve);
+ next = tick_first(next, tick_add(res->last_query, resolvers->timeout.retry));
+ }
+
+ list_for_each_entry(res, &resolvers->resolutions.wait, list)
+ next = tick_first(next, tick_add(res->last_resolution, resolv_resolution_timeout(res)));
+
+ resolvers->t->expire = next;
+ task_queue(resolvers->t);
+}
+
+/* Forges a DNS query. It needs the following information from the caller:
+ * - <query_id> : the DNS query id corresponding to this query
+ * - <query_type> : DNS_RTYPE_* request DNS record type (A, AAAA, ANY...)
+ * - <hostname_dn> : hostname in domain name format
+ * - <hostname_dn_len> : length of <hostname_dn>
+ *
+ * To store the query, the caller must pass a buffer <buf> and its size
+ * <bufsize>. It returns the number of written bytes in success, -1 if <buf> is
+ * too short.
+ */
+static int resolv_build_query(int query_id, int query_type, unsigned int accepted_payload_size,
+ char *hostname_dn, int hostname_dn_len, char *buf, int bufsize)
+{
+ struct dns_header dns_hdr;
+ struct dns_question qinfo;
+ struct dns_additional_record edns;
+ char *p = buf;
+
+ if (sizeof(dns_hdr) + sizeof(qinfo) + sizeof(edns) + hostname_dn_len >= bufsize)
+ return -1;
+
+ memset(buf, 0, bufsize);
+
+ /* Set dns query headers */
+ dns_hdr.id = (unsigned short) htons(query_id);
+ dns_hdr.flags = htons(0x0100); /* qr=0, opcode=0, aa=0, tc=0, rd=1, ra=0, z=0, rcode=0 */
+ dns_hdr.qdcount = htons(1); /* 1 question */
+ dns_hdr.ancount = 0;
+ dns_hdr.nscount = 0;
+ dns_hdr.arcount = htons(1);
+ memcpy(p, &dns_hdr, sizeof(dns_hdr));
+ p += sizeof(dns_hdr);
+
+ /* Set up query hostname */
+ memcpy(p, hostname_dn, hostname_dn_len);
+ p += hostname_dn_len;
+ *p++ = 0;
+
+ /* Set up query info (type and class) */
+ qinfo.qtype = htons(query_type);
+ qinfo.qclass = htons(DNS_RCLASS_IN);
+ memcpy(p, &qinfo, sizeof(qinfo));
+ p += sizeof(qinfo);
+
+ /* Set the DNS extension */
+ edns.name = 0;
+ edns.type = htons(DNS_RTYPE_OPT);
+ edns.udp_payload_size = htons(accepted_payload_size);
+ edns.extension = 0;
+ edns.data_length = 0;
+ memcpy(p, &edns, sizeof(edns));
+ p += sizeof(edns);
+
+ return (p - buf);
+}
+
+/* Sends a DNS query to resolvers associated to a resolution. It returns 0 on
+ * success or -1 if trash buffer is not large enough to build a valid query.
+ */
+static int resolv_send_query(struct resolv_resolution *resolution)
+{
+ struct resolvers *resolvers = resolution->resolvers;
+ struct dns_nameserver *ns;
+ int len;
+
+ /* Update resolution */
+ resolution->nb_queries = 0;
+ resolution->nb_responses = 0;
+ resolution->last_query = now_ms;
+
+ len = resolv_build_query(resolution->query_id, resolution->query_type,
+ resolvers->accepted_payload_size,
+ resolution->hostname_dn, resolution->hostname_dn_len,
+ trash.area, trash.size);
+ if (len < 0) {
+ send_log(NULL, LOG_NOTICE,
+ "can not build the query message for %s, in resolvers %s.\n",
+ resolution->hostname_dn, resolvers->id);
+ return -1;
+ }
+
+ list_for_each_entry(ns, &resolvers->nameservers, list) {
+ if (dns_send_nameserver(ns, trash.area, len) >= 0)
+ resolution->nb_queries++;
+ }
+
+ /* Push the resolution at the end of the active list */
+ LIST_DEL_INIT(&resolution->list);
+ LIST_APPEND(&resolvers->resolutions.curr, &resolution->list);
+ return 0;
+}
+
+/* Prepares and sends a DNS resolution. It returns 1 if the query was sent, 0 if
+ * skipped and -1 if an error occurred.
+ */
+static int
+resolv_run_resolution(struct resolv_resolution *resolution)
+{
+ struct resolvers *resolvers = resolution->resolvers;
+ int query_id, i;
+
+ /* Avoid sending requests for resolutions that don't yet have an
+ * hostname, ie resolutions linked to servers that do not yet have an
+ * fqdn */
+ if (!resolution->hostname_dn)
+ return 0;
+
+ /* Check if a resolution has already been started for this server return
+ * directly to avoid resolution pill up. */
+ if (resolution->step != RSLV_STEP_NONE)
+ return 0;
+
+ /* Generates a new query id. We try at most 100 times to find a free
+ * query id */
+ for (i = 0; i < 100; ++i) {
+ query_id = resolv_rnd16();
+ if (!eb32_lookup(&resolvers->query_ids, query_id))
+ break;
+ query_id = -1;
+ }
+ if (query_id == -1) {
+ send_log(NULL, LOG_NOTICE,
+ "could not generate a query id for %s, in resolvers %s.\n",
+ resolution->hostname_dn, resolvers->id);
+ return -1;
+ }
+
+ /* Update resolution parameters */
+ resolution->query_id = query_id;
+ resolution->qid.key = query_id;
+ resolution->step = RSLV_STEP_RUNNING;
+ resolution->query_type = resolution->prefered_query_type;
+ resolution->try = resolvers->resolve_retries;
+ eb32_insert(&resolvers->query_ids, &resolution->qid);
+
+ /* Send the DNS query */
+ resolution->try -= 1;
+ resolv_send_query(resolution);
+ return 1;
+}
+
+/* Performs a name resolution for the requester <req> */
+void resolv_trigger_resolution(struct resolv_requester *req)
+{
+ struct resolvers *resolvers;
+ struct resolv_resolution *res;
+ int exp;
+
+ if (!req || !req->resolution)
+ return;
+ res = req->resolution;
+ resolvers = res->resolvers;
+
+ enter_resolver_code();
+
+ /* The resolution must not be triggered yet. Use the cached response, if
+ * valid */
+ exp = tick_add(res->last_resolution, resolvers->hold.valid);
+ if (resolvers->t && (!tick_isset(resolvers->t->expire) || res->status != RSLV_STATUS_VALID ||
+ !tick_isset(res->last_resolution) || tick_is_expired(exp, now_ms))) {
+ /* If the resolution is not running and the requester is a
+ * server, reset the resolution timer to force a quick
+ * resolution.
+ */
+ if (res->step == RSLV_STEP_NONE &&
+ (obj_type(req->owner) == OBJ_TYPE_SERVER ||
+ obj_type(req->owner) == OBJ_TYPE_SRVRQ))
+ res->last_resolution = TICK_ETERNITY;
+ task_wakeup(resolvers->t, TASK_WOKEN_OTHER);
+ }
+
+ leave_resolver_code();
+}
+
+
+/* Resets some resolution parameters to initial values and also delete the query
+ * ID from the resolver's tree.
+ */
+static void resolv_reset_resolution(struct resolv_resolution *resolution)
+{
+ /* update resolution status */
+ resolution->step = RSLV_STEP_NONE;
+ resolution->try = 0;
+ resolution->last_resolution = now_ms;
+ resolution->nb_queries = 0;
+ resolution->nb_responses = 0;
+ resolution->query_type = resolution->prefered_query_type;
+
+ /* clean up query id */
+ eb32_delete(&resolution->qid);
+ resolution->query_id = 0;
+ resolution->qid.key = 0;
+}
+
+/* Returns the query id contained in a DNS response */
+static inline unsigned short resolv_response_get_query_id(unsigned char *resp)
+{
+ return resp[0] * 256 + resp[1];
+}
+
+
+/* Analyses, re-builds and copies the name <name> from the DNS response packet
+ * <buffer>. <name> must point to the 'data_len' information or pointer 'c0'
+ * for compressed data. The result is copied into <dest>, ensuring we don't
+ * overflow using <dest_len> Returns the number of bytes the caller can move
+ * forward. If 0 it means an error occurred while parsing the name. <offset> is
+ * the number of bytes the caller could move forward.
+ */
+int resolv_read_name(unsigned char *buffer, unsigned char *bufend,
+ unsigned char *name, char *destination, int dest_len,
+ int *offset, unsigned int depth)
+{
+ int nb_bytes = 0, n = 0;
+ int label_len;
+ unsigned char *reader = name;
+ char *dest = destination;
+
+ while (1) {
+ if (reader >= bufend)
+ goto err;
+
+ /* Name compression is in use */
+ if ((*reader & 0xc0) == 0xc0) {
+ if (reader + 1 >= bufend)
+ goto err;
+
+ /* Must point BEFORE current position */
+ if ((buffer + reader[1]) > reader)
+ goto err;
+
+ if (depth++ > 100)
+ goto err;
+
+ n = resolv_read_name(buffer, bufend, buffer + (*reader & 0x3f)*256 + reader[1],
+ dest, dest_len - nb_bytes, offset, depth);
+ if (n == 0)
+ goto err;
+
+ dest += n;
+ nb_bytes += n;
+ goto out;
+ }
+
+ label_len = *reader;
+ if (label_len == 0)
+ goto out;
+
+ /* Check if:
+ * - we won't read outside the buffer
+ * - there is enough place in the destination
+ */
+ if ((reader + label_len >= bufend) || (nb_bytes + label_len >= dest_len))
+ goto err;
+
+ /* +1 to take label len + label string */
+ label_len++;
+
+ memcpy(dest, reader, label_len);
+
+ dest += label_len;
+ nb_bytes += label_len;
+ reader += label_len;
+ }
+
+ out:
+ /* offset computation:
+ * parse from <name> until finding either NULL or a pointer "c0xx"
+ */
+ reader = name;
+ *offset = 0;
+ while (reader < bufend) {
+ if ((reader[0] & 0xc0) == 0xc0) {
+ *offset += 2;
+ break;
+ }
+ else if (*reader == 0) {
+ *offset += 1;
+ break;
+ }
+ *offset += 1;
+ ++reader;
+ }
+ return nb_bytes;
+
+ err:
+ return 0;
+}
+
+/* Reinitialize the list of aborted resolutions before calling certain
+ * functions relying on it. The list must be processed by calling
+ * leave_resolver_code() after operations.
+ */
+static void enter_resolver_code()
+{
+ if (!recurse)
+ LIST_INIT(&death_row);
+ recurse++;
+}
+
+/* Add a resolution to the death_row. */
+static void abort_resolution(struct resolv_resolution *res)
+{
+ /* Remove the resolution from query_ids tree and from any resolvers list */
+ eb32_delete(&res->qid);
+ res->query_id = 0;
+ res->qid.key = 0;
+
+ LIST_DEL_INIT(&res->list);
+ LIST_APPEND(&death_row, &res->list);
+}
+
+/* This releases any aborted resolution found in the death row. It is mandatory
+ * to call enter_resolver_code() first before the function (or loop) that
+ * needs to defer deletions. Note that some of them are in relation via internal
+ * objects and might cause the deletion of other ones from the same list, so we
+ * must absolutely not use a list_for_each_entry_safe() nor any such thing here,
+ * and solely rely on each call to remove the first remaining list element.
+ */
+static void leave_resolver_code()
+{
+ struct resolv_resolution *res;
+
+ recurse--;
+ if (recurse)
+ return;
+
+ while (!LIST_ISEMPTY(&death_row)) {
+ res = LIST_NEXT(&death_row, struct resolv_resolution *, list);
+ resolv_free_resolution(res);
+ }
+
+ /* make sure nobody tries to add anything without having initialized it */
+ death_row = (struct list){ };
+}
+
+/* Cleanup fqdn/port and address of a server attached to a SRV resolution. This
+ * happens when an SRV item is purged or when the server status is considered as
+ * obsolete.
+ *
+ * Must be called with the DNS lock held, and with the death_row already
+ * initialized via enter_resolver_code().
+ */
+static void resolv_srvrq_cleanup_srv(struct server *srv)
+{
+ _resolv_unlink_resolution(srv->resolv_requester);
+ HA_SPIN_LOCK(SERVER_LOCK, &srv->lock);
+ srvrq_update_srv_status(srv, 1);
+ ha_free(&srv->hostname);
+ ha_free(&srv->hostname_dn);
+ srv->hostname_dn_len = 0;
+ memset(&srv->addr, 0, sizeof(srv->addr));
+ srv->svc_port = 0;
+ srv->flags |= SRV_F_NO_RESOLUTION;
+
+ ebpt_delete(&srv->host_dn);
+ ha_free(&srv->host_dn.key);
+
+ HA_SPIN_UNLOCK(SERVER_LOCK, &srv->lock);
+ LIST_DEL_INIT(&srv->srv_rec_item);
+ LIST_APPEND(&srv->srvrq->attached_servers, &srv->srv_rec_item);
+
+ srv->srvrq_check->expire = TICK_ETERNITY;
+}
+
+/* Takes care to cleanup a server resolution when it is outdated. This only
+ * happens for a server relying on a SRV record.
+ */
+static struct task *resolv_srvrq_expire_task(struct task *t, void *context, unsigned int state)
+{
+ struct server *srv = context;
+
+ if (!tick_is_expired(t->expire, now_ms))
+ goto end;
+
+ enter_resolver_code();
+ HA_SPIN_LOCK(DNS_LOCK, &srv->srvrq->resolvers->lock);
+ resolv_srvrq_cleanup_srv(srv);
+ HA_SPIN_UNLOCK(DNS_LOCK, &srv->srvrq->resolvers->lock);
+ leave_resolver_code();
+
+ end:
+ return t;
+}
+
+/* Checks for any obsolete record, also identify any SRV request, and try to
+ * find a corresponding server.
+ */
+static void resolv_check_response(struct resolv_resolution *res)
+{
+ struct resolvers *resolvers = res->resolvers;
+ struct resolv_requester *req;
+ struct eb32_node *eb32, *eb32_back;
+ struct server *srv, *srvback;
+ struct resolv_srvrq *srvrq;
+
+ for (eb32 = eb32_first(&res->response.answer_tree); eb32 && (eb32_back = eb32_next(eb32), 1); eb32 = eb32_back) {
+ struct resolv_answer_item *item = eb32_entry(eb32, typeof(*item), link);
+ struct resolv_answer_item *ar_item = item->ar_item;
+
+ /* clean up obsolete Additional record */
+ if (ar_item && tick_is_lt(tick_add(ar_item->last_seen, resolvers->hold.obsolete), now_ms)) {
+ /* Cleaning up the AR item will trigger an extra DNS resolution, except if the SRV
+ * item is also obsolete.
+ */
+ pool_free(resolv_answer_item_pool, ar_item);
+ item->ar_item = NULL;
+ }
+
+ /* Remove obsolete items */
+ if (tick_is_lt(tick_add(item->last_seen, resolvers->hold.obsolete), now_ms)) {
+ if (item->type == DNS_RTYPE_A || item->type == DNS_RTYPE_AAAA) {
+ /* Remove any associated server */
+ list_for_each_entry_safe(srv, srvback, &item->attached_servers, ip_rec_item) {
+ LIST_DEL_INIT(&srv->ip_rec_item);
+ }
+ }
+ else if (item->type == DNS_RTYPE_SRV) {
+ /* Remove any associated server */
+ list_for_each_entry_safe(srv, srvback, &item->attached_servers, srv_rec_item)
+ resolv_srvrq_cleanup_srv(srv);
+ }
+
+ eb32_delete(&item->link);
+ if (item->ar_item) {
+ pool_free(resolv_answer_item_pool, item->ar_item);
+ item->ar_item = NULL;
+ }
+ pool_free(resolv_answer_item_pool, item);
+ continue;
+ }
+
+ if (item->type != DNS_RTYPE_SRV)
+ continue;
+
+ /* Now process SRV records */
+ list_for_each_entry(req, &res->requesters, list) {
+ struct ebpt_node *node;
+ char target[DNS_MAX_NAME_SIZE+1];
+
+ int i;
+ if ((srvrq = objt_resolv_srvrq(req->owner)) == NULL)
+ continue;
+
+ /* Check if a server already uses that record */
+ srv = NULL;
+ list_for_each_entry(srv, &item->attached_servers, srv_rec_item) {
+ if (srv->srvrq == srvrq) {
+ HA_SPIN_LOCK(SERVER_LOCK, &srv->lock);
+ goto srv_found;
+ }
+ }
+
+
+ /* If not empty we try to match a server
+ * in server state file tree with the same hostname
+ */
+ if (!eb_is_empty(&srvrq->named_servers)) {
+ srv = NULL;
+
+ /* convert the key to lookup in lower case */
+ for (i = 0 ; item->data.target[i] ; i++)
+ target[i] = tolower(item->data.target[i]);
+ target[i] = 0;
+
+ node = ebis_lookup(&srvrq->named_servers, target);
+ if (node) {
+ srv = ebpt_entry(node, struct server, host_dn);
+ HA_SPIN_LOCK(SERVER_LOCK, &srv->lock);
+
+ /* an entry was found with the same hostname
+ * let check this node if the port matches
+ * and try next node if the hostname
+ * is still the same
+ */
+ while (1) {
+ if (srv->svc_port == item->port) {
+ /* server found, we remove it from tree */
+ ebpt_delete(node);
+ ha_free(&srv->host_dn.key);
+ goto srv_found;
+ }
+
+ HA_SPIN_UNLOCK(SERVER_LOCK, &srv->lock);
+
+ node = ebpt_next(node);
+ if (!node)
+ break;
+
+ srv = ebpt_entry(node, struct server, host_dn);
+ HA_SPIN_LOCK(SERVER_LOCK, &srv->lock);
+
+ if ((item->data_len != srv->hostname_dn_len)
+ || memcmp(srv->hostname_dn, item->data.target, item->data_len) != 0) {
+ HA_SPIN_UNLOCK(SERVER_LOCK, &srv->lock);
+ break;
+ }
+ }
+ }
+ }
+
+ /* Pick the first server listed in srvrq (those ones don't
+ * have hostname and are free to use)
+ */
+ srv = NULL;
+ list_for_each_entry(srv, &srvrq->attached_servers, srv_rec_item) {
+ LIST_DEL_INIT(&srv->srv_rec_item);
+ HA_SPIN_LOCK(SERVER_LOCK, &srv->lock);
+ goto srv_found;
+ }
+ srv = NULL;
+
+srv_found:
+ /* And update this server, if found (srv is locked here) */
+ if (srv) {
+ /* re-enable DNS resolution for this server by default */
+ srv->flags &= ~SRV_F_NO_RESOLUTION;
+ srv->srvrq_check->expire = TICK_ETERNITY;
+
+ srv->svc_port = item->port;
+ srv->flags &= ~SRV_F_MAPPORTS;
+
+ /* Check if an Additional Record is associated to this SRV record.
+ * Perform some sanity checks too to ensure the record can be used.
+ * If all fine, we simply pick up the IP address found and associate
+ * it to the server. And DNS resolution is disabled for this server.
+ */
+ if ((item->ar_item != NULL) &&
+ (item->ar_item->type == DNS_RTYPE_A || item->ar_item->type == DNS_RTYPE_AAAA))
+ {
+
+ switch (item->ar_item->type) {
+ case DNS_RTYPE_A:
+ srv_update_addr(srv, &item->ar_item->data.in4.sin_addr, AF_INET, "DNS additional record");
+ break;
+ case DNS_RTYPE_AAAA:
+ srv_update_addr(srv, &item->ar_item->data.in6.sin6_addr, AF_INET6, "DNS additional record");
+ break;
+ }
+
+ srv->flags |= SRV_F_NO_RESOLUTION;
+
+ /* Unlink A/AAAA resolution for this server if there is an AR item.
+ * It is usless to perform an extra resolution
+ */
+ _resolv_unlink_resolution(srv->resolv_requester);
+ }
+
+ if (!srv->hostname_dn) {
+ const char *msg = NULL;
+ char hostname[DNS_MAX_NAME_SIZE+1];
+
+ if (resolv_dn_label_to_str(item->data.target, item->data_len,
+ hostname, sizeof(hostname)) == -1) {
+ HA_SPIN_UNLOCK(SERVER_LOCK, &srv->lock);
+ continue;
+ }
+ msg = srv_update_fqdn(srv, hostname, "SRV record", 1);
+ if (msg)
+ send_log(srv->proxy, LOG_NOTICE, "%s", msg);
+ }
+
+ if (!LIST_INLIST(&srv->srv_rec_item))
+ LIST_APPEND(&item->attached_servers, &srv->srv_rec_item);
+
+ if (!(srv->flags & SRV_F_NO_RESOLUTION)) {
+ /* If there is no AR item responsible of the FQDN resolution,
+ * trigger a dedicated DNS resolution
+ */
+ if (!srv->resolv_requester || !srv->resolv_requester->resolution)
+ resolv_link_resolution(srv, OBJ_TYPE_SERVER, 1);
+ }
+
+ /* Update the server status */
+ srvrq_update_srv_status(srv, (srv->addr.ss_family != AF_INET && srv->addr.ss_family != AF_INET6));
+
+ if (!srv->resolv_opts.ignore_weight) {
+ char weight[9];
+ int ha_weight;
+
+ /* DNS weight range if from 0 to 65535
+ * HAProxy weight is from 0 to 256
+ * The rule below ensures that weight 0 is well respected
+ * while allowing a "mapping" from DNS weight into HAProxy's one.
+ */
+ ha_weight = (item->weight + 255) / 256;
+
+ snprintf(weight, sizeof(weight), "%d", ha_weight);
+ server_parse_weight_change_request(srv, weight);
+ }
+ HA_SPIN_UNLOCK(SERVER_LOCK, &srv->lock);
+ }
+ }
+ }
+}
+
+/* Validates that the buffer DNS response provided in <resp> and finishing
+ * before <bufend> is valid from a DNS protocol point of view.
+ *
+ * The result is stored in <resolution>' response, buf_response,
+ * response_query_records and response_answer_records members.
+ *
+ * This function returns one of the RSLV_RESP_* code to indicate the type of
+ * error found.
+ */
+static int resolv_validate_dns_response(unsigned char *resp, unsigned char *bufend,
+ struct resolv_resolution *resolution, int max_answer_records)
+{
+ unsigned char *reader;
+ char *previous_dname, tmpname[DNS_MAX_NAME_SIZE];
+ int len, flags, offset;
+ int nb_saved_records;
+ struct resolv_query_item *query;
+ struct resolv_answer_item *answer_record, *tmp_record;
+ struct resolv_response *r_res;
+ struct eb32_node *eb32;
+ uint32_t key = 0;
+ int i, found = 0;
+ int cause = RSLV_RESP_ERROR;
+
+ reader = resp;
+ len = 0;
+ previous_dname = NULL;
+ query = NULL;
+ answer_record = NULL;
+
+ /* Initialization of response buffer and structure */
+ r_res = &resolution->response;
+
+ /* query id */
+ if (reader + 2 >= bufend)
+ goto invalid_resp;
+
+ r_res->header.id = reader[0] * 256 + reader[1];
+ reader += 2;
+
+ /* Flags and rcode are stored over 2 bytes
+ * First byte contains:
+ * - response flag (1 bit)
+ * - opcode (4 bits)
+ * - authoritative (1 bit)
+ * - truncated (1 bit)
+ * - recursion desired (1 bit)
+ */
+ if (reader + 2 >= bufend)
+ goto invalid_resp;
+
+ flags = reader[0] * 256 + reader[1];
+
+ if ((flags & DNS_FLAG_REPLYCODE) != DNS_RCODE_NO_ERROR) {
+ if ((flags & DNS_FLAG_REPLYCODE) == DNS_RCODE_NX_DOMAIN) {
+ cause = RSLV_RESP_NX_DOMAIN;
+ goto return_error;
+ }
+ else if ((flags & DNS_FLAG_REPLYCODE) == DNS_RCODE_REFUSED) {
+ cause = RSLV_RESP_REFUSED;
+ goto return_error;
+ }
+ else {
+ cause = RSLV_RESP_ERROR;
+ goto return_error;
+ }
+ }
+
+ /* Move forward 2 bytes for flags */
+ reader += 2;
+
+ /* 2 bytes for question count */
+ if (reader + 2 >= bufend)
+ goto invalid_resp;
+ r_res->header.qdcount = reader[0] * 256 + reader[1];
+ /* (for now) we send one query only, so we expect only one in the
+ * response too */
+ if (r_res->header.qdcount != 1) {
+ cause = RSLV_RESP_QUERY_COUNT_ERROR;
+ goto return_error;
+ }
+
+ if (r_res->header.qdcount > DNS_MAX_QUERY_RECORDS)
+ goto invalid_resp;
+ reader += 2;
+
+ /* 2 bytes for answer count */
+ if (reader + 2 >= bufend)
+ goto invalid_resp;
+ r_res->header.ancount = reader[0] * 256 + reader[1];
+ if (r_res->header.ancount == 0) {
+ cause = RSLV_RESP_ANCOUNT_ZERO;
+ goto return_error;
+ }
+
+ /* Check if too many records are announced */
+ if (r_res->header.ancount > max_answer_records)
+ goto invalid_resp;
+ reader += 2;
+
+ /* 2 bytes authority count */
+ if (reader + 2 >= bufend)
+ goto invalid_resp;
+ r_res->header.nscount = reader[0] * 256 + reader[1];
+ reader += 2;
+
+ /* 2 bytes additional count */
+ if (reader + 2 >= bufend)
+ goto invalid_resp;
+ r_res->header.arcount = reader[0] * 256 + reader[1];
+ reader += 2;
+
+ /* Parsing dns queries. For now there is only one query and it exists
+ * because (qdcount == 1).
+ */
+ query = &resolution->response_query_records[0];
+
+ /* Name is a NULL terminated string in our case, since we have
+ * one query per response and the first one can't be compressed
+ * (using the 0x0c format) */
+ offset = 0;
+ len = resolv_read_name(resp, bufend, reader, query->name, DNS_MAX_NAME_SIZE, &offset, 0);
+
+ if (len == 0)
+ goto invalid_resp;
+
+ /* Now let's check the query's dname corresponds to the one we sent. */
+ if (len != resolution->hostname_dn_len ||
+ memcmp(query->name, resolution->hostname_dn, resolution->hostname_dn_len) != 0) {
+ cause = RSLV_RESP_WRONG_NAME;
+ goto return_error;
+ }
+
+ reader += offset;
+ previous_dname = query->name;
+
+ /* move forward 2 bytes for question type */
+ if (reader + 2 >= bufend)
+ goto invalid_resp;
+ query->type = reader[0] * 256 + reader[1];
+ reader += 2;
+
+ /* move forward 2 bytes for question class */
+ if (reader + 2 >= bufend)
+ goto invalid_resp;
+ query->class = reader[0] * 256 + reader[1];
+ reader += 2;
+
+ /* TRUNCATED flag must be checked after we could read the query type
+ * because a TRUNCATED SRV query type response can still be exploited
+ */
+ if (query->type != DNS_RTYPE_SRV && flags & DNS_FLAG_TRUNCATED) {
+ cause = RSLV_RESP_TRUNCATED;
+ goto return_error;
+ }
+
+ /* now parsing response records */
+ nb_saved_records = 0;
+ for (i = 0; i < r_res->header.ancount; i++) {
+ if (reader >= bufend)
+ goto invalid_resp;
+
+ answer_record = pool_alloc(resolv_answer_item_pool);
+ if (answer_record == NULL)
+ goto invalid_resp;
+
+ /* initialization */
+ answer_record->ar_item = NULL;
+ answer_record->last_seen = TICK_ETERNITY;
+ LIST_INIT(&answer_record->attached_servers);
+ answer_record->link.node.leaf_p = NULL;
+
+ offset = 0;
+ len = resolv_read_name(resp, bufend, reader, tmpname, DNS_MAX_NAME_SIZE, &offset, 0);
+
+ if (len == 0)
+ goto invalid_resp;
+
+ /* Check if the current record dname is valid. previous_dname
+ * points either to queried dname or last CNAME target */
+ if (query->type != DNS_RTYPE_SRV && memcmp(previous_dname, tmpname, len) != 0) {
+ if (i == 0) {
+ /* First record, means a mismatch issue between
+ * queried dname and dname found in the first
+ * record */
+ goto invalid_resp;
+ }
+ else {
+ /* If not the first record, this means we have a
+ * CNAME resolution error.
+ */
+ cause = RSLV_RESP_CNAME_ERROR;
+ goto return_error;
+ }
+
+ }
+
+ memcpy(answer_record->name, tmpname, len);
+ answer_record->name[len] = 0;
+
+ reader += offset;
+ if (reader >= bufend)
+ goto invalid_resp;
+
+ /* 2 bytes for record type (A, AAAA, CNAME, etc...) */
+ if (reader + 2 > bufend)
+ goto invalid_resp;
+
+ answer_record->type = reader[0] * 256 + reader[1];
+ reader += 2;
+
+ /* 2 bytes for class (2) */
+ if (reader + 2 > bufend)
+ goto invalid_resp;
+
+ answer_record->class = reader[0] * 256 + reader[1];
+ reader += 2;
+
+ /* 4 bytes for ttl (4) */
+ if (reader + 4 > bufend)
+ goto invalid_resp;
+
+ answer_record->ttl = reader[0] * 16777216 + reader[1] * 65536
+ + reader[2] * 256 + reader[3];
+ reader += 4;
+
+ /* Now reading data len */
+ if (reader + 2 > bufend)
+ goto invalid_resp;
+
+ answer_record->data_len = reader[0] * 256 + reader[1];
+
+ /* Move forward 2 bytes for data len */
+ reader += 2;
+
+ if (reader + answer_record->data_len > bufend)
+ goto invalid_resp;
+
+ /* Analyzing record content */
+ switch (answer_record->type) {
+ case DNS_RTYPE_A:
+ /* ipv4 is stored on 4 bytes */
+ if (answer_record->data_len != 4)
+ goto invalid_resp;
+
+ answer_record->data.in4.sin_family = AF_INET;
+ memcpy(&answer_record->data.in4.sin_addr, reader, answer_record->data_len);
+ key = XXH32(reader, answer_record->data_len, answer_record->type);
+ break;
+
+ case DNS_RTYPE_CNAME:
+ /* Check if this is the last record and update the caller about the status:
+ * no IP could be found and last record was a CNAME. Could be triggered
+ * by a wrong query type
+ *
+ * + 1 because answer_record_id starts at 0
+ * while number of answers is an integer and
+ * starts at 1.
+ */
+ if (i + 1 == r_res->header.ancount) {
+ cause = RSLV_RESP_CNAME_ERROR;
+ goto return_error;
+ }
+
+ offset = 0;
+ len = resolv_read_name(resp, bufend, reader, tmpname, DNS_MAX_NAME_SIZE, &offset, 0);
+ if (len == 0)
+ goto invalid_resp;
+
+ memcpy(answer_record->data.target, tmpname, len);
+ answer_record->data.target[len] = 0;
+ key = XXH32(tmpname, len, answer_record->type);
+ previous_dname = answer_record->data.target;
+ break;
+
+
+ case DNS_RTYPE_SRV:
+ /* Answer must contain :
+ * - 2 bytes for the priority
+ * - 2 bytes for the weight
+ * - 2 bytes for the port
+ * - the target hostname
+ */
+ if (answer_record->data_len <= 6)
+ goto invalid_resp;
+
+ answer_record->priority = read_n16(reader);
+ reader += sizeof(uint16_t);
+ answer_record->weight = read_n16(reader);
+ reader += sizeof(uint16_t);
+ answer_record->port = read_n16(reader);
+ reader += sizeof(uint16_t);
+ offset = 0;
+ len = resolv_read_name(resp, bufend, reader, tmpname, DNS_MAX_NAME_SIZE, &offset, 0);
+ if (len == 0)
+ goto invalid_resp;
+
+ answer_record->data_len = len;
+ memcpy(answer_record->data.target, tmpname, len);
+ answer_record->data.target[len] = 0;
+ key = XXH32(tmpname, len, answer_record->type);
+ if (answer_record->ar_item != NULL) {
+ pool_free(resolv_answer_item_pool, answer_record->ar_item);
+ answer_record->ar_item = NULL;
+ }
+ break;
+
+ case DNS_RTYPE_AAAA:
+ /* ipv6 is stored on 16 bytes */
+ if (answer_record->data_len != 16)
+ goto invalid_resp;
+
+ answer_record->data.in6.sin6_family = AF_INET6;
+ memcpy(&answer_record->data.in6.sin6_addr, reader, answer_record->data_len);
+ key = XXH32(reader, answer_record->data_len, answer_record->type);
+ break;
+
+ } /* switch (record type) */
+
+ /* Increment the counter for number of records saved into our
+ * local response */
+ nb_saved_records++;
+
+ /* Move forward answer_record->data_len for analyzing next
+ * record in the response */
+ reader += ((answer_record->type == DNS_RTYPE_SRV)
+ ? offset
+ : answer_record->data_len);
+
+ /* Lookup to see if we already had this entry */
+ found = 0;
+
+ for (eb32 = eb32_lookup(&r_res->answer_tree, key); eb32 != NULL; eb32 = eb32_next(eb32)) {
+ tmp_record = eb32_entry(eb32, typeof(*tmp_record), link);
+ if (tmp_record->type != answer_record->type)
+ continue;
+
+ switch(tmp_record->type) {
+ case DNS_RTYPE_A:
+ if (!memcmp(&answer_record->data.in4.sin_addr,
+ &tmp_record->data.in4.sin_addr,
+ sizeof(answer_record->data.in4.sin_addr)))
+ found = 1;
+ break;
+
+ case DNS_RTYPE_AAAA:
+ if (!memcmp(&answer_record->data.in6.sin6_addr,
+ &tmp_record->data.in6.sin6_addr,
+ sizeof(answer_record->data.in6.sin6_addr)))
+ found = 1;
+ break;
+
+ case DNS_RTYPE_SRV:
+ if (answer_record->data_len == tmp_record->data_len &&
+ memcmp(answer_record->data.target, tmp_record->data.target, answer_record->data_len) == 0 &&
+ answer_record->port == tmp_record->port) {
+ tmp_record->weight = answer_record->weight;
+ found = 1;
+ }
+ break;
+
+ default:
+ break;
+ }
+
+ if (found == 1)
+ break;
+ }
+
+ if (found == 1) {
+ tmp_record->last_seen = now_ms;
+ pool_free(resolv_answer_item_pool, answer_record);
+ answer_record = NULL;
+ }
+ else {
+ answer_record->last_seen = now_ms;
+ answer_record->ar_item = NULL;
+ answer_record->link.key = key;
+ eb32_insert(&r_res->answer_tree, &answer_record->link);
+ answer_record = NULL;
+ }
+ } /* for i 0 to ancount */
+
+ /* Save the number of records we really own */
+ r_res->header.ancount = nb_saved_records;
+
+ /* now parsing additional records for SRV queries only */
+ if (query->type != DNS_RTYPE_SRV)
+ goto skip_parsing_additional_records;
+
+ /* if we find Authority records, just skip them */
+ for (i = 0; i < r_res->header.nscount; i++) {
+ offset = 0;
+ len = resolv_read_name(resp, bufend, reader, tmpname, DNS_MAX_NAME_SIZE,
+ &offset, 0);
+ if (len == 0)
+ continue;
+
+ if (reader + offset + 10 >= bufend)
+ goto invalid_resp;
+
+ reader += offset;
+ /* skip 2 bytes for class */
+ reader += 2;
+ /* skip 2 bytes for type */
+ reader += 2;
+ /* skip 4 bytes for ttl */
+ reader += 4;
+ /* read data len */
+ len = reader[0] * 256 + reader[1];
+ reader += 2;
+
+ if (reader + len >= bufend)
+ goto invalid_resp;
+
+ reader += len;
+ }
+
+ nb_saved_records = 0;
+ for (i = 0; i < r_res->header.arcount; i++) {
+ if (reader >= bufend)
+ goto invalid_resp;
+
+ answer_record = pool_alloc(resolv_answer_item_pool);
+ if (answer_record == NULL)
+ goto invalid_resp;
+ answer_record->last_seen = TICK_ETERNITY;
+ LIST_INIT(&answer_record->attached_servers);
+
+ offset = 0;
+ len = resolv_read_name(resp, bufend, reader, tmpname, DNS_MAX_NAME_SIZE, &offset, 0);
+
+ if (len == 0) {
+ pool_free(resolv_answer_item_pool, answer_record);
+ answer_record = NULL;
+ continue;
+ }
+
+ memcpy(answer_record->name, tmpname, len);
+ answer_record->name[len] = 0;
+
+ reader += offset;
+ if (reader >= bufend)
+ goto invalid_resp;
+
+ /* 2 bytes for record type (A, AAAA, CNAME, etc...) */
+ if (reader + 2 > bufend)
+ goto invalid_resp;
+
+ answer_record->type = reader[0] * 256 + reader[1];
+ reader += 2;
+
+ /* 2 bytes for class (2) */
+ if (reader + 2 > bufend)
+ goto invalid_resp;
+
+ answer_record->class = reader[0] * 256 + reader[1];
+ reader += 2;
+
+ /* 4 bytes for ttl (4) */
+ if (reader + 4 > bufend)
+ goto invalid_resp;
+
+ answer_record->ttl = reader[0] * 16777216 + reader[1] * 65536
+ + reader[2] * 256 + reader[3];
+ reader += 4;
+
+ /* Now reading data len */
+ if (reader + 2 > bufend)
+ goto invalid_resp;
+
+ answer_record->data_len = reader[0] * 256 + reader[1];
+
+ /* Move forward 2 bytes for data len */
+ reader += 2;
+
+ if (reader + answer_record->data_len > bufend)
+ goto invalid_resp;
+
+ /* Analyzing record content */
+ switch (answer_record->type) {
+ case DNS_RTYPE_A:
+ /* ipv4 is stored on 4 bytes */
+ if (answer_record->data_len != 4)
+ goto invalid_resp;
+
+ answer_record->data.in4.sin_family = AF_INET;
+ memcpy(&answer_record->data.in4.sin_addr, reader, answer_record->data_len);
+ break;
+
+ case DNS_RTYPE_AAAA:
+ /* ipv6 is stored on 16 bytes */
+ if (answer_record->data_len != 16)
+ goto invalid_resp;
+
+ answer_record->data.in6.sin6_family = AF_INET6;
+ memcpy(&answer_record->data.in6.sin6_addr, reader, answer_record->data_len);
+ break;
+
+ default:
+ pool_free(resolv_answer_item_pool, answer_record);
+ answer_record = NULL;
+ continue;
+
+ } /* switch (record type) */
+
+ /* Increment the counter for number of records saved into our
+ * local response */
+ nb_saved_records++;
+
+ /* Move forward answer_record->data_len for analyzing next
+ * record in the response */
+ reader += answer_record->data_len;
+
+ /* Lookup to see if we already had this entry */
+ found = 0;
+
+ for (eb32 = eb32_first(&r_res->answer_tree); eb32 != NULL; eb32 = eb32_next(eb32)) {
+ struct resolv_answer_item *ar_item;
+
+ tmp_record = eb32_entry(eb32, typeof(*tmp_record), link);
+ if (tmp_record->type != DNS_RTYPE_SRV || !tmp_record->ar_item)
+ continue;
+
+ ar_item = tmp_record->ar_item;
+ if (ar_item->type != answer_record->type || ar_item->last_seen == now_ms ||
+ len != tmp_record->data_len ||
+ memcmp(answer_record->name, tmp_record->data.target, tmp_record->data_len) != 0)
+ continue;
+
+ switch(ar_item->type) {
+ case DNS_RTYPE_A:
+ if (!memcmp(&answer_record->data.in4.sin_addr,
+ &ar_item->data.in4.sin_addr,
+ sizeof(answer_record->data.in4.sin_addr)))
+ found = 1;
+ break;
+
+ case DNS_RTYPE_AAAA:
+ if (!memcmp(&answer_record->data.in6.sin6_addr,
+ &ar_item->data.in6.sin6_addr,
+ sizeof(answer_record->data.in6.sin6_addr)))
+ found = 1;
+ break;
+
+ default:
+ break;
+ }
+
+ if (found == 1)
+ break;
+ }
+
+ if (found == 1) {
+ tmp_record->ar_item->last_seen = now_ms;
+ pool_free(resolv_answer_item_pool, answer_record);
+ answer_record = NULL;
+ }
+ else {
+ answer_record->last_seen = now_ms;
+ answer_record->ar_item = NULL;
+
+ // looking for the SRV record in the response list linked to this additional record
+ for (eb32 = eb32_first(&r_res->answer_tree); eb32 != NULL; eb32 = eb32_next(eb32)) {
+ tmp_record = eb32_entry(eb32, typeof(*tmp_record), link);
+
+ if (tmp_record->type == DNS_RTYPE_SRV &&
+ tmp_record->ar_item == NULL &&
+ memcmp(tmp_record->data.target, answer_record->name, tmp_record->data_len) == 0) {
+ /* Always use the received additional record to refresh info */
+ pool_free(resolv_answer_item_pool, tmp_record->ar_item);
+ tmp_record->ar_item = answer_record;
+ answer_record = NULL;
+ break;
+ }
+ }
+ if (answer_record) {
+ pool_free(resolv_answer_item_pool, answer_record);
+ answer_record = NULL;
+ }
+ }
+ } /* for i 0 to arcount */
+
+ skip_parsing_additional_records:
+
+ /* Save the number of records we really own */
+ r_res->header.arcount = nb_saved_records;
+ resolv_check_response(resolution);
+ return RSLV_RESP_VALID;
+
+ invalid_resp:
+ cause = RSLV_RESP_INVALID;
+
+ return_error:
+ pool_free(resolv_answer_item_pool, answer_record);
+ return cause;
+}
+
+/* Searches dn_name resolution in resp.
+ * If existing IP not found, return the first IP matching family_priority,
+ * otherwise, first ip found
+ * The following tasks are the responsibility of the caller:
+ * - <r_res> contains an error free DNS response
+ * For both cases above, resolv_validate_dns_response is required
+ * returns one of the RSLV_UPD_* code
+ */
+int resolv_get_ip_from_response(struct resolv_response *r_res,
+ struct resolv_options *resolv_opts, void *currentip,
+ short currentip_sin_family,
+ void **newip, short *newip_sin_family,
+ struct server *owner)
+{
+ struct resolv_answer_item *record, *found_record = NULL;
+ struct eb32_node *eb32;
+ int family_priority;
+ int currentip_found;
+ unsigned char *newip4, *newip6;
+ int currentip_sel;
+ int j;
+ int score, max_score;
+ int allowed_duplicated_ip;
+
+ /* srv is linked to an alive ip record */
+ if (owner && LIST_INLIST(&owner->ip_rec_item))
+ return RSLV_UPD_NO;
+
+ family_priority = resolv_opts->family_prio;
+ allowed_duplicated_ip = resolv_opts->accept_duplicate_ip;
+ *newip = newip4 = newip6 = NULL;
+ currentip_found = 0;
+ *newip_sin_family = AF_UNSPEC;
+ max_score = -1;
+
+ /* Select an IP regarding configuration preference.
+ * Top priority is the preferred network ip version,
+ * second priority is the preferred network.
+ * the last priority is the currently used IP,
+ *
+ * For these three priorities, a score is calculated. The
+ * weight are:
+ * 8 - preferred ip version.
+ * 4 - preferred network.
+ * 2 - if the ip in the record is not affected to any other server in the same backend (duplication)
+ * 1 - current ip.
+ * The result with the biggest score is returned.
+ */
+
+ for (eb32 = eb32_first(&r_res->answer_tree); eb32 != NULL; eb32 = eb32_next(eb32)) {
+ void *ip;
+ unsigned char ip_type;
+
+ record = eb32_entry(eb32, typeof(*record), link);
+ if (record->type == DNS_RTYPE_A) {
+ ip_type = AF_INET;
+ ip = &record->data.in4.sin_addr;
+ }
+ else if (record->type == DNS_RTYPE_AAAA) {
+ ip_type = AF_INET6;
+ ip = &record->data.in6.sin6_addr;
+ }
+ else
+ continue;
+ score = 0;
+
+ /* Check for preferred ip protocol. */
+ if (ip_type == family_priority)
+ score += 8;
+
+ /* Check for preferred network. */
+ for (j = 0; j < resolv_opts->pref_net_nb; j++) {
+
+ /* Compare only the same addresses class. */
+ if (resolv_opts->pref_net[j].family != ip_type)
+ continue;
+
+ if ((ip_type == AF_INET &&
+ in_net_ipv4(ip,
+ &resolv_opts->pref_net[j].mask.in4,
+ &resolv_opts->pref_net[j].addr.in4)) ||
+ (ip_type == AF_INET6 &&
+ in_net_ipv6(ip,
+ &resolv_opts->pref_net[j].mask.in6,
+ &resolv_opts->pref_net[j].addr.in6))) {
+ score += 4;
+ break;
+ }
+ }
+
+ /* Check if the IP found in the record is already affected to a
+ * member of a group. If not, the score should be incremented
+ * by 2. */
+ if (owner) {
+ struct server *srv;
+ int already_used = 0;
+
+ list_for_each_entry(srv, &record->attached_servers, ip_rec_item) {
+ if (srv == owner)
+ continue;
+ if (srv->proxy == owner->proxy) {
+ already_used = 1;
+ break;
+ }
+ }
+ if (already_used) {
+ if (!allowed_duplicated_ip) {
+ continue;
+ }
+ }
+ else {
+ score += 2;
+ }
+ } else {
+ score += 2;
+ }
+
+ /* Check for current ip matching. */
+ if (ip_type == currentip_sin_family &&
+ ((currentip_sin_family == AF_INET &&
+ !memcmp(ip, currentip, 4)) ||
+ (currentip_sin_family == AF_INET6 &&
+ !memcmp(ip, currentip, 16)))) {
+ score++;
+ currentip_sel = 1;
+ }
+ else
+ currentip_sel = 0;
+
+ /* Keep the address if the score is better than the previous
+ * score. The maximum score is 15, if this value is reached, we
+ * break the parsing. Implicitly, this score is reached the ip
+ * selected is the current ip. */
+ if (score > max_score) {
+ if (ip_type == AF_INET)
+ newip4 = ip;
+ else
+ newip6 = ip;
+ found_record = record;
+ currentip_found = currentip_sel;
+ if (score == 15) {
+ /* this was not registered on the current record but it matches
+ * let's fix it (it may comes from state file */
+ if (owner)
+ LIST_APPEND(&found_record->attached_servers, &owner->ip_rec_item);
+ return RSLV_UPD_NO;
+ }
+ max_score = score;
+ }
+ } /* list for each record entries */
+
+ /* No IP found in the response */
+ if (!newip4 && !newip6)
+ return RSLV_UPD_NO_IP_FOUND;
+
+ /* Case when the caller looks first for an IPv4 address */
+ if (family_priority == AF_INET) {
+ if (newip4) {
+ *newip = newip4;
+ *newip_sin_family = AF_INET;
+ }
+ else if (newip6) {
+ *newip = newip6;
+ *newip_sin_family = AF_INET6;
+ }
+ }
+ /* Case when the caller looks first for an IPv6 address */
+ else if (family_priority == AF_INET6) {
+ if (newip6) {
+ *newip = newip6;
+ *newip_sin_family = AF_INET6;
+ }
+ else if (newip4) {
+ *newip = newip4;
+ *newip_sin_family = AF_INET;
+ }
+ }
+ /* Case when the caller have no preference (we prefer IPv6) */
+ else if (family_priority == AF_UNSPEC) {
+ if (newip6) {
+ *newip = newip6;
+ *newip_sin_family = AF_INET6;
+ }
+ else if (newip4) {
+ *newip = newip4;
+ *newip_sin_family = AF_INET;
+ }
+ }
+
+ /* the ip of this record was chosen for the server */
+ if (owner && found_record) {
+ LIST_DEL_INIT(&owner->ip_rec_item);
+ LIST_APPEND(&found_record->attached_servers, &owner->ip_rec_item);
+ }
+
+ eb32 = eb32_first(&r_res->answer_tree);
+ if (eb32) {
+ /* Move the first record to the end of the list, for internal
+ * round robin.
+ */
+ eb32_delete(eb32);
+ eb32_insert(&r_res->answer_tree, eb32);
+ }
+
+ return (currentip_found ? RSLV_UPD_NO : RSLV_UPD_SRVIP_NOT_FOUND);
+}
+
+/* Turns a domain name label into a string: 3www7haproxy3org into www.haproxy.org
+ *
+ * <dn> contains the input label of <dn_len> bytes long and does not need to be
+ * null-terminated. <str> must be allocated large enough to contain a full host
+ * name plus the trailing zero, and the allocated size must be passed in
+ * <str_len>.
+ *
+ * In case of error, -1 is returned, otherwise, the number of bytes copied in
+ * <str> (including the terminating null byte).
+ */
+int resolv_dn_label_to_str(const char *dn, int dn_len, char *str, int str_len)
+{
+ char *ptr;
+ int i, sz;
+
+ if (str_len < dn_len)
+ return -1;
+
+ ptr = str;
+ for (i = 0; i < dn_len; ++i) {
+ sz = dn[i];
+ if (i)
+ *ptr++ = '.';
+ /* copy the string at i+1 to lower case */
+ for (; sz > 0; sz--)
+ *(ptr++) = tolower(dn[++i]);
+ }
+ *ptr++ = '\0';
+ return (ptr - str);
+}
+
+/* Turns a string into domain name label: www.haproxy.org into 3www7haproxy3org
+ *
+ * <str> contains the input string that is <str_len> bytes long (trailing zero
+ * not needed). <dn> buffer must be allocated large enough to contain the
+ * encoded string and a trailing zero, so it must be at least str_len+2, and
+ * this allocated buffer size must be passed in <dn_len>.
+ *
+ * In case of error, -1 is returned, otherwise, the number of bytes copied in
+ * <dn> (excluding the terminating null byte).
+ */
+int resolv_str_to_dn_label(const char *str, int str_len, char *dn, int dn_len)
+{
+ int i, offset;
+
+ if (dn_len < str_len + 2)
+ return -1;
+
+ /* First byte of dn will be used to store the length of the first
+ * label */
+ offset = 0;
+ for (i = 0; i < str_len; ++i) {
+ if (str[i] == '.') {
+ /* 2 or more consecutive dots is invalid */
+ if (i == offset)
+ return -1;
+
+ /* ignore trailing dot */
+ if (i + 1 == str_len)
+ break;
+
+ dn[offset] = (i - offset);
+ offset = i+1;
+ continue;
+ }
+ dn[i+1] = tolower(str[i]);
+ }
+ dn[offset] = i - offset;
+ dn[i+1] = '\0';
+ return i+1;
+}
+
+/* Validates host name:
+ * - total size
+ * - each label size individually
+ * returns:
+ * 0 in case of error. If <err> is not NULL, an error message is stored there.
+ * 1 when no error. <err> is left unaffected.
+ */
+int resolv_hostname_validation(const char *string, char **err)
+{
+ int i;
+
+ if (strlen(string) > DNS_MAX_NAME_SIZE) {
+ if (err)
+ *err = DNS_TOO_LONG_FQDN;
+ return 0;
+ }
+
+ while (*string) {
+ i = 0;
+ while (*string && *string != '.' && i < DNS_MAX_LABEL_SIZE) {
+ if (!(*string == '-' || *string == '_' ||
+ (*string >= 'a' && *string <= 'z') ||
+ (*string >= 'A' && *string <= 'Z') ||
+ (*string >= '0' && *string <= '9'))) {
+ if (err)
+ *err = DNS_INVALID_CHARACTER;
+ return 0;
+ }
+ i++;
+ string++;
+ }
+
+ if (!(*string))
+ break;
+
+ if (*string != '.' && i >= DNS_MAX_LABEL_SIZE) {
+ if (err)
+ *err = DNS_LABEL_TOO_LONG;
+ return 0;
+ }
+
+ string++;
+ }
+ return 1;
+}
+
+/* Picks up an available resolution from the different resolution list
+ * associated to a resolvers section, in this order:
+ * 1. check in resolutions.curr for the same hostname and query_type
+ * 2. check in resolutions.wait for the same hostname and query_type
+ * 3. Get a new resolution from resolution pool
+ *
+ * Returns an available resolution, NULL if none found.
+ */
+static struct resolv_resolution *resolv_pick_resolution(struct resolvers *resolvers,
+ char **hostname_dn, int hostname_dn_len,
+ int query_type)
+{
+ struct resolv_resolution *res;
+
+ if (!*hostname_dn)
+ goto from_pool;
+
+ /* Search for same hostname and query type in resolutions.curr */
+ list_for_each_entry(res, &resolvers->resolutions.curr, list) {
+ if (!res->hostname_dn)
+ continue;
+ if ((query_type == res->prefered_query_type) &&
+ hostname_dn_len == res->hostname_dn_len &&
+ memcmp(*hostname_dn, res->hostname_dn, hostname_dn_len) == 0)
+ return res;
+ }
+
+ /* Search for same hostname and query type in resolutions.wait */
+ list_for_each_entry(res, &resolvers->resolutions.wait, list) {
+ if (!res->hostname_dn)
+ continue;
+ if ((query_type == res->prefered_query_type) &&
+ hostname_dn_len == res->hostname_dn_len &&
+ memcmp(*hostname_dn, res->hostname_dn, hostname_dn_len) == 0)
+ return res;
+ }
+
+ from_pool:
+ /* No resolution could be found, so let's allocate a new one */
+ res = pool_zalloc(resolv_resolution_pool);
+ if (res) {
+ res->resolvers = resolvers;
+ res->uuid = resolution_uuid;
+ res->status = RSLV_STATUS_NONE;
+ res->step = RSLV_STEP_NONE;
+ res->last_valid = now_ms;
+
+ LIST_INIT(&res->requesters);
+ res->response.answer_tree = EB_ROOT;
+
+ res->prefered_query_type = query_type;
+ res->query_type = query_type;
+ res->hostname_dn = *hostname_dn;
+ res->hostname_dn_len = hostname_dn_len;
+
+ ++resolution_uuid;
+
+ /* Move the resolution to the resolvers wait queue */
+ LIST_APPEND(&resolvers->resolutions.wait, &res->list);
+ }
+ return res;
+}
+
+/* deletes and frees all answer_items from the resolution's answer_list */
+static void resolv_purge_resolution_answer_records(struct resolv_resolution *resolution)
+{
+ struct eb32_node *eb32, *eb32_back;
+ struct resolv_answer_item *item;
+
+ for (eb32 = eb32_first(&resolution->response.answer_tree);
+ eb32 && (eb32_back = eb32_next(eb32), 1);
+ eb32 = eb32_back) {
+ item = eb32_entry(eb32, typeof(*item), link);
+ eb32_delete(&item->link);
+ pool_free(resolv_answer_item_pool, item->ar_item);
+ pool_free(resolv_answer_item_pool, item);
+ }
+}
+
+/* Releases a resolution from its requester(s) and move it back to the pool */
+static void resolv_free_resolution(struct resolv_resolution *resolution)
+{
+ struct resolv_requester *req, *reqback;
+
+ /* clean up configuration */
+ resolv_reset_resolution(resolution);
+ resolution->hostname_dn = NULL;
+ resolution->hostname_dn_len = 0;
+
+ list_for_each_entry_safe(req, reqback, &resolution->requesters, list) {
+ LIST_DEL_INIT(&req->list);
+ req->resolution = NULL;
+ }
+ resolv_purge_resolution_answer_records(resolution);
+
+ LIST_DEL_INIT(&resolution->list);
+ pool_free(resolv_resolution_pool, resolution);
+}
+
+/* If *<req> is not NULL, returns it, otherwise tries to allocate a requester
+ * and makes it owned by this obj_type, with the proposed callback and error
+ * callback. On success, *req is assigned the allocated requester. Returns
+ * NULL on allocation failure.
+ */
+static struct resolv_requester *
+resolv_get_requester(struct resolv_requester **req, enum obj_type *owner,
+ int (*cb)(struct resolv_requester *, struct dns_counters *),
+ int (*err_cb)(struct resolv_requester *, int))
+{
+ struct resolv_requester *tmp;
+
+ if (*req)
+ return *req;
+
+ tmp = pool_alloc(resolv_requester_pool);
+ if (!tmp)
+ goto end;
+
+ LIST_INIT(&tmp->list);
+ tmp->owner = owner;
+ tmp->resolution = NULL;
+ tmp->requester_cb = cb;
+ tmp->requester_error_cb = err_cb;
+ *req = tmp;
+ end:
+ return tmp;
+}
+
+/* Links a requester (a server or a resolv_srvrq) with a resolution. It returns 0
+ * on success, -1 otherwise.
+ */
+int resolv_link_resolution(void *requester, int requester_type, int requester_locked)
+{
+ struct resolv_resolution *res = NULL;
+ struct resolv_requester *req;
+ struct resolvers *resolvers;
+ struct server *srv = NULL;
+ struct resolv_srvrq *srvrq = NULL;
+ struct stream *stream = NULL;
+ char **hostname_dn;
+ int hostname_dn_len, query_type;
+
+ enter_resolver_code();
+ switch (requester_type) {
+ case OBJ_TYPE_SERVER:
+ srv = (struct server *)requester;
+
+ if (!requester_locked)
+ HA_SPIN_LOCK(SERVER_LOCK, &srv->lock);
+
+ req = resolv_get_requester(&srv->resolv_requester,
+ &srv->obj_type,
+ snr_resolution_cb,
+ snr_resolution_error_cb);
+
+ if (!requester_locked)
+ HA_SPIN_UNLOCK(SERVER_LOCK, &srv->lock);
+
+ if (!req)
+ goto err;
+
+ hostname_dn = &srv->hostname_dn;
+ hostname_dn_len = srv->hostname_dn_len;
+ resolvers = srv->resolvers;
+ query_type = ((srv->resolv_opts.family_prio == AF_INET)
+ ? DNS_RTYPE_A
+ : DNS_RTYPE_AAAA);
+ break;
+
+ case OBJ_TYPE_SRVRQ:
+ srvrq = (struct resolv_srvrq *)requester;
+
+ req = resolv_get_requester(&srvrq->requester,
+ &srvrq->obj_type,
+ snr_resolution_cb,
+ srvrq_resolution_error_cb);
+ if (!req)
+ goto err;
+
+ hostname_dn = &srvrq->hostname_dn;
+ hostname_dn_len = srvrq->hostname_dn_len;
+ resolvers = srvrq->resolvers;
+ query_type = DNS_RTYPE_SRV;
+ break;
+
+ case OBJ_TYPE_STREAM:
+ stream = (struct stream *)requester;
+
+ req = resolv_get_requester(&stream->resolv_ctx.requester,
+ &stream->obj_type,
+ act_resolution_cb,
+ act_resolution_error_cb);
+ if (!req)
+ goto err;
+
+ hostname_dn = &stream->resolv_ctx.hostname_dn;
+ hostname_dn_len = stream->resolv_ctx.hostname_dn_len;
+ resolvers = stream->resolv_ctx.parent->arg.resolv.resolvers;
+ query_type = ((stream->resolv_ctx.parent->arg.resolv.opts->family_prio == AF_INET)
+ ? DNS_RTYPE_A
+ : DNS_RTYPE_AAAA);
+ break;
+ default:
+ goto err;
+ }
+
+ /* Get a resolution from the resolvers' wait queue or pool */
+ if ((res = resolv_pick_resolution(resolvers, hostname_dn, hostname_dn_len, query_type)) == NULL)
+ goto err;
+
+ req->resolution = res;
+
+ LIST_APPEND(&res->requesters, &req->list);
+ leave_resolver_code();
+ return 0;
+
+ err:
+ if (res && LIST_ISEMPTY(&res->requesters))
+ resolv_free_resolution(res);
+ leave_resolver_code();
+ return -1;
+}
+
+/* This function removes all server/srvrq references on answer items. */
+void resolv_detach_from_resolution_answer_items(struct resolv_resolution *res, struct resolv_requester *req)
+{
+ struct eb32_node *eb32, *eb32_back;
+ struct resolv_answer_item *item;
+ struct server *srv, *srvback;
+ struct resolv_srvrq *srvrq;
+
+ enter_resolver_code();
+ if ((srv = objt_server(req->owner)) != NULL) {
+ LIST_DEL_INIT(&srv->ip_rec_item);
+ }
+ else if ((srvrq = objt_resolv_srvrq(req->owner)) != NULL) {
+ for (eb32 = eb32_first(&res->response.answer_tree);
+ eb32 && (eb32_back = eb32_next(eb32), 1);
+ eb32 = eb32_back) {
+ item = eb32_entry(eb32, typeof(*item), link);
+ if (item->type == DNS_RTYPE_SRV) {
+ list_for_each_entry_safe(srv, srvback, &item->attached_servers, srv_rec_item) {
+ if (srv->srvrq == srvrq)
+ resolv_srvrq_cleanup_srv(srv);
+ }
+ }
+ }
+ }
+ leave_resolver_code();
+}
+
+/* Removes a requester from a DNS resolution. It takes takes care of all the
+ * consequences. It also cleans up some parameters from the requester.
+ */
+static void _resolv_unlink_resolution(struct resolv_requester *requester)
+{
+ struct resolv_resolution *res;
+ struct resolv_requester *req;
+
+ /* Nothing to do */
+ if (!requester || !requester->resolution)
+ return;
+ res = requester->resolution;
+
+ /* Clean up the requester */
+ LIST_DEL_INIT(&requester->list);
+ requester->resolution = NULL;
+
+ /* remove ref from the resolution answer item list to the requester */
+ resolv_detach_from_resolution_answer_items(res, requester);
+
+ /* We need to find another requester linked on this resolution */
+ if (!LIST_ISEMPTY(&res->requesters))
+ req = LIST_NEXT(&res->requesters, struct resolv_requester *, list);
+ else {
+ abort_resolution(res);
+ return;
+ }
+
+ /* Move hostname_dn related pointers to the next requester */
+ switch (obj_type(req->owner)) {
+ case OBJ_TYPE_SERVER:
+ res->hostname_dn = __objt_server(req->owner)->hostname_dn;
+ res->hostname_dn_len = __objt_server(req->owner)->hostname_dn_len;
+ break;
+ case OBJ_TYPE_SRVRQ:
+ res->hostname_dn = __objt_resolv_srvrq(req->owner)->hostname_dn;
+ res->hostname_dn_len = __objt_resolv_srvrq(req->owner)->hostname_dn_len;
+ break;
+ case OBJ_TYPE_STREAM:
+ res->hostname_dn = __objt_stream(req->owner)->resolv_ctx.hostname_dn;
+ res->hostname_dn_len = __objt_stream(req->owner)->resolv_ctx.hostname_dn_len;
+ break;
+ default:
+ res->hostname_dn = NULL;
+ res->hostname_dn_len = 0;
+ break;
+ }
+}
+
+/* The public version of the function above that deals with the death row. */
+void resolv_unlink_resolution(struct resolv_requester *requester)
+{
+ enter_resolver_code();
+ _resolv_unlink_resolution(requester);
+ leave_resolver_code();
+}
+
+/* Called when a network IO is generated on a name server socket for an incoming
+ * packet. It performs the following actions:
+ * - check if the packet requires processing (not outdated resolution)
+ * - ensure the DNS packet received is valid and call requester's callback
+ * - call requester's error callback if invalid response
+ * - check the dn_name in the packet against the one sent
+ */
+static int resolv_process_responses(struct dns_nameserver *ns)
+{
+ struct dns_counters *tmpcounters;
+ struct resolvers *resolvers;
+ struct resolv_resolution *res;
+ unsigned char buf[DNS_MAX_UDP_MESSAGE + 1];
+ unsigned char *bufend;
+ int buflen, dns_resp;
+ int max_answer_records;
+ unsigned short query_id;
+ struct eb32_node *eb;
+ struct resolv_requester *req;
+ int keep_answer_items;
+
+ resolvers = ns->parent;
+ enter_resolver_code();
+ HA_SPIN_LOCK(DNS_LOCK, &resolvers->lock);
+
+ /* process all pending input messages */
+ while (1) {
+ /* read message received */
+ memset(buf, '\0', resolvers->accepted_payload_size + 1);
+ if ((buflen = dns_recv_nameserver(ns, (void *)buf, sizeof(buf))) <= 0) {
+ break;
+ }
+
+ /* message too big */
+ if (buflen > resolvers->accepted_payload_size) {
+ ns->counters->app.resolver.too_big++;
+ continue;
+ }
+
+ /* initializing variables */
+ bufend = buf + buflen; /* pointer to mark the end of the buffer */
+
+ /* read the query id from the packet (16 bits) */
+ if (buf + 2 > bufend) {
+ ns->counters->app.resolver.invalid++;
+ continue;
+ }
+ query_id = resolv_response_get_query_id(buf);
+
+ /* search the query_id in the pending resolution tree */
+ eb = eb32_lookup(&resolvers->query_ids, query_id);
+ if (eb == NULL) {
+ /* unknown query id means an outdated response and can be safely ignored */
+ ns->counters->app.resolver.outdated++;
+ continue;
+ }
+
+ /* known query id means a resolution in progress */
+ res = eb32_entry(eb, struct resolv_resolution, qid);
+ /* number of responses received */
+ res->nb_responses++;
+
+ max_answer_records = (resolvers->accepted_payload_size - DNS_HEADER_SIZE) / DNS_MIN_RECORD_SIZE;
+ dns_resp = resolv_validate_dns_response(buf, bufend, res, max_answer_records);
+
+ switch (dns_resp) {
+ case RSLV_RESP_VALID:
+ break;
+
+ case RSLV_RESP_INVALID:
+ case RSLV_RESP_QUERY_COUNT_ERROR:
+ case RSLV_RESP_WRONG_NAME:
+ res->status = RSLV_STATUS_INVALID;
+ ns->counters->app.resolver.invalid++;
+ break;
+
+ case RSLV_RESP_NX_DOMAIN:
+ res->status = RSLV_STATUS_NX;
+ ns->counters->app.resolver.nx++;
+ break;
+
+ case RSLV_RESP_REFUSED:
+ res->status = RSLV_STATUS_REFUSED;
+ ns->counters->app.resolver.refused++;
+ break;
+
+ case RSLV_RESP_ANCOUNT_ZERO:
+ res->status = RSLV_STATUS_OTHER;
+ ns->counters->app.resolver.any_err++;
+ break;
+
+ case RSLV_RESP_CNAME_ERROR:
+ res->status = RSLV_STATUS_OTHER;
+ ns->counters->app.resolver.cname_error++;
+ break;
+
+ case RSLV_RESP_TRUNCATED:
+ res->status = RSLV_STATUS_OTHER;
+ ns->counters->app.resolver.truncated++;
+ break;
+
+ case RSLV_RESP_NO_EXPECTED_RECORD:
+ case RSLV_RESP_ERROR:
+ case RSLV_RESP_INTERNAL:
+ res->status = RSLV_STATUS_OTHER;
+ ns->counters->app.resolver.other++;
+ break;
+ }
+
+ /* Wait all nameservers response to handle errors */
+ if (dns_resp != RSLV_RESP_VALID && res->nb_responses < res->nb_queries)
+ continue;
+
+ /* Process error codes */
+ if (dns_resp != RSLV_RESP_VALID) {
+ if (res->prefered_query_type != res->query_type) {
+ /* The fallback on the query type was already performed,
+ * so check the try counter. If it falls to 0, we can
+ * report an error. Else, wait the next attempt. */
+ if (!res->try)
+ goto report_res_error;
+ }
+ else {
+ /* Fallback from A to AAAA or the opposite and re-send
+ * the resolution immediately. try counter is not
+ * decremented. */
+ if (res->prefered_query_type == DNS_RTYPE_A) {
+ res->query_type = DNS_RTYPE_AAAA;
+ resolv_send_query(res);
+ }
+ else if (res->prefered_query_type == DNS_RTYPE_AAAA) {
+ res->query_type = DNS_RTYPE_A;
+ resolv_send_query(res);
+ }
+ }
+ continue;
+ }
+
+ /* So the resolution succeeded */
+ res->status = RSLV_STATUS_VALID;
+ res->last_valid = now_ms;
+ ns->counters->app.resolver.valid++;
+ goto report_res_success;
+
+ report_res_error:
+ keep_answer_items = 0;
+ list_for_each_entry(req, &res->requesters, list)
+ keep_answer_items |= req->requester_error_cb(req, dns_resp);
+ if (!keep_answer_items)
+ resolv_purge_resolution_answer_records(res);
+ resolv_reset_resolution(res);
+ LIST_DEL_INIT(&res->list);
+ LIST_APPEND(&resolvers->resolutions.wait, &res->list);
+ continue;
+
+ report_res_success:
+ /* Only the 1rst requester s managed by the server, others are
+ * from the cache */
+ tmpcounters = ns->counters;
+ list_for_each_entry(req, &res->requesters, list) {
+ struct server *s = objt_server(req->owner);
+
+ if (s)
+ HA_SPIN_LOCK(SERVER_LOCK, &s->lock);
+ req->requester_cb(req, tmpcounters);
+ if (s)
+ HA_SPIN_UNLOCK(SERVER_LOCK, &s->lock);
+ tmpcounters = NULL;
+ }
+
+ resolv_reset_resolution(res);
+ LIST_DEL_INIT(&res->list);
+ LIST_APPEND(&resolvers->resolutions.wait, &res->list);
+ continue;
+ }
+ resolv_update_resolvers_timeout(resolvers);
+ HA_SPIN_UNLOCK(DNS_LOCK, &resolvers->lock);
+ leave_resolver_code();
+ return buflen;
+}
+
+/* Processes DNS resolution. First, it checks the active list to detect expired
+ * resolutions and retry them if possible. Else a timeout is reported. Then, it
+ * checks the wait list to trigger new resolutions.
+ */
+struct task *process_resolvers(struct task *t, void *context, unsigned int state)
+{
+ struct resolvers *resolvers = context;
+ struct resolv_resolution *res, *resback;
+ int exp;
+
+ enter_resolver_code();
+ HA_SPIN_LOCK(DNS_LOCK, &resolvers->lock);
+
+ /* Handle all expired resolutions from the active list. Elements that
+ * need to be removed will in fact be moved to the death_row. Other
+ * ones will be handled normally.
+ */
+
+ res = LIST_NEXT(&resolvers->resolutions.curr, struct resolv_resolution *, list);
+ while (&res->list != &resolvers->resolutions.curr) {
+ resback = LIST_NEXT(&res->list, struct resolv_resolution *, list);
+
+ if (LIST_ISEMPTY(&res->requesters)) {
+ abort_resolution(res);
+ res = resback;
+ continue;
+ }
+
+ /* When we find the first resolution in the future, then we can
+ * stop here */
+ exp = tick_add(res->last_query, resolvers->timeout.retry);
+ if (!tick_is_expired(exp, now_ms))
+ break;
+
+ /* If current resolution has been tried too many times and
+ * finishes in timeout we update its status and remove it from
+ * the list */
+ if (!res->try) {
+ struct resolv_requester *req;
+ int keep_answer_items = 0;
+
+ /* Notify the result to the requesters */
+ if (!res->nb_responses)
+ res->status = RSLV_STATUS_TIMEOUT;
+ list_for_each_entry(req, &res->requesters, list)
+ keep_answer_items |= req->requester_error_cb(req, res->status);
+ if (!keep_answer_items)
+ resolv_purge_resolution_answer_records(res);
+
+ /* Clean up resolution info and remove it from the
+ * current list */
+ resolv_reset_resolution(res);
+
+ /* subsequent entries might have been deleted here */
+ resback = LIST_NEXT(&res->list, struct resolv_resolution *, list);
+ LIST_DEL_INIT(&res->list);
+ LIST_APPEND(&resolvers->resolutions.wait, &res->list);
+ res = resback;
+ }
+ else {
+ /* Otherwise resend the DNS query and requeue the resolution */
+ if (!res->nb_responses || res->prefered_query_type != res->query_type) {
+ /* No response received (a real timeout) or fallback already done */
+ res->query_type = res->prefered_query_type;
+ res->try--;
+ }
+ else {
+ /* Fallback from A to AAAA or the opposite and re-send
+ * the resolution immediately. try counter is not
+ * decremented. */
+ if (res->prefered_query_type == DNS_RTYPE_A)
+ res->query_type = DNS_RTYPE_AAAA;
+ else if (res->prefered_query_type == DNS_RTYPE_AAAA)
+ res->query_type = DNS_RTYPE_A;
+ else
+ res->try--;
+ }
+ resolv_send_query(res);
+ resback = LIST_NEXT(&res->list, struct resolv_resolution *, list);
+ res = resback;
+ }
+ }
+
+ /* Handle all resolutions in the wait list */
+ list_for_each_entry_safe(res, resback, &resolvers->resolutions.wait, list) {
+
+ if (unlikely(stopping)) {
+ /* If haproxy is stopping, check if the resolution to know if it must be run or not.
+ * If at least a requester is a stream (because of a do-resolv action) or if there
+ * is a requester attached to a running proxy, the resolution is performed.
+ * Otherwise, it is skipped for now.
+ */
+ struct resolv_requester *req;
+ int must_run = 0;
+
+ list_for_each_entry(req, &res->requesters, list) {
+ struct proxy *px = NULL;
+
+ switch (obj_type(req->owner)) {
+ case OBJ_TYPE_SERVER:
+ px = __objt_server(req->owner)->proxy;
+ break;
+ case OBJ_TYPE_SRVRQ:
+ px = __objt_resolv_srvrq(req->owner)->proxy;
+ break;
+ case OBJ_TYPE_STREAM:
+ /* Always perform the resolution */
+ must_run = 1;
+ break;
+ default:
+ break;
+ }
+ /* Perform the resolution if the proxy is not stopped or disabled */
+ if (px && !(px->flags & (PR_FL_DISABLED|PR_FL_STOPPED)))
+ must_run = 1;
+
+ if (must_run)
+ break;
+ }
+
+ if (!must_run) {
+ /* Skip the reolsution. reset it and wait for the next wakeup */
+ resolv_reset_resolution(res);
+ continue;
+ }
+ }
+
+ if (LIST_ISEMPTY(&res->requesters)) {
+ abort_resolution(res);
+ continue;
+ }
+
+ exp = tick_add(res->last_resolution, resolv_resolution_timeout(res));
+ if (tick_isset(res->last_resolution) && !tick_is_expired(exp, now_ms))
+ continue;
+
+ if (resolv_run_resolution(res) != 1) {
+ res->last_resolution = now_ms;
+ LIST_DEL_INIT(&res->list);
+ LIST_APPEND(&resolvers->resolutions.wait, &res->list);
+ }
+ }
+
+ resolv_update_resolvers_timeout(resolvers);
+ HA_SPIN_UNLOCK(DNS_LOCK, &resolvers->lock);
+
+ if (unlikely(stopping)) {
+ struct dns_nameserver *ns;
+
+ if (LIST_ISEMPTY(&resolvers->resolutions.curr))
+ t->expire = TICK_ETERNITY;
+
+ list_for_each_entry(ns, &resolvers->nameservers, list) {
+ if (ns->stream)
+ task_wakeup(ns->stream->task_idle, TASK_WOKEN_MSG);
+ }
+ }
+
+ /* now we can purge all queued deletions */
+ leave_resolver_code();
+ return t;
+}
+
+
+/* destroy a resolvers */
+static void resolvers_destroy(struct resolvers *resolvers)
+{
+ struct dns_nameserver *ns, *nsback;
+ struct resolv_resolution *res, *resback;
+ struct resolv_requester *req, *reqback;
+
+ list_for_each_entry_safe(ns, nsback, &resolvers->nameservers, list) {
+ free(ns->id);
+ free((char *)ns->conf.file);
+ if (ns->dgram) {
+ if (ns->dgram->conn.t.sock.fd != -1) {
+ fd_delete(ns->dgram->conn.t.sock.fd);
+ close(ns->dgram->conn.t.sock.fd);
+ }
+ ring_free(ns->dgram->ring_req);
+ free(ns->dgram);
+ }
+ if (ns->stream) {
+ ring_free(ns->stream->ring_req);
+ task_destroy(ns->stream->task_req);
+ task_destroy(ns->stream->task_rsp);
+ free(ns->stream);
+ }
+ LIST_DEL_INIT(&ns->list);
+ EXTRA_COUNTERS_FREE(ns->extra_counters);
+ free(ns);
+ }
+
+ list_for_each_entry_safe(res, resback, &resolvers->resolutions.curr, list) {
+ list_for_each_entry_safe(req, reqback, &res->requesters, list) {
+ LIST_DEL_INIT(&req->list);
+ pool_free(resolv_requester_pool, req);
+ }
+ resolv_free_resolution(res);
+ }
+
+ list_for_each_entry_safe(res, resback, &resolvers->resolutions.wait, list) {
+ list_for_each_entry_safe(req, reqback, &res->requesters, list) {
+ LIST_DEL_INIT(&req->list);
+ pool_free(resolv_requester_pool, req);
+ }
+ resolv_free_resolution(res);
+ }
+
+ free_proxy(resolvers->px);
+ free(resolvers->id);
+ free((char *)resolvers->conf.file);
+ task_destroy(resolvers->t);
+ LIST_DEL_INIT(&resolvers->list);
+ free(resolvers);
+}
+
+/* Release memory allocated by DNS */
+static void resolvers_deinit(void)
+{
+ struct resolvers *resolvers, *resolversback;
+ struct resolv_srvrq *srvrq, *srvrqback;
+
+ list_for_each_entry_safe(resolvers, resolversback, &sec_resolvers, list) {
+ resolvers_destroy(resolvers);
+ }
+
+ list_for_each_entry_safe(srvrq, srvrqback, &resolv_srvrq_list, list) {
+ free(srvrq->name);
+ free(srvrq->hostname_dn);
+ LIST_DEL_INIT(&srvrq->list);
+ free(srvrq);
+ }
+}
+
+/* Finalizes the DNS configuration by allocating required resources and checking
+ * live parameters.
+ * Returns 0 on success, 1 on error.
+ */
+static int resolvers_finalize_config(void)
+{
+ struct resolvers *resolvers;
+ struct proxy *px;
+ int err_code = 0;
+
+ enter_resolver_code();
+
+ /* allocate pool of resolution per resolvers */
+ list_for_each_entry(resolvers, &sec_resolvers, list) {
+ struct dns_nameserver *ns;
+ struct task *t;
+
+ /* Check if we can create the socket with nameservers info */
+ list_for_each_entry(ns, &resolvers->nameservers, list) {
+ int fd;
+
+ if (ns->dgram) {
+ /* Check nameserver info */
+ if ((fd = socket(ns->dgram->conn.addr.to.ss_family, SOCK_DGRAM, IPPROTO_UDP)) == -1) {
+ if (!resolvers->conf.implicit) { /* emit a warning only if it was configured manually */
+ ha_alert("resolvers '%s': can't create socket for nameserver '%s'.\n",
+ resolvers->id, ns->id);
+ err_code |= (ERR_ALERT|ERR_ABORT);
+ }
+ continue;
+ }
+ if (connect(fd, (struct sockaddr*)&ns->dgram->conn.addr.to, get_addr_len(&ns->dgram->conn.addr.to)) == -1) {
+ if (!resolvers->conf.implicit) { /* emit a warning only if it was configured manually */
+ ha_warning("resolvers '%s': can't connect socket for nameserver '%s'.\n",
+ resolvers->id, ns->id);
+ }
+ close(fd);
+ err_code |= ERR_WARN;
+ continue;
+ }
+ close(fd);
+ }
+ }
+
+ /* Create the task associated to the resolvers section */
+ if ((t = task_new_anywhere()) == NULL) {
+ ha_alert("resolvers '%s' : out of memory.\n", resolvers->id);
+ err_code |= (ERR_ALERT|ERR_ABORT);
+ goto err;
+ }
+
+ /* Update task's parameters */
+ t->process = process_resolvers;
+ t->context = resolvers;
+ resolvers->t = t;
+ task_wakeup(t, TASK_WOKEN_INIT);
+ }
+
+ for (px = proxies_list; px; px = px->next) {
+ struct server *srv;
+
+ if (px->flags & PR_FL_DISABLED) {
+ /* must not run and will not work anyway since
+ * nothing in the proxy is initialized.
+ */
+ continue;
+ }
+
+ for (srv = px->srv; srv; srv = srv->next) {
+ struct resolvers *resolvers;
+
+ if (!srv->resolvers_id)
+ continue;
+
+ if ((resolvers = find_resolvers_by_id(srv->resolvers_id)) == NULL) {
+ ha_alert("%s '%s', server '%s': unable to find required resolvers '%s'\n",
+ proxy_type_str(px), px->id, srv->id, srv->resolvers_id);
+ err_code |= (ERR_ALERT|ERR_ABORT);
+ continue;
+ }
+ srv->resolvers = resolvers;
+ srv->srvrq_check = NULL;
+ if (srv->srvrq) {
+ if (!srv->srvrq->resolvers) {
+ srv->srvrq->resolvers = srv->resolvers;
+ if (resolv_link_resolution(srv->srvrq, OBJ_TYPE_SRVRQ, 0) == -1) {
+ ha_alert("%s '%s' : unable to set DNS resolution for server '%s'.\n",
+ proxy_type_str(px), px->id, srv->id);
+ err_code |= (ERR_ALERT|ERR_ABORT);
+ continue;
+ }
+ }
+
+ srv->srvrq_check = task_new_anywhere();
+ if (!srv->srvrq_check) {
+ ha_alert("%s '%s' : unable to create SRVRQ task for server '%s'.\n",
+ proxy_type_str(px), px->id, srv->id);
+ err_code |= (ERR_ALERT|ERR_ABORT);
+ goto err;
+ }
+ srv->srvrq_check->process = resolv_srvrq_expire_task;
+ srv->srvrq_check->context = srv;
+ srv->srvrq_check->expire = TICK_ETERNITY;
+ }
+ else if (resolv_link_resolution(srv, OBJ_TYPE_SERVER, 0) == -1) {
+ ha_alert("%s '%s', unable to set DNS resolution for server '%s'.\n",
+ proxy_type_str(px), px->id, srv->id);
+ err_code |= (ERR_ALERT|ERR_ABORT);
+ continue;
+ }
+
+ srv->flags |= SRV_F_NON_PURGEABLE;
+ }
+ }
+
+ if (err_code & (ERR_ALERT|ERR_ABORT))
+ goto err;
+
+ leave_resolver_code();
+ return 0;
+ err:
+ leave_resolver_code();
+ resolvers_deinit();
+ return 1;
+
+}
+
+static int stats_dump_resolv_to_buffer(struct stconn *sc,
+ struct dns_nameserver *ns,
+ struct field *stats, size_t stats_count,
+ struct list *stat_modules)
+{
+ struct appctx *appctx = __sc_appctx(sc);
+ struct stats_module *mod;
+ size_t idx = 0;
+
+ memset(stats, 0, sizeof(struct field) * stats_count);
+
+ list_for_each_entry(mod, stat_modules, list) {
+ struct counters_node *counters = EXTRA_COUNTERS_GET(ns->extra_counters, mod);
+
+ mod->fill_stats(counters, stats + idx);
+ idx += mod->stats_count;
+ }
+
+ if (!stats_dump_one_line(stats, idx, appctx))
+ return 0;
+
+ if (!stats_putchk(appctx, NULL))
+ goto full;
+
+ return 1;
+
+ full:
+ return 0;
+}
+
+/* Uses <appctx.ctx.stats.obj1> as a pointer to the current resolver and <obj2>
+ * as a pointer to the current nameserver.
+ */
+int stats_dump_resolvers(struct stconn *sc,
+ struct field *stats, size_t stats_count,
+ struct list *stat_modules)
+{
+ struct appctx *appctx = __sc_appctx(sc);
+ struct show_stat_ctx *ctx = appctx->svcctx;
+ struct channel *rep = sc_ic(sc);
+ struct resolvers *resolver = ctx->obj1;
+ struct dns_nameserver *ns = ctx->obj2;
+
+ if (!resolver)
+ resolver = LIST_NEXT(&sec_resolvers, struct resolvers *, list);
+
+ /* dump resolvers */
+ list_for_each_entry_from(resolver, &sec_resolvers, list) {
+ ctx->obj1 = resolver;
+
+ ns = ctx->obj2 ?
+ ctx->obj2 :
+ LIST_NEXT(&resolver->nameservers, struct dns_nameserver *, list);
+
+ list_for_each_entry_from(ns, &resolver->nameservers, list) {
+ ctx->obj2 = ns;
+
+ if (buffer_almost_full(&rep->buf)) {
+ sc_need_room(sc, b_size(&rep->buf) / 2);
+ goto full;
+ }
+
+ if (!stats_dump_resolv_to_buffer(sc, ns,
+ stats, stats_count,
+ stat_modules)) {
+ return 0;
+ }
+ }
+
+ ctx->obj2 = NULL;
+ }
+
+ return 1;
+
+ full:
+ return 0;
+}
+
+void resolv_stats_clear_counters(int clrall, struct list *stat_modules)
+{
+ struct resolvers *resolvers;
+ struct dns_nameserver *ns;
+ struct stats_module *mod;
+ void *counters;
+
+ list_for_each_entry(mod, stat_modules, list) {
+ if (!mod->clearable && !clrall)
+ continue;
+
+ list_for_each_entry(resolvers, &sec_resolvers, list) {
+ list_for_each_entry(ns, &resolvers->nameservers, list) {
+ counters = EXTRA_COUNTERS_GET(ns->extra_counters, mod);
+ memcpy(counters, mod->counters, mod->counters_size);
+ }
+ }
+ }
+
+}
+
+int resolv_allocate_counters(struct list *stat_modules)
+{
+ struct stats_module *mod;
+ struct resolvers *resolvers;
+ struct dns_nameserver *ns;
+
+ list_for_each_entry(resolvers, &sec_resolvers, list) {
+ list_for_each_entry(ns, &resolvers->nameservers, list) {
+ EXTRA_COUNTERS_REGISTER(&ns->extra_counters, COUNTERS_RSLV,
+ alloc_failed);
+
+ list_for_each_entry(mod, stat_modules, list) {
+ EXTRA_COUNTERS_ADD(mod,
+ ns->extra_counters,
+ mod->counters,
+ mod->counters_size);
+ }
+
+ EXTRA_COUNTERS_ALLOC(ns->extra_counters, alloc_failed);
+
+ list_for_each_entry(mod, stat_modules, list) {
+ memcpy(ns->extra_counters->data + mod->counters_off[ns->extra_counters->type],
+ mod->counters, mod->counters_size);
+
+ /* Store the ns counters pointer */
+ if (strcmp(mod->name, "resolvers") == 0) {
+ ns->counters = (struct dns_counters *)ns->extra_counters->data + mod->counters_off[COUNTERS_RSLV];
+ ns->counters->id = ns->id;
+ ns->counters->pid = resolvers->id;
+ }
+ }
+ }
+ }
+
+ return 1;
+
+alloc_failed:
+ return 0;
+}
+
+/* if an arg is found, it sets the optional resolvers section pointer into a
+ * show_resolvers_ctx struct pointed to by svcctx, or NULL when dumping all.
+ */
+static int cli_parse_stat_resolvers(char **args, char *payload, struct appctx *appctx, void *private)
+{
+ struct show_resolvers_ctx *ctx = applet_reserve_svcctx(appctx, sizeof(*ctx));
+ struct resolvers *presolvers;
+
+ if (*args[2]) {
+ list_for_each_entry(presolvers, &sec_resolvers, list) {
+ if (strcmp(presolvers->id, args[2]) == 0) {
+ ctx->forced_section = presolvers;
+ break;
+ }
+ }
+ if (ctx->forced_section == NULL)
+ return cli_err(appctx, "Can't find that resolvers section\n");
+ }
+ return 0;
+}
+
+/* Dumps counters from all resolvers section and associated name servers. It
+ * returns 0 if the output buffer is full and it needs to be called again,
+ * otherwise non-zero. It may limit itself to the resolver pointed to by the
+ * <resolvers> field of struct show_resolvers_ctx pointed to by <svcctx> if
+ * it's not null.
+ */
+static int cli_io_handler_dump_resolvers_to_buffer(struct appctx *appctx)
+{
+ struct show_resolvers_ctx *ctx = appctx->svcctx;
+ struct resolvers *resolvers = ctx->resolvers;
+ struct dns_nameserver *ns;
+
+ chunk_reset(&trash);
+
+ if (LIST_ISEMPTY(&sec_resolvers)) {
+ if (applet_putstr(appctx, "No resolvers found\n") == -1)
+ goto full;
+ }
+ else {
+ if (!resolvers)
+ resolvers = LIST_ELEM(sec_resolvers.n, typeof(resolvers), list);
+
+ list_for_each_entry_from(resolvers, &sec_resolvers, list) {
+ if (ctx->forced_section != NULL && ctx->forced_section != resolvers)
+ continue;
+
+ ctx->resolvers = resolvers;
+ ns = ctx->ns;
+
+ if (!ns) {
+ chunk_printf(&trash, "Resolvers section %s\n", resolvers->id);
+ if (applet_putchk(appctx, &trash) == -1)
+ goto full;
+
+ ns = LIST_ELEM(resolvers->nameservers.n, typeof(ns), list);
+ ctx->ns = ns;
+ }
+
+ list_for_each_entry_from(ns, &resolvers->nameservers, list) {
+ chunk_reset(&trash);
+ chunk_appendf(&trash, " nameserver %s:\n", ns->id);
+ chunk_appendf(&trash, " sent: %lld\n", ns->counters->sent);
+ chunk_appendf(&trash, " snd_error: %lld\n", ns->counters->snd_error);
+ chunk_appendf(&trash, " valid: %lld\n", ns->counters->app.resolver.valid);
+ chunk_appendf(&trash, " update: %lld\n", ns->counters->app.resolver.update);
+ chunk_appendf(&trash, " cname: %lld\n", ns->counters->app.resolver.cname);
+ chunk_appendf(&trash, " cname_error: %lld\n", ns->counters->app.resolver.cname_error);
+ chunk_appendf(&trash, " any_err: %lld\n", ns->counters->app.resolver.any_err);
+ chunk_appendf(&trash, " nx: %lld\n", ns->counters->app.resolver.nx);
+ chunk_appendf(&trash, " timeout: %lld\n", ns->counters->app.resolver.timeout);
+ chunk_appendf(&trash, " refused: %lld\n", ns->counters->app.resolver.refused);
+ chunk_appendf(&trash, " other: %lld\n", ns->counters->app.resolver.other);
+ chunk_appendf(&trash, " invalid: %lld\n", ns->counters->app.resolver.invalid);
+ chunk_appendf(&trash, " too_big: %lld\n", ns->counters->app.resolver.too_big);
+ chunk_appendf(&trash, " truncated: %lld\n", ns->counters->app.resolver.truncated);
+ chunk_appendf(&trash, " outdated: %lld\n", ns->counters->app.resolver.outdated);
+ if (applet_putchk(appctx, &trash) == -1)
+ goto full;
+ ctx->ns = ns;
+ }
+
+ ctx->ns = NULL;
+
+ /* was this the only section to dump ? */
+ if (ctx->forced_section)
+ break;
+ }
+ }
+
+ /* done! */
+ return 1;
+ full:
+ /* the output buffer is full, retry later */
+ return 0;
+}
+
+/* register cli keywords */
+static struct cli_kw_list cli_kws = {{ }, {
+ { { "show", "resolvers", NULL }, "show resolvers [id] : dumps counters from all resolvers section and associated name servers",
+ cli_parse_stat_resolvers, cli_io_handler_dump_resolvers_to_buffer },
+ {{},}
+ }
+};
+
+INITCALL1(STG_REGISTER, cli_register_kw, &cli_kws);
+
+/*
+ * Prepare <rule> for hostname resolution.
+ * Returns -1 in case of any allocation failure, 0 if not.
+ * On error, a global failure counter is also incremented.
+ */
+static int action_prepare_for_resolution(struct stream *stream, const char *hostname, int hostname_len)
+{
+ char *hostname_dn;
+ int hostname_dn_len;
+ struct buffer *tmp = get_trash_chunk();
+
+ if (!hostname)
+ return 0;
+
+ hostname_dn = tmp->area;
+ hostname_dn_len = resolv_str_to_dn_label(hostname, hostname_len,
+ hostname_dn, tmp->size);
+ if (hostname_dn_len == -1)
+ goto err;
+
+
+ stream->resolv_ctx.hostname_dn = strdup(hostname_dn);
+ stream->resolv_ctx.hostname_dn_len = hostname_dn_len;
+ if (!stream->resolv_ctx.hostname_dn)
+ goto err;
+
+ return 0;
+
+ err:
+ ha_free(&stream->resolv_ctx.hostname_dn);
+ resolv_failed_resolutions += 1;
+ return -1;
+}
+
+
+/*
+ * Execute the "do-resolution" action. May be called from {tcp,http}request.
+ */
+enum act_return resolv_action_do_resolve(struct act_rule *rule, struct proxy *px,
+ struct session *sess, struct stream *s, int flags)
+{
+ struct resolv_resolution *resolution;
+ struct sample *smp;
+ struct resolv_requester *req;
+ struct resolvers *resolvers;
+ struct resolv_resolution *res;
+ int exp, locked = 0;
+ enum act_return ret = ACT_RET_CONT;
+
+ resolvers = rule->arg.resolv.resolvers;
+
+ enter_resolver_code();
+
+ /* we have a response to our DNS resolution */
+ use_cache:
+ if (s->resolv_ctx.requester && s->resolv_ctx.requester->resolution != NULL) {
+ resolution = s->resolv_ctx.requester->resolution;
+ if (!locked) {
+ HA_SPIN_LOCK(DNS_LOCK, &resolvers->lock);
+ locked = 1;
+ }
+
+ if (resolution->step == RSLV_STEP_RUNNING)
+ goto yield;
+ if (resolution->step == RSLV_STEP_NONE) {
+ /* We update the variable only if we have a valid
+ * response. If the response was not received yet, we
+ * must yield.
+ */
+ if (resolution->status == RSLV_STATUS_NONE)
+ goto yield;
+ if (resolution->status == RSLV_STATUS_VALID) {
+ struct sample smp;
+ short ip_sin_family = 0;
+ void *ip = NULL;
+
+ resolv_get_ip_from_response(&resolution->response, rule->arg.resolv.opts, NULL,
+ 0, &ip, &ip_sin_family, NULL);
+
+ switch (ip_sin_family) {
+ case AF_INET:
+ smp.data.type = SMP_T_IPV4;
+ memcpy(&smp.data.u.ipv4, ip, 4);
+ break;
+ case AF_INET6:
+ smp.data.type = SMP_T_IPV6;
+ memcpy(&smp.data.u.ipv6, ip, 16);
+ break;
+ default:
+ ip = NULL;
+ }
+
+ if (ip) {
+ smp.px = px;
+ smp.sess = sess;
+ smp.strm = s;
+
+ vars_set_by_name(rule->arg.resolv.varname, strlen(rule->arg.resolv.varname), &smp);
+ }
+ }
+ }
+
+ goto release_requester;
+ }
+
+ /* need to configure and start a new DNS resolution */
+ smp = sample_fetch_as_type(px, sess, s, SMP_OPT_DIR_REQ|SMP_OPT_FINAL, rule->arg.resolv.expr, SMP_T_STR);
+ if (smp == NULL)
+ goto end;
+
+ if (action_prepare_for_resolution(s, smp->data.u.str.area, smp->data.u.str.data) == -1)
+ goto end; /* on error, ignore the action */
+
+ s->resolv_ctx.parent = rule;
+
+ HA_SPIN_LOCK(DNS_LOCK, &resolvers->lock);
+ locked = 1;
+
+ resolv_link_resolution(s, OBJ_TYPE_STREAM, 0);
+
+ /* Check if there is a fresh enough response in the cache of our associated resolution */
+ req = s->resolv_ctx.requester;
+ if (!req || !req->resolution)
+ goto release_requester; /* on error, ignore the action */
+ res = req->resolution;
+
+ exp = tick_add(res->last_resolution, resolvers->hold.valid);
+ if (resolvers->t && res->status == RSLV_STATUS_VALID && tick_isset(res->last_resolution)
+ && !tick_is_expired(exp, now_ms)) {
+ goto use_cache;
+ }
+
+ resolv_trigger_resolution(s->resolv_ctx.requester);
+
+ yield:
+ if (flags & ACT_OPT_FINAL)
+ goto release_requester;
+ ret = ACT_RET_YIELD;
+
+ end:
+ leave_resolver_code();
+ if (locked)
+ HA_SPIN_UNLOCK(DNS_LOCK, &resolvers->lock);
+ return ret;
+
+ release_requester:
+ ha_free(&s->resolv_ctx.hostname_dn);
+ s->resolv_ctx.hostname_dn_len = 0;
+ if (s->resolv_ctx.requester) {
+ _resolv_unlink_resolution(s->resolv_ctx.requester);
+ pool_free(resolv_requester_pool, s->resolv_ctx.requester);
+ s->resolv_ctx.requester = NULL;
+ }
+ goto end;
+}
+
+static void release_resolv_action(struct act_rule *rule)
+{
+ release_sample_expr(rule->arg.resolv.expr);
+ free(rule->arg.resolv.varname);
+ free(rule->arg.resolv.resolvers_id);
+ free(rule->arg.resolv.opts);
+}
+
+
+/* parse "do-resolve" action
+ * This action takes the following arguments:
+ * do-resolve(<varName>,<resolversSectionName>,<resolvePrefer>) <expr>
+ *
+ * - <varName> is the variable name where the result of the DNS resolution will be stored
+ * (mandatory)
+ * - <resolversSectionName> is the name of the resolvers section to use to perform the resolution
+ * (mandatory)
+ * - <resolvePrefer> can be either 'ipv4' or 'ipv6' and is the IP family we would like to resolve first
+ * (optional), defaults to ipv6
+ * - <expr> is an HAProxy expression used to fetch the name to be resolved
+ */
+enum act_parse_ret resolv_parse_do_resolve(const char **args, int *orig_arg, struct proxy *px, struct act_rule *rule, char **err)
+{
+ int cur_arg;
+ struct sample_expr *expr;
+ unsigned int where;
+ const char *beg, *end;
+
+ /* orig_arg points to the first argument, but we need to analyse the command itself first */
+ cur_arg = *orig_arg - 1;
+
+ /* locate varName, which is mandatory */
+ beg = strchr(args[cur_arg], '(');
+ if (beg == NULL)
+ goto do_resolve_parse_error;
+ beg = beg + 1; /* beg should points to the first character after opening parenthesis '(' */
+ end = strchr(beg, ',');
+ if (end == NULL)
+ goto do_resolve_parse_error;
+ rule->arg.resolv.varname = my_strndup(beg, end - beg);
+ if (rule->arg.resolv.varname == NULL)
+ goto do_resolve_parse_error;
+
+
+ /* locate resolversSectionName, which is mandatory.
+ * Since next parameters are optional, the delimiter may be comma ','
+ * or closing parenthesis ')'
+ */
+ beg = end + 1;
+ end = strchr(beg, ',');
+ if (end == NULL)
+ end = strchr(beg, ')');
+ if (end == NULL)
+ goto do_resolve_parse_error;
+ rule->arg.resolv.resolvers_id = my_strndup(beg, end - beg);
+ if (rule->arg.resolv.resolvers_id == NULL)
+ goto do_resolve_parse_error;
+
+
+ rule->arg.resolv.opts = calloc(1, sizeof(*rule->arg.resolv.opts));
+ if (rule->arg.resolv.opts == NULL)
+ goto do_resolve_parse_error;
+
+ /* Default priority is ipv6 */
+ rule->arg.resolv.opts->family_prio = AF_INET6;
+
+ /* optional arguments accepted for now:
+ * ipv4 or ipv6
+ */
+ while (*end != ')') {
+ beg = end + 1;
+ end = strchr(beg, ',');
+ if (end == NULL)
+ end = strchr(beg, ')');
+ if (end == NULL)
+ goto do_resolve_parse_error;
+
+ if (strncmp(beg, "ipv4", end - beg) == 0) {
+ rule->arg.resolv.opts->family_prio = AF_INET;
+ }
+ else if (strncmp(beg, "ipv6", end - beg) == 0) {
+ rule->arg.resolv.opts->family_prio = AF_INET6;
+ }
+ else {
+ goto do_resolve_parse_error;
+ }
+ }
+
+ cur_arg = cur_arg + 1;
+
+ expr = sample_parse_expr((char **)args, &cur_arg, px->conf.args.file, px->conf.args.line, err, &px->conf.args, NULL);
+ if (!expr)
+ goto do_resolve_parse_error;
+
+
+ where = 0;
+ if (px->cap & PR_CAP_FE)
+ where |= SMP_VAL_FE_HRQ_HDR;
+ if (px->cap & PR_CAP_BE)
+ where |= SMP_VAL_BE_HRQ_HDR;
+
+ if (!(expr->fetch->val & where)) {
+ memprintf(err,
+ "fetch method '%s' extracts information from '%s', none of which is available here",
+ args[cur_arg-1], sample_src_names(expr->fetch->use));
+ free(expr);
+ return ACT_RET_PRS_ERR;
+ }
+ rule->arg.resolv.expr = expr;
+ rule->action = ACT_CUSTOM;
+ rule->action_ptr = resolv_action_do_resolve;
+ *orig_arg = cur_arg;
+
+ rule->check_ptr = check_action_do_resolve;
+ rule->release_ptr = release_resolv_action;
+
+ return ACT_RET_PRS_OK;
+
+ do_resolve_parse_error:
+ ha_free(&rule->arg.resolv.varname);
+ ha_free(&rule->arg.resolv.resolvers_id);
+ memprintf(err, "Can't parse '%s'. Expects 'do-resolve(<varname>,<resolvers>[,<options>]) <expr>'. Available options are 'ipv4' and 'ipv6'",
+ args[cur_arg]);
+ return ACT_RET_PRS_ERR;
+}
+
+static struct action_kw_list http_req_kws = { { }, {
+ { "do-resolve", resolv_parse_do_resolve, KWF_MATCH_PREFIX },
+ { /* END */ }
+}};
+
+INITCALL1(STG_REGISTER, http_req_keywords_register, &http_req_kws);
+
+static struct action_kw_list tcp_req_cont_actions = {ILH, {
+ { "do-resolve", resolv_parse_do_resolve, KWF_MATCH_PREFIX },
+ { /* END */ }
+}};
+
+INITCALL1(STG_REGISTER, tcp_req_cont_keywords_register, &tcp_req_cont_actions);
+
+/* Check an "http-request do-resolve" action.
+ *
+ * The function returns 1 in success case, otherwise, it returns 0 and err is
+ * filled.
+ */
+int check_action_do_resolve(struct act_rule *rule, struct proxy *px, char **err)
+{
+ struct resolvers *resolvers = NULL;
+
+ if (rule->arg.resolv.resolvers_id == NULL) {
+ memprintf(err,"Proxy '%s': %s", px->id, "do-resolve action without resolvers");
+ return 0;
+ }
+
+ resolvers = find_resolvers_by_id(rule->arg.resolv.resolvers_id);
+ if (resolvers == NULL) {
+ memprintf(err,"Can't find resolvers section '%s' for do-resolve action", rule->arg.resolv.resolvers_id);
+ return 0;
+ }
+ rule->arg.resolv.resolvers = resolvers;
+
+ return 1;
+}
+
+void resolvers_setup_proxy(struct proxy *px)
+{
+ px->last_change = ns_to_sec(now_ns);
+ px->cap = PR_CAP_FE | PR_CAP_BE;
+ px->maxconn = 0;
+ px->conn_retries = 1;
+ px->timeout.server = TICK_ETERNITY;
+ px->timeout.client = TICK_ETERNITY;
+ px->timeout.connect = 1000; // by default same than timeout.resolve
+ px->accept = NULL;
+ px->options2 |= PR_O2_INDEPSTR | PR_O2_SMARTCON;
+}
+
+static int parse_resolve_conf(char **errmsg, char **warnmsg)
+{
+ struct dns_nameserver *newnameserver = NULL;
+ const char *whitespace = "\r\n\t ";
+ char *resolv_line = NULL;
+ int resolv_linenum = 0;
+ FILE *f = NULL;
+ char *address = NULL;
+ struct sockaddr_storage *sk = NULL;
+ struct protocol *proto;
+ int duplicate_name = 0;
+ int err_code = 0;
+
+ if ((resolv_line = malloc(sizeof(*resolv_line) * LINESIZE)) == NULL) {
+ memprintf(errmsg, "out of memory.\n");
+ err_code |= ERR_ALERT | ERR_FATAL;
+ goto resolv_out;
+ }
+
+ if ((f = fopen("/etc/resolv.conf", "r")) == NULL) {
+ if (errmsg)
+ memprintf(errmsg, "failed to open /etc/resolv.conf.");
+ err_code |= ERR_ALERT | ERR_FATAL;
+ goto resolv_out;
+ }
+
+ sk = calloc(1, sizeof(*sk));
+ if (sk == NULL) {
+ if (errmsg)
+ memprintf(errmsg, "parsing [/etc/resolv.conf:%d] : out of memory.", resolv_linenum);
+ err_code |= ERR_ALERT | ERR_FATAL;
+ goto resolv_out;
+ }
+
+ while (fgets(resolv_line, LINESIZE, f) != NULL) {
+ resolv_linenum++;
+ if (strncmp(resolv_line, "nameserver", 10) != 0)
+ continue;
+
+ address = strtok(resolv_line + 10, whitespace);
+ if (address == resolv_line + 10)
+ continue;
+
+ if (address == NULL) {
+ if (warnmsg)
+ memprintf(warnmsg, "%sparsing [/etc/resolv.conf:%d] : nameserver line is missing address.\n",
+ *warnmsg ? *warnmsg : "", resolv_linenum);
+ err_code |= ERR_WARN;
+ continue;
+ }
+
+ duplicate_name = 0;
+ list_for_each_entry(newnameserver, &curr_resolvers->nameservers, list) {
+ if (strcmp(newnameserver->id, address) == 0) {
+ if (warnmsg)
+ memprintf(warnmsg, "%sParsing [/etc/resolv.conf:%d] : generated name for /etc/resolv.conf nameserver '%s' conflicts with another nameserver (declared at %s:%d), it appears to be a duplicate and will be excluded.\n",
+ *warnmsg ? *warnmsg : "", resolv_linenum, address, newnameserver->conf.file, newnameserver->conf.line);
+ err_code |= ERR_WARN;
+ duplicate_name = 1;
+ }
+ }
+
+ if (duplicate_name)
+ continue;
+
+ memset(sk, 0, sizeof(*sk));
+ if (!str2ip2(address, sk, 1)) {
+ if (warnmsg)
+ memprintf(warnmsg, "%sparsing [/etc/resolv.conf:%d] : address '%s' could not be recognized, nameserver will be excluded.\n",
+ *warnmsg ? *warnmsg : "", resolv_linenum, address);
+ err_code |= ERR_WARN;
+ continue;
+ }
+
+ set_host_port(sk, 53);
+
+ proto = protocol_lookup(sk->ss_family, PROTO_TYPE_STREAM, 0);
+ if (!proto || !proto->connect) {
+ if (warnmsg)
+ memprintf(warnmsg, "%sparsing [/etc/resolv.conf:%d] : '%s' : connect() not supported for this address family.\n",
+ *warnmsg ? *warnmsg : "", resolv_linenum, address);
+ err_code |= ERR_WARN;
+ continue;
+ }
+
+ if ((newnameserver = calloc(1, sizeof(*newnameserver))) == NULL) {
+ if (errmsg)
+ memprintf(errmsg, "parsing [/etc/resolv.conf:%d] : out of memory.", resolv_linenum);
+ err_code |= ERR_ALERT | ERR_FATAL;
+ goto resolv_out;
+ }
+
+ if (dns_dgram_init(newnameserver, sk) < 0) {
+ if (errmsg)
+ memprintf(errmsg, "parsing [/etc/resolv.conf:%d] : out of memory.", resolv_linenum);
+ err_code |= ERR_ALERT | ERR_FATAL;
+ free(newnameserver);
+ goto resolv_out;
+ }
+
+ newnameserver->conf.file = strdup("/etc/resolv.conf");
+ if (newnameserver->conf.file == NULL) {
+ if (errmsg)
+ memprintf(errmsg, "parsing [/etc/resolv.conf:%d] : out of memory.", resolv_linenum);
+ err_code |= ERR_ALERT | ERR_FATAL;
+ free(newnameserver);
+ goto resolv_out;
+ }
+
+ newnameserver->id = strdup(address);
+ if (newnameserver->id == NULL) {
+ if (errmsg)
+ memprintf(errmsg, "parsing [/etc/resolv.conf:%d] : out of memory.", resolv_linenum);
+ err_code |= ERR_ALERT | ERR_FATAL;
+ free((char *)newnameserver->conf.file);
+ free(newnameserver);
+ goto resolv_out;
+ }
+
+ newnameserver->parent = curr_resolvers;
+ newnameserver->process_responses = resolv_process_responses;
+ newnameserver->conf.line = resolv_linenum;
+ LIST_APPEND(&curr_resolvers->nameservers, &newnameserver->list);
+ }
+
+resolv_out:
+ free(sk);
+ free(resolv_line);
+ if (f != NULL)
+ fclose(f);
+
+ return err_code;
+}
+
+static int resolvers_new(struct resolvers **resolvers, const char *id, const char *file, int linenum)
+{
+ struct resolvers *r = NULL;
+ struct proxy *p = NULL;
+ int err_code = 0;
+
+ if ((r = calloc(1, sizeof(*r))) == NULL) {
+ err_code |= ERR_ALERT | ERR_ABORT;
+ goto out;
+ }
+
+ /* allocate new proxy to tcp servers */
+ p = calloc(1, sizeof *p);
+ if (!p) {
+ err_code |= ERR_ALERT | ERR_FATAL;
+ goto out;
+ }
+
+ init_new_proxy(p);
+ resolvers_setup_proxy(p);
+ p->parent = r;
+ p->id = strdup(id);
+ p->conf.args.file = p->conf.file = strdup(file);
+ p->conf.args.line = p->conf.line = linenum;
+ r->px = p;
+
+ /* default values */
+ LIST_APPEND(&sec_resolvers, &r->list);
+ r->conf.file = strdup(file);
+ r->conf.line = linenum;
+ r->id = strdup(id);
+ r->query_ids = EB_ROOT;
+ /* default maximum response size */
+ r->accepted_payload_size = 512;
+ /* default hold period for nx, other, refuse and timeout is 30s */
+ r->hold.nx = 30000;
+ r->hold.other = 30000;
+ r->hold.refused = 30000;
+ r->hold.timeout = 30000;
+ r->hold.obsolete = 0;
+ /* default hold period for valid is 10s */
+ r->hold.valid = 10000;
+ r->timeout.resolve = 1000;
+ r->timeout.retry = 1000;
+ r->resolve_retries = 3;
+ LIST_INIT(&r->nameservers);
+ LIST_INIT(&r->resolutions.curr);
+ LIST_INIT(&r->resolutions.wait);
+ HA_SPIN_INIT(&r->lock);
+
+ *resolvers = r;
+
+out:
+ if (err_code & (ERR_FATAL|ERR_ABORT)) {
+ ha_free(&r);
+ ha_free(&p);
+ }
+
+ return err_code;
+}
+
+
+/*
+ * Parse a <resolvers> section.
+ * Returns the error code, 0 if OK, or any combination of :
+ * - ERR_ABORT: must abort ASAP
+ * - ERR_FATAL: we can continue parsing but not start the service
+ * - ERR_WARN: a warning has been emitted
+ * - ERR_ALERT: an alert has been emitted
+ * Only the two first ones can stop processing, the two others are just
+ * indicators.
+ */
+int cfg_parse_resolvers(const char *file, int linenum, char **args, int kwm)
+{
+ const char *err;
+ int err_code = 0;
+ char *errmsg = NULL;
+ char *warnmsg = NULL;
+
+ if (strcmp(args[0], "resolvers") == 0) { /* new resolvers section */
+ if (!*args[1]) {
+ ha_alert("parsing [%s:%d] : missing name for resolvers section.\n", file, linenum);
+ err_code |= ERR_ALERT | ERR_ABORT;
+ goto out;
+ }
+
+ err = invalid_char(args[1]);
+ if (err) {
+ ha_alert("parsing [%s:%d] : character '%c' is not permitted in '%s' name '%s'.\n",
+ file, linenum, *err, args[0], args[1]);
+ err_code |= ERR_ALERT | ERR_ABORT;
+ goto out;
+ }
+
+ list_for_each_entry(curr_resolvers, &sec_resolvers, list) {
+ /* Error if two resolvers owns the same name */
+ if (strcmp(curr_resolvers->id, args[1]) == 0) {
+ ha_alert("Parsing [%s:%d]: resolvers '%s' has same name as another resolvers (declared at %s:%d).\n",
+ file, linenum, args[1], curr_resolvers->conf.file, curr_resolvers->conf.line);
+ err_code |= ERR_ALERT | ERR_ABORT;
+ }
+ }
+
+ err_code |= resolvers_new(&curr_resolvers, args[1], file, linenum);
+ if (err_code & ERR_ALERT) {
+ ha_alert("parsing [%s:%d] : out of memory.\n", file, linenum);
+ goto out;
+ }
+
+ }
+ else if (strcmp(args[0], "nameserver") == 0) { /* nameserver definition */
+ struct dns_nameserver *newnameserver = NULL;
+ struct sockaddr_storage *sk;
+ int port1, port2;
+ struct protocol *proto;
+
+ if (!*args[2]) {
+ ha_alert("parsing [%s:%d] : '%s' expects <name> and <addr>[:<port>] as arguments.\n",
+ file, linenum, args[0]);
+ err_code |= ERR_ALERT | ERR_FATAL;
+ goto out;
+ }
+
+ err = invalid_char(args[1]);
+ if (err) {
+ ha_alert("parsing [%s:%d] : character '%c' is not permitted in server name '%s'.\n",
+ file, linenum, *err, args[1]);
+ err_code |= ERR_ALERT | ERR_FATAL;
+ goto out;
+ }
+
+ list_for_each_entry(newnameserver, &curr_resolvers->nameservers, list) {
+ /* Error if two resolvers owns the same name */
+ if (strcmp(newnameserver->id, args[1]) == 0) {
+ ha_alert("Parsing [%s:%d]: nameserver '%s' has same name as another nameserver (declared at %s:%d).\n",
+ file, linenum, args[1], newnameserver->conf.file, newnameserver->conf.line);
+ err_code |= ERR_ALERT | ERR_FATAL;
+ }
+ }
+
+ sk = str2sa_range(args[2], NULL, &port1, &port2, NULL, &proto, NULL,
+ &errmsg, NULL, NULL, PA_O_RESOLVE | PA_O_PORT_OK | PA_O_PORT_MAND | PA_O_DGRAM | PA_O_STREAM | PA_O_DEFAULT_DGRAM);
+ if (!sk) {
+ ha_alert("parsing [%s:%d] : '%s %s' : %s\n", file, linenum, args[0], args[1], errmsg);
+ err_code |= ERR_ALERT | ERR_FATAL;
+ goto out;
+ }
+
+ if ((newnameserver = calloc(1, sizeof(*newnameserver))) == NULL) {
+ ha_alert("parsing [%s:%d] : out of memory.\n", file, linenum);
+ err_code |= ERR_ALERT | ERR_ABORT;
+ goto out;
+ }
+
+ if (proto && proto->xprt_type == PROTO_TYPE_STREAM) {
+ err_code |= parse_server(file, linenum, args, curr_resolvers->px, NULL,
+ SRV_PARSE_PARSE_ADDR|SRV_PARSE_INITIAL_RESOLVE);
+ if (err_code & (ERR_FATAL|ERR_ABORT)) {
+ err_code |= ERR_ABORT;
+ goto out;
+ }
+
+ if (dns_stream_init(newnameserver, curr_resolvers->px->srv) < 0) {
+ ha_alert("parsing [%s:%d] : out of memory.\n", file, linenum);
+ err_code |= ERR_ALERT|ERR_ABORT;
+ goto out;
+ }
+ }
+ else if (dns_dgram_init(newnameserver, sk) < 0) {
+ ha_alert("parsing [%s:%d] : out of memory.\n", file, linenum);
+ err_code |= ERR_ALERT | ERR_ABORT;
+ goto out;
+ }
+
+ if ((newnameserver->conf.file = strdup(file)) == NULL) {
+ ha_alert("parsing [%s:%d] : out of memory.\n", file, linenum);
+ err_code |= ERR_ALERT | ERR_ABORT;
+ goto out;
+ }
+
+ if ((newnameserver->id = strdup(args[1])) == NULL) {
+ ha_alert("parsing [%s:%d] : out of memory.\n", file, linenum);
+ err_code |= ERR_ALERT | ERR_ABORT;
+ goto out;
+ }
+
+ newnameserver->parent = curr_resolvers;
+ newnameserver->process_responses = resolv_process_responses;
+ newnameserver->conf.line = linenum;
+ /* the nameservers are linked backward first */
+ LIST_APPEND(&curr_resolvers->nameservers, &newnameserver->list);
+ }
+ else if (strcmp(args[0], "parse-resolv-conf") == 0) {
+ err_code |= parse_resolve_conf(&errmsg, &warnmsg);
+ if (err_code & ERR_WARN) {
+ indent_msg(&warnmsg, 8);
+ ha_warning("parsing [%s:%d]: %s\n", file, linenum, warnmsg);
+ ha_free(&warnmsg);
+ }
+ if (err_code & ERR_ALERT) {
+ indent_msg(&errmsg, 8);
+ ha_alert("parsing [%s:%d]: %s\n", file, linenum, errmsg);
+ ha_free(&errmsg);
+ goto out;
+ }
+ }
+ else if (strcmp(args[0], "hold") == 0) { /* hold periods */
+ const char *res;
+ unsigned int time;
+
+ if (!*args[2]) {
+ ha_alert("parsing [%s:%d] : '%s' expects an <event> and a <time> as arguments.\n",
+ file, linenum, args[0]);
+ ha_alert("<event> can be either 'valid', 'nx', 'refused', 'timeout', or 'other'\n");
+ err_code |= ERR_ALERT | ERR_FATAL;
+ goto out;
+ }
+ res = parse_time_err(args[2], &time, TIME_UNIT_MS);
+ if (res == PARSE_TIME_OVER) {
+ ha_alert("parsing [%s:%d]: timer overflow in argument <%s> to <%s>, maximum value is 2147483647 ms (~24.8 days).\n",
+ file, linenum, args[1], args[0]);
+ err_code |= ERR_ALERT | ERR_FATAL;
+ goto out;
+ }
+ else if (res == PARSE_TIME_UNDER) {
+ ha_alert("parsing [%s:%d]: timer underflow in argument <%s> to <%s>, minimum non-null value is 1 ms.\n",
+ file, linenum, args[1], args[0]);
+ err_code |= ERR_ALERT | ERR_FATAL;
+ goto out;
+ }
+ else if (res) {
+ ha_alert("parsing [%s:%d]: unexpected character '%c' in argument to <%s>.\n",
+ file, linenum, *res, args[0]);
+ err_code |= ERR_ALERT | ERR_FATAL;
+ goto out;
+ }
+ if (strcmp(args[1], "nx") == 0)
+ curr_resolvers->hold.nx = time;
+ else if (strcmp(args[1], "other") == 0)
+ curr_resolvers->hold.other = time;
+ else if (strcmp(args[1], "refused") == 0)
+ curr_resolvers->hold.refused = time;
+ else if (strcmp(args[1], "timeout") == 0)
+ curr_resolvers->hold.timeout = time;
+ else if (strcmp(args[1], "valid") == 0)
+ curr_resolvers->hold.valid = time;
+ else if (strcmp(args[1], "obsolete") == 0)
+ curr_resolvers->hold.obsolete = time;
+ else {
+ ha_alert("parsing [%s:%d] : '%s' unknown <event>: '%s', expects either 'nx', 'timeout', 'valid', 'obsolete' or 'other'.\n",
+ file, linenum, args[0], args[1]);
+ err_code |= ERR_ALERT | ERR_FATAL;
+ goto out;
+ }
+
+ }
+ else if (strcmp(args[0], "accepted_payload_size") == 0) {
+ int i = 0;
+
+ if (!*args[1]) {
+ ha_alert("parsing [%s:%d] : '%s' expects <nb> as argument.\n",
+ file, linenum, args[0]);
+ err_code |= ERR_ALERT | ERR_FATAL;
+ goto out;
+ }
+
+ i = atoi(args[1]);
+ if (i < DNS_HEADER_SIZE || i > DNS_MAX_UDP_MESSAGE) {
+ ha_alert("parsing [%s:%d] : '%s' must be between %d and %d inclusive (was %s).\n",
+ file, linenum, args[0], DNS_HEADER_SIZE, DNS_MAX_UDP_MESSAGE, args[1]);
+ err_code |= ERR_ALERT | ERR_FATAL;
+ goto out;
+ }
+
+ curr_resolvers->accepted_payload_size = i;
+ }
+ else if (strcmp(args[0], "resolution_pool_size") == 0) {
+ ha_alert("parsing [%s:%d] : '%s' directive is not supported anymore (it never appeared in a stable release).\n",
+ file, linenum, args[0]);
+ err_code |= ERR_ALERT | ERR_FATAL;
+ goto out;
+ }
+ else if (strcmp(args[0], "resolve_retries") == 0) {
+ if (!*args[1]) {
+ ha_alert("parsing [%s:%d] : '%s' expects <nb> as argument.\n",
+ file, linenum, args[0]);
+ err_code |= ERR_ALERT | ERR_FATAL;
+ goto out;
+ }
+ curr_resolvers->resolve_retries = atoi(args[1]);
+ }
+ else if (strcmp(args[0], "timeout") == 0) {
+ if (!*args[1]) {
+ ha_alert("parsing [%s:%d] : '%s' expects 'retry' or 'resolve' and <time> as arguments.\n",
+ file, linenum, args[0]);
+ err_code |= ERR_ALERT | ERR_FATAL;
+ goto out;
+ }
+ else if (strcmp(args[1], "retry") == 0 ||
+ strcmp(args[1], "resolve") == 0) {
+ const char *res;
+ unsigned int tout;
+
+ if (!*args[2]) {
+ ha_alert("parsing [%s:%d] : '%s %s' expects <time> as argument.\n",
+ file, linenum, args[0], args[1]);
+ err_code |= ERR_ALERT | ERR_FATAL;
+ goto out;
+ }
+ res = parse_time_err(args[2], &tout, TIME_UNIT_MS);
+ if (res == PARSE_TIME_OVER) {
+ ha_alert("parsing [%s:%d]: timer overflow in argument <%s> to <%s %s>, maximum value is 2147483647 ms (~24.8 days).\n",
+ file, linenum, args[2], args[0], args[1]);
+ err_code |= ERR_ALERT | ERR_FATAL;
+ goto out;
+ }
+ else if (res == PARSE_TIME_UNDER) {
+ ha_alert("parsing [%s:%d]: timer underflow in argument <%s> to <%s %s>, minimum non-null value is 1 ms.\n",
+ file, linenum, args[2], args[0], args[1]);
+ err_code |= ERR_ALERT | ERR_FATAL;
+ goto out;
+ }
+ else if (res) {
+ ha_alert("parsing [%s:%d]: unexpected character '%c' in argument to <%s %s>.\n",
+ file, linenum, *res, args[0], args[1]);
+ err_code |= ERR_ALERT | ERR_FATAL;
+ goto out;
+ }
+ if (args[1][2] == 't')
+ curr_resolvers->timeout.retry = tout;
+ else {
+ curr_resolvers->timeout.resolve = tout;
+ curr_resolvers->px->timeout.connect = tout;
+ }
+
+ }
+ else {
+ ha_alert("parsing [%s:%d] : '%s' expects 'retry' or 'resolve' and <time> as arguments got '%s'.\n",
+ file, linenum, args[0], args[1]);
+ err_code |= ERR_ALERT | ERR_FATAL;
+ goto out;
+ }
+ }
+ else if (*args[0] != 0) {
+ ha_alert("parsing [%s:%d] : unknown keyword '%s' in '%s' section\n", file, linenum, args[0], cursection);
+ err_code |= ERR_ALERT | ERR_FATAL;
+ goto out;
+ }
+
+out:
+ free(errmsg);
+ free(warnmsg);
+ return err_code;
+}
+
+/* try to create a "default" resolvers section which uses "/etc/resolv.conf"
+ *
+ * This function is opportunistic and does not try to display errors or warnings.
+ */
+int resolvers_create_default()
+{
+ int err_code = 0;
+
+ if (global.mode & MODE_MWORKER_WAIT) /* does not create the section if in wait mode */
+ return 0;
+
+ /* if the section already exists, do nothing */
+ if (find_resolvers_by_id("default"))
+ return 0;
+
+ curr_resolvers = NULL;
+ err_code |= resolvers_new(&curr_resolvers, "default", "<internal>", 0);
+ if (err_code & ERR_CODE)
+ goto err;
+
+ curr_resolvers->conf.implicit = 1;
+
+ err_code |= parse_resolve_conf(NULL, NULL);
+ if (err_code & ERR_CODE)
+ goto err;
+ /* check if there was any nameserver in the resolvconf file */
+ if (LIST_ISEMPTY(&curr_resolvers->nameservers)) {
+ err_code |= ERR_FATAL;
+ goto err;
+ }
+
+err:
+ if (err_code & ERR_CODE) {
+ resolvers_destroy(curr_resolvers);
+ curr_resolvers = NULL;
+ }
+
+ /* we never return an error there, we only try to create this section
+ * if that's possible */
+ return 0;
+}
+
+int cfg_post_parse_resolvers()
+{
+ int err_code = 0;
+ struct server *srv;
+
+ if (curr_resolvers) {
+
+ /* prepare forward server descriptors */
+ if (curr_resolvers->px) {
+ srv = curr_resolvers->px->srv;
+ while (srv) {
+ /* init ssl if needed */
+ if (srv->use_ssl == 1 && xprt_get(XPRT_SSL) && xprt_get(XPRT_SSL)->prepare_srv) {
+ if (xprt_get(XPRT_SSL)->prepare_srv(srv)) {
+ ha_alert("unable to prepare SSL for server '%s' in resolvers section '%s'.\n", srv->id, curr_resolvers->id);
+ err_code |= ERR_ALERT | ERR_FATAL;
+ break;
+ }
+ }
+ srv = srv->next;
+ }
+ }
+ }
+ curr_resolvers = NULL;
+ return err_code;
+}
+
+REGISTER_CONFIG_SECTION("resolvers", cfg_parse_resolvers, cfg_post_parse_resolvers);
+REGISTER_POST_DEINIT(resolvers_deinit);
+REGISTER_CONFIG_POSTPARSER("dns runtime resolver", resolvers_finalize_config);
+REGISTER_PRE_CHECK(resolvers_create_default);