From 7e2de117961fe247d8aa16af2ab762990965c239 Mon Sep 17 00:00:00 2001 From: Jakub Hrozek Date: Wed, 25 May 2011 16:23:50 +0200 Subject: Check DNS records before updating https://fedorahosted.org/sssd/ticket/802 --- src/providers/ipa/ipa_dyndns.c | 484 +++++++++++++++++++++++++++++++++++++++-- 1 file changed, 463 insertions(+), 21 deletions(-) (limited to 'src/providers/ipa/ipa_dyndns.c') diff --git a/src/providers/ipa/ipa_dyndns.c b/src/providers/ipa/ipa_dyndns.c index 72e4ba4d..6034a5bb 100644 --- a/src/providers/ipa/ipa_dyndns.c +++ b/src/providers/ipa/ipa_dyndns.c @@ -41,6 +41,9 @@ #define IPA_DYNDNS_TIMEOUT 15 +#define IPA_DYNDNS_REMOVE_A 0x1 +#define IPA_DYNDNS_REMOVE_AAAA 0x2 + struct ipa_ipaddress { struct ipa_ipaddress *next; struct ipa_ipaddress *prev; @@ -55,6 +58,8 @@ struct ipa_dyndns_ctx { char *hostname; struct ipa_ipaddress *addresses; bool use_server_with_nsupdate; + uint8_t remove_af; + enum restrict_family family_order; }; @@ -62,6 +67,109 @@ static struct tevent_req * ipa_dyndns_update_send(struct ipa_options *ctx); static void ipa_dyndns_update_done(struct tevent_req *req); +static errno_t +ipa_ipaddress_list_as_string_list(TALLOC_CTX *mem_ctx, + struct ipa_ipaddress *ipa_addr_list, + char ***_straddrs) +{ + struct ipa_ipaddress *ipa_addr; + size_t count; + int ai; + char **straddrs; + const char *ip; + char ip_addr[INET6_ADDRSTRLEN]; + errno_t ret; + + count = 0; + DLIST_FOR_EACH(ipa_addr, ipa_addr_list) { + count++; + } + + straddrs = talloc_array(mem_ctx, char *, count+1); + if (straddrs == NULL) { + return ENOMEM; + } + + ai = 0; + DLIST_FOR_EACH(ipa_addr, ipa_addr_list) { + switch(ipa_addr->addr->ss_family) { + case AF_INET: + errno = 0; + ip = inet_ntop(ipa_addr->addr->ss_family, + &(((struct sockaddr_in *)ipa_addr->addr)->sin_addr), + ip_addr, INET6_ADDRSTRLEN); + if (ip == NULL) { + ret = errno; + goto fail; + } + break; + + case AF_INET6: + errno = 0; + ip = inet_ntop(ipa_addr->addr->ss_family, + &(((struct sockaddr_in6 *)ipa_addr->addr)->sin6_addr), + ip_addr, INET6_ADDRSTRLEN); + if (ip == NULL) { + ret = errno; + goto fail; + } + break; + + default: + DEBUG(0, ("Unknown address family\n")); + continue; + } + + straddrs[ai] = talloc_strdup(straddrs, ip); + if (straddrs[ai] == NULL) { + ret = ENOMEM; + goto fail; + } + ai++; + } + + straddrs[count] = NULL; + *_straddrs = straddrs; + return EOK; + +fail: + talloc_free(straddrs); + return ret; +} + + +errno_t ipa_dyndns_init(TALLOC_CTX *mem_ctx, + struct be_ctx *be_ctx, + struct ipa_options *ctx) +{ + errno_t ret; + int resolv_timeout; + + ret = confdb_get_int(be_ctx->cdb, be_ctx, be_ctx->conf_path, + CONFDB_DOMAIN_RESOLV_TIMEOUT, + RESOLV_DEFAULT_TIMEOUT, &resolv_timeout); + if (ret != EOK) { + DEBUG(1, ("Could get the timeout parameter from confdb\n")); + return ret; + } + + ret = resolv_init(be_ctx, be_ctx->ev, resolv_timeout, &ctx->resolv); + if (ret != EOK) { + DEBUG(1, ("Could not set up resolver context\n")); + return ret; + } + + ret = be_add_online_cb(be_ctx, be_ctx, + ipa_dyndns_update, + ctx, NULL); + if (ret != EOK) { + DEBUG(1, ("Could not set up online callback\n")); + return ret; + } + + return EOK; +} + void ipa_dyndns_update(void *pvt) { struct ipa_options *ctx = talloc_get_type(pvt, struct ipa_options); @@ -266,11 +374,26 @@ static int ipa_dyndns_add_ldap_iface(struct ipa_dyndns_ctx *state, return EOK; } +static struct tevent_req * +ipa_dyndns_update_get_addrs_send(TALLOC_CTX *mem_ctx, + struct ipa_dyndns_ctx *ctx, + enum restrict_family family_order); +static errno_t +ipa_dyndns_update_get_addrs_recv(struct tevent_req *req, + TALLOC_CTX *mem_ctx, + char ***_addrlist); + +static errno_t +ipa_dyndns_gss_tsig_update_setup_check(struct ipa_dyndns_ctx *state); +static void +ipa_dyndns_gss_tsig_update_check(struct tevent_req *subreq); + static int ipa_dyndns_gss_tsig_update_step(struct tevent_req *req) { struct ipa_dyndns_ctx *state = tevent_req_data(req, struct ipa_dyndns_ctx); char *ipa_hostname; struct tevent_req *subreq; + errno_t ret; /* Get the IPA hostname */ ipa_hostname = dp_opt_get_string(state->ipa_ctx->basic, @@ -283,25 +406,332 @@ static int ipa_dyndns_gss_tsig_update_step(struct tevent_req *req) } state->hostname = talloc_strdup(state, ipa_hostname); - if(state->hostname == NULL) { + if (state->hostname == NULL) { return ENOMEM; } - /* In the future, it might be best to check that an update - * needs to be run before running it, but this is such a - * rare event that it's probably fine to just run an update - * every time we come online. - */ - subreq = ipa_dyndns_gss_tsig_update_send(state); - if(subreq == NULL) { + DEBUG(7, ("Checking if the update is needed\n")); + + ret = ipa_dyndns_gss_tsig_update_setup_check(state); + if (ret != EOK) { + return ret; + } + + subreq = ipa_dyndns_update_get_addrs_send(state, state, + state->family_order); + if (subreq == NULL) { return ENOMEM; } tevent_req_set_callback(subreq, - ipa_dyndns_gss_tsig_update_done, + ipa_dyndns_gss_tsig_update_check, req); return EOK; } +static errno_t +ipa_dyndns_gss_tsig_update_setup_check(struct ipa_dyndns_ctx *state) +{ + errno_t ret; + + if (dp_opt_get_string(state->ipa_ctx->basic, IPA_DYNDNS_IFACE)) { + ret = resolv_get_family_order(state->ipa_ctx->id_ctx->be->cdb, + state->ipa_ctx->id_ctx->be->conf_path, + &state->family_order); + if (ret != EOK) { + return ret; + } + + /* Unless one family is restricted, just replace all + * address families during the update + */ + switch (state->family_order) { + case IPV4_ONLY: + state->remove_af |= IPA_DYNDNS_REMOVE_A; + break; + case IPV6_ONLY: + state->remove_af |= IPA_DYNDNS_REMOVE_AAAA; + break; + case IPV4_FIRST: + case IPV6_FIRST: + state->remove_af |= (IPA_DYNDNS_REMOVE_A | + IPA_DYNDNS_REMOVE_AAAA); + break; + } + } else { + /* If the interface isn't specified, we ONLY want to have the address + * that's connected to the LDAP server stored, so we need to check + * (and later remove) both address families. + */ + state->family_order = IPV4_FIRST; + state->remove_af = (IPA_DYNDNS_REMOVE_A | + IPA_DYNDNS_REMOVE_AAAA); + } + + return EOK; +} + +static void +ipa_dyndns_gss_tsig_update_check(struct tevent_req *subreq) +{ + struct tevent_req *req = + tevent_req_callback_data(subreq, struct tevent_req); + struct ipa_dyndns_ctx *state = tevent_req_data(req, + struct ipa_dyndns_ctx); + + errno_t ret; + char **str_dnslist = NULL, **str_local_list = NULL; + char **dns_only = NULL, **local_only = NULL; + bool do_update = false; + int i; + TALLOC_CTX *tmp_ctx; + + tmp_ctx = talloc_new(NULL); + if (!tmp_ctx) { + ret = ENOMEM; + goto fail; + } + + ret = ipa_dyndns_update_get_addrs_recv(subreq, tmp_ctx, &str_dnslist); + talloc_zfree(subreq); + if (ret != EOK) { + DEBUG(3, ("Getting the current list of addresses failed [%d]: %s\n", + ret, strerror(ret))); + goto fail; + } + + ret = ipa_ipaddress_list_as_string_list(tmp_ctx, + state->addresses, &str_local_list); + if (ret != EOK) { + DEBUG(3, ("Converting DNS IP addresses to strings failed: [%d]: %s\n", + ret, strerror(ret))); + goto fail; + } + + /* Compare the lists */ + ret = diff_string_lists(tmp_ctx, str_dnslist, str_local_list, + &dns_only, &local_only, NULL); + if (ret != EOK) { + DEBUG(3, ("diff_string_lists failed: [%d]: %s\n", ret, strerror(ret))); + goto fail; + } + + if (dns_only) { + for (i=0; dns_only[i]; i++) { + DEBUG(7, ("Address in DNS only: %s\n", dns_only[i])); + do_update = true; + } + } + + if (local_only) { + for (i=0; local_only[i]; i++) { + DEBUG(7, ("Address on localhost only: %s\n", local_only[i])); + do_update = true; + } + } + + if (do_update) { + DEBUG(6, ("Detected IP addresses change, will perform an update\n")); + subreq = ipa_dyndns_gss_tsig_update_send(state); + if(subreq == NULL) { + ret = ENOMEM; + goto fail; + } + tevent_req_set_callback(subreq, + ipa_dyndns_gss_tsig_update_done, + req); + talloc_free(tmp_ctx); + return; + } + + DEBUG(6, ("No DNS update needed, addresses did not change\n")); + tevent_req_done(req); + talloc_free(tmp_ctx); + return; + +fail: + talloc_free(tmp_ctx); + tevent_req_error(req, ret); +} + +struct ipa_dyndns_update_get_addrs_state { + struct ipa_dyndns_ctx *dctx; + + enum host_database *db; + enum restrict_family family_order; + + char **addrlist; + size_t count; +}; + +static void ipa_dyndns_update_get_addrs_done(struct tevent_req *subreq); +static errno_t ipa_dyndns_update_get_addrs_step(struct tevent_req *req); + +static struct tevent_req * +ipa_dyndns_update_get_addrs_send(TALLOC_CTX *mem_ctx, + struct ipa_dyndns_ctx *ctx, + enum restrict_family family_order) +{ + errno_t ret; + struct tevent_req *req; + struct ipa_dyndns_update_get_addrs_state *state; + + req = tevent_req_create(mem_ctx, &state, + struct ipa_dyndns_update_get_addrs_state); + if (req == NULL) { + return NULL; + } + state->dctx = ctx; + state->family_order = family_order; + + state->db = talloc_array(state, enum host_database, 2); + if (state->db == NULL) { + ret = ENOMEM; + goto immediate; + } + state->db[0] = DB_DNS; + state->db[1] = DB_SENTINEL; + + ret = ipa_dyndns_update_get_addrs_step(req); + if (ret != EOK) { + goto immediate; + } + +immediate: + if (ret != EOK) { + tevent_req_error(req, ret); + tevent_req_post(req, ctx->ipa_ctx->id_ctx->be->ev); + } + return req; +} + +static errno_t +ipa_dyndns_update_get_addrs_step(struct tevent_req *req) +{ + struct tevent_req *subreq; + struct ipa_dyndns_update_get_addrs_state *state = tevent_req_data(req, + struct ipa_dyndns_update_get_addrs_state); + + subreq = resolv_gethostbyname_send(state, + state->dctx->ipa_ctx->id_ctx->be->ev, + state->dctx->ipa_ctx->resolv, + state->dctx->hostname, + state->family_order, + state->db); + if (!subreq) { + return ENOMEM; + } + + tevent_req_set_callback(subreq, ipa_dyndns_update_get_addrs_done, req); + return EOK; +} + +static void +ipa_dyndns_update_get_addrs_done(struct tevent_req *subreq) +{ + int ret; + size_t count; + struct tevent_req *req = + tevent_req_callback_data(subreq, struct tevent_req); + struct ipa_dyndns_update_get_addrs_state *state = tevent_req_data(req, + struct ipa_dyndns_update_get_addrs_state); + struct resolv_hostent *rhostent; + int i; + + ret = resolv_gethostbyname_recv(subreq, state, NULL, NULL, + &rhostent); + talloc_zfree(subreq); + + /* If the retry did not match, simply quit */ + if (ret == ENOENT) { + /* If the resolver is set to honor both address families + * retry the second one + */ + if (((state->family_order == IPV4_FIRST && + rhostent->family == AF_INET) || + (state->family_order == IPV6_FIRST && + rhostent->family == AF_INET6))) { + + state->family_order = (state->family_order == IPV4_FIRST) ? \ + IPV6_ONLY : IPV4_ONLY; + + ret = ipa_dyndns_update_get_addrs_step(req); + if (ret != EOK) { + tevent_req_error(req, ret); + } + return; + } + + /* Nothing to retry, simply quit */ + tevent_req_done(req); + return; + } else if (ret != EOK) { + tevent_req_error(req, ret); + return; + } + + /* EOK */ + + for (count=0; rhostent->addr_list[count]; count++); + + state->addrlist = talloc_realloc(state, state->addrlist, char *, + state->count + count + 1); + if (!state->addrlist) { + tevent_req_error(req, ENOMEM); + return; + } + + for (i=0; i < count; i++) { + state->addrlist[state->count + i] = \ + resolv_get_string_address_index(state->addrlist, + rhostent, i); + + if (state->addrlist[state->count + i] == NULL) { + tevent_req_error(req, ENOMEM); + return; + } + } + state->count += count; + state->addrlist[state->count] = NULL; + + /* If the resolver is set to honor both address families + * and the first one matched, retry the second one to + * get the complete list. + */ + if (((state->family_order == IPV4_FIRST && + rhostent->family == AF_INET) || + (state->family_order == IPV6_FIRST && + rhostent->family == AF_INET6))) { + + state->family_order = (state->family_order == IPV4_FIRST) ? \ + IPV6_ONLY : IPV4_ONLY; + + ret = ipa_dyndns_update_get_addrs_step(req); + if (ret != EOK) { + tevent_req_error(req, ret); + } + return; + } + + /* The second address matched either immediatelly or after a retry. + * No need to retry again. */ + tevent_req_done(req); + return; +} + +static errno_t +ipa_dyndns_update_get_addrs_recv(struct tevent_req *req, + TALLOC_CTX *mem_ctx, + char ***_addrlist) +{ + struct ipa_dyndns_update_get_addrs_state *state = tevent_req_data(req, + struct ipa_dyndns_update_get_addrs_state); + + TEVENT_REQ_RETURN_ON_ERROR(req); + + *_addrlist = talloc_steal(mem_ctx, state->addrlist); + return EOK; +} + struct ipa_nsupdate_ctx { char *update_msg; struct ipa_dyndns_ctx *dyndns_ctx; @@ -312,6 +742,7 @@ struct ipa_nsupdate_ctx { static int create_nsupdate_message(struct ipa_nsupdate_ctx *ctx, + uint8_t remove_af, bool use_server_with_nsupdate); static struct tevent_req * @@ -335,7 +766,8 @@ ipa_dyndns_gss_tsig_update_send(struct ipa_dyndns_ctx *ctx) state->child_status = 0; /* Format the message to pass to the nsupdate command */ - ret = create_nsupdate_message(state, ctx->use_server_with_nsupdate); + ret = create_nsupdate_message(state, ctx->remove_af, + ctx->use_server_with_nsupdate); if (ret != EOK) { goto failed; } @@ -360,6 +792,7 @@ struct nsupdate_send_ctx { }; static int create_nsupdate_message(struct ipa_nsupdate_ctx *ctx, + uint8_t remove_af, bool use_server_with_nsupdate) { int ret, i; @@ -382,7 +815,7 @@ static int create_nsupdate_message(struct ipa_nsupdate_ctx *ctx, } /* The DNS zone for IPA is the lower-case - * version of hte IPA domain + * version of the IPA domain */ for(i = 0; zone[i] != '\0'; i++) { zone[i] = tolower(zone[i]); @@ -418,15 +851,24 @@ static int create_nsupdate_message(struct ipa_nsupdate_ctx *ctx, goto done; } - /* Remove any existing entries */ - ctx->update_msg = talloc_asprintf_append(ctx->update_msg, - "update delete %s. in A\nsend\n" - "update delete %s. in AAAA\nsend\n", - ctx->dyndns_ctx->hostname, - ctx->dyndns_ctx->hostname); - if (ctx->update_msg == NULL) { - ret = ENOMEM; - goto done; + /* Remove existing entries as needed */ + if (remove_af & IPA_DYNDNS_REMOVE_A) { + ctx->update_msg = talloc_asprintf_append(ctx->update_msg, + "update delete %s. in A\nsend\n", + ctx->dyndns_ctx->hostname); + if (ctx->update_msg == NULL) { + ret = ENOMEM; + goto done; + } + } + if (remove_af & IPA_DYNDNS_REMOVE_AAAA) { + ctx->update_msg = talloc_asprintf_append(ctx->update_msg, + "update delete %s. in AAAA\nsend\n", + ctx->dyndns_ctx->hostname); + if (ctx->update_msg == NULL) { + ret = ENOMEM; + goto done; + } } DLIST_FOR_EACH(new_record, ctx->dyndns_ctx->addresses) { @@ -746,5 +1188,5 @@ static void ipa_dyndns_update_done(struct tevent_req *req) return; } - DEBUG(1,("Updated DNS entry\n")); + DEBUG(1, ("DNS update finished\n")); } -- cgit