summaryrefslogtreecommitdiff
path: root/src/resolv
diff options
context:
space:
mode:
Diffstat (limited to 'src/resolv')
-rw-r--r--src/resolv/async_resolv.c436
-rw-r--r--src/resolv/async_resolv.h56
2 files changed, 287 insertions, 205 deletions
diff --git a/src/resolv/async_resolv.c b/src/resolv/async_resolv.c
index 2f156e3a..c05628a3 100644
--- a/src/resolv/async_resolv.c
+++ b/src/resolv/async_resolv.c
@@ -56,6 +56,8 @@
#define DNS__16BIT(p) (((p)[0] << 8) | (p)[1])
#define DNS_HEADER_ANCOUNT(h) DNS__16BIT((h) + 6)
+enum host_database default_host_dbs[] = { DB_FILES, DB_DNS, DB_SENTINEL };
+
struct fd_watch {
struct fd_watch *prev;
struct fd_watch *next;
@@ -333,7 +335,8 @@ recreate_ares_channel(struct resolv_ctx *ctx)
options.sock_state_cb = fd_event;
options.sock_state_cb_data = ctx;
options.timeout = ctx->timeout * 1000;
- options.lookups = discard_const("fb");
+ /* Only affects ares_gethostbyname */
+ options.lookups = discard_const("f");
options.tries = 1;
ret = ares_init_options(&new_channel, &options,
ARES_OPT_SOCK_STATE_CB |
@@ -401,64 +404,6 @@ resolv_reread_configuration(void)
}
}
-struct hostent *
-resolv_copy_hostent(TALLOC_CTX *mem_ctx, struct hostent *src)
-{
- struct hostent *ret;
- int len;
- int i;
-
- ret = talloc_zero(mem_ctx, struct hostent);
- if (ret == NULL) {
- return NULL;
- }
-
- if (src->h_name != NULL) {
- ret->h_name = talloc_strdup(ret, src->h_name);
- if (ret->h_name == NULL) {
- goto fail;
- }
- }
- if (src->h_aliases != NULL) {
- for (len = 0; src->h_aliases[len] != NULL; len++);
- ret->h_aliases = talloc_size(ret, sizeof(char *) * (len + 1));
- if (ret->h_aliases == NULL) {
- goto fail;
- }
- for (i = 0; i < len; i++) {
- ret->h_aliases[i] = talloc_strdup(ret->h_aliases, src->h_aliases[i]);
- if (ret->h_aliases[i] == NULL) {
- goto fail;
- }
- }
- ret->h_aliases[len] = NULL;
- }
- ret->h_addrtype = src->h_addrtype;
- ret->h_length = src->h_length;
- if (src->h_addr_list != NULL) {
- for (len = 0; src->h_addr_list[len] != NULL; len++);
- ret->h_addr_list = talloc_size(ret, sizeof(char *) * (len + 1));
- if (ret->h_addr_list == NULL) {
- goto fail;
- }
- for (i = 0; i < len; i++) {
- ret->h_addr_list[i] = talloc_memdup(ret->h_addr_list,
- src->h_addr_list[i],
- ret->h_length);
- if (ret->h_addr_list[i] == NULL) {
- goto fail;
- }
- }
- ret->h_addr_list[len] = NULL;
- }
-
- return ret;
-
-fail:
- talloc_free(ret);
- return NULL;
-}
-
static errno_t
resolv_copy_in_addr(TALLOC_CTX *mem_ctx, struct resolv_addr *ret,
struct ares_addrttl *attl)
@@ -529,7 +474,7 @@ fail:
}
struct resolv_hostent *
-resolv_copy_hostent2(TALLOC_CTX *mem_ctx, struct hostent *src)
+resolv_copy_hostent(TALLOC_CTX *mem_ctx, struct hostent *src)
{
struct resolv_hostent *ret;
int len;
@@ -678,7 +623,7 @@ resolv_gethostbyname_files_send(TALLOC_CTX *mem_ctx,
&hostent);
if (state->status == ARES_SUCCESS) {
- state->rhostent = resolv_copy_hostent2(state, hostent);
+ state->rhostent = resolv_copy_hostent(state, hostent);
if (state->rhostent == NULL) {
tevent_req_error(req, ENOMEM);
goto done;
@@ -979,30 +924,46 @@ resolv_gethostbyname_dns_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
struct gethostbyname_state {
struct resolv_ctx *resolv_ctx;
+ struct tevent_context *ev;
+
/* Part of the query. */
const char *name;
int family;
+
/* In which order to use IPv4, or v6 */
enum restrict_family family_order;
+
+ /* Known hosts databases and index to the current one */
+ enum host_database *db;
+ int dbi;
+
/* These are returned by ares. The hostent struct will be freed
* when the user callback returns. */
- struct hostent *hostent;
+ struct resolv_hostent *rhostent;
int status;
int timeouts;
int retrying;
};
-static void
-ares_gethostbyname_wakeup(struct tevent_req *req);
+static errno_t
+resolv_gethostbyname_address(TALLOC_CTX *mem_ctx, const char *address,
+ struct resolv_hostent **_rhostent);
+static inline int
+resolv_gethostbyname_family_init(enum restrict_family family_order);
+static bool
+resolv_is_address(const char *name);
+static errno_t
+resolv_gethostbyname_step(struct tevent_req *req);
struct tevent_req *
resolv_gethostbyname_send(TALLOC_CTX *mem_ctx, struct tevent_context *ev,
struct resolv_ctx *ctx, const char *name,
- enum restrict_family family_order)
+ enum restrict_family family_order,
+ enum host_database *db)
{
- struct tevent_req *req, *subreq;
+ struct tevent_req *req;
struct gethostbyname_state *state;
- struct timeval tv = { 0, 0 };
+ errno_t ret;
if (ctx->channel == NULL) {
DEBUG(1, ("Invalid ares channel - this is likely a bug\n"));
@@ -1010,141 +971,279 @@ resolv_gethostbyname_send(TALLOC_CTX *mem_ctx, struct tevent_context *ev,
}
req = tevent_req_create(mem_ctx, &state, struct gethostbyname_state);
- if (req == NULL)
+ if (req == NULL) {
return NULL;
+ }
state->resolv_ctx = ctx;
+ state->ev = ev;
state->name = name;
- state->hostent = NULL;
+ state->rhostent = NULL;
state->status = 0;
state->timeouts = 0;
state->retrying = 0;
state->family_order = family_order;
- state->family = (family_order < IPV6_ONLY) ? AF_INET : AF_INET6;
+ state->family = resolv_gethostbyname_family_init(state->family_order);
+ state->db = db;
+ state->dbi = 0;
+
+ /* Do not attempt to resolve IP addresses */
+ if (resolv_is_address(state->name)) {
+ ret = resolv_gethostbyname_address(state, state->name,
+ &state->rhostent);
+ if (ret != EOK) {
+ DEBUG(1, ("Canot create a fake hostent structure\n"));
+ talloc_zfree(req);
+ return NULL;
+ }
- DEBUG(4, ("Trying to resolve %s record of '%s'\n",
- state->family == AF_INET ? "A" : "AAAA",
- state->name));
+ tevent_req_done(req);
+ tevent_req_post(req, ev);
+ return req;
+ }
- /* We need to have a wrapper around ares_gethostbyname(), because
- * ares_gethostbyname() can in some cases call it's callback immediately.
- * This would not let our caller to set a callback for req. */
- subreq = tevent_wakeup_send(req, ev, tv);
- if (subreq == NULL) {
- DEBUG(1, ("Failed to add critical timer to run next operation!\n"));
+ ret = resolv_gethostbyname_step(req);
+ if (ret != EOK) {
+ DEBUG(1, ("Cannot start the resolving\n"));
talloc_zfree(req);
return NULL;
}
- tevent_req_set_callback(subreq, ares_gethostbyname_wakeup, req);
- schedule_timeout_watcher(ev, ctx);
return req;
}
-static void
-resolv_gethostbyname_next_done(void *arg, int status, int timeouts, struct hostent *hostent);
+static bool
+resolv_is_address(const char *name)
+{
+ struct addrinfo hints;
+ struct addrinfo *res = NULL;
+ int ret;
-static void
-resolv_gethostbyname_done(void *arg, int status, int timeouts, struct hostent *hostent)
+ memset((void *) &hints, 0, sizeof(struct addrinfo));
+ hints.ai_family = AF_UNSPEC;
+ hints.ai_flags = AI_NUMERICHOST; /* No network lookups */
+
+ ret = getaddrinfo(name, NULL, &hints, &res);
+ freeaddrinfo(res);
+ if (ret != 0) {
+ if (ret == -2) {
+ DEBUG(9, ("[%s] does not look like an IP address\n", name));
+ } else {
+ DEBUG(2, ("getaddrinfo failed [%d]: %s\n",
+ ret, gai_strerror(ret)));
+ }
+ }
+
+ return ret == 0;
+}
+
+static errno_t
+resolv_gethostbyname_address(TALLOC_CTX *mem_ctx, const char *address,
+ struct resolv_hostent **_rhostent)
{
- struct tevent_req *req = talloc_get_type(arg, struct tevent_req);
- struct gethostbyname_state *state = tevent_req_data(req, struct gethostbyname_state);
+ struct resolv_hostent *rhostent;
+ TALLOC_CTX *tmp_ctx;
+ errno_t ret;
+ int family;
- if (state->retrying == 0 && status == ARES_EDESTRUCTION
- && state->resolv_ctx->channel != NULL) {
- state->retrying = 1;
- ares_gethostbyname(state->resolv_ctx->channel, state->name,
- state->family, resolv_gethostbyname_done, req);
- return;
+ tmp_ctx = talloc_new(NULL);
+ if (!tmp_ctx) return ENOMEM;
+
+ rhostent = talloc_zero(tmp_ctx, struct resolv_hostent);
+ if (!rhostent) {
+ ret = ENOMEM;
+ goto done;
}
- unschedule_timeout_watcher(state->resolv_ctx);
+ rhostent->name = talloc_strdup(rhostent, address);
+ rhostent->addr_list = talloc_array(rhostent, struct resolv_addr *, 2);
- if (hostent != NULL) {
- state->hostent = resolv_copy_hostent(req, hostent);
- if (state->hostent == NULL) {
- tevent_req_error(req, ENOMEM);
- return;
+ if (!rhostent->name ||
+ !rhostent->addr_list) {
+ ret = ENOMEM;
+ goto done;
+ }
+
+ rhostent->addr_list[0] = talloc_zero(rhostent->addr_list,
+ struct resolv_addr);
+ if (!rhostent->addr_list[0]) {
+ ret = ENOMEM;
+ goto done;
+ }
+ rhostent->addr_list[0]->ipaddr = talloc_array(rhostent->addr_list[0],
+ uint8_t,
+ sizeof(struct in6_addr));
+ if (!rhostent->addr_list[0]->ipaddr) {
+ ret = ENOMEM;
+ goto done;
+ }
+
+ family = AF_INET;
+ ret = inet_pton(family, address,
+ rhostent->addr_list[0]->ipaddr);
+ if (ret != 1) {
+ family = AF_INET6;
+ ret = inet_pton(family, address,
+ rhostent->addr_list[0]->ipaddr);
+ if (ret != 1) {
+ DEBUG(1, ("Could not parse address as neither v4 nor v6\n"));
+ ret = EINVAL;
+ goto done;
}
- } else {
- state->hostent = NULL;
}
- state->status = status;
- state->timeouts = timeouts;
- if (status != ARES_SUCCESS) {
- if (status == ARES_ENOTFOUND || status == ARES_ENODATA) {
- if (state->family_order == IPV4_FIRST) {
- state->family = AF_INET6;
- } else if (state->family_order == IPV6_FIRST) {
- state->family = AF_INET;
- } else {
- tevent_req_error(req, return_code(status));
- return;
- }
+ rhostent->addr_list[0]->ttl = RESOLV_DEFAULT_TTL;
+ rhostent->addr_list[1] = NULL;
+ rhostent->family = family;
+ rhostent->aliases = NULL;
- state->retrying = 0;
- state->timeouts = 0;
- DEBUG(4, ("Trying to resolve %s record of '%s'\n",
- state->family == AF_INET ? "A" : "AAAA",
- state->name));
- schedule_timeout_watcher(state->resolv_ctx->ev_ctx,
- state->resolv_ctx);
- ares_gethostbyname(state->resolv_ctx->channel, state->name,
- state->family, resolv_gethostbyname_next_done,
- req);
- return;
+ *_rhostent = talloc_move(mem_ctx, &rhostent);
+ ret = EOK;
+done:
+ talloc_free(tmp_ctx);
+ return ret;
+}
+
+static inline int
+resolv_gethostbyname_family_init(enum restrict_family family_order)
+{
+ switch(family_order) {
+ case IPV4_ONLY:
+ case IPV4_FIRST:
+ return AF_INET;
+ case IPV6_ONLY:
+ case IPV6_FIRST:
+ return AF_INET6;
+ }
+
+ DEBUG(1, ("Unknown address family order %d\n", family_order));
+ return -1;
+}
+
+static int
+resolv_gethostbyname_next(struct gethostbyname_state *state)
+{
+ if (state->family_order == IPV4_FIRST &&
+ state->family == AF_INET) {
+ state->family = AF_INET6;
+ return EOK;
+ } else if (state->family_order == IPV6_FIRST &&
+ state->family == AF_INET6) {
+ state->family = AF_INET;
+ return EOK;
+ } else {
+ /* No more address families for this DB, check if
+ * there is another DB to try */
+ DEBUG(5, ("No more address families to retry\n"));
+ state->dbi++;
+ if (state->db[state->dbi] != DB_SENTINEL) {
+ state->family = resolv_gethostbyname_family_init(
+ state->family_order);
+ return EOK;
}
+ }
- /* Any other error indicates a server error,
- * so don't bother trying again
- */
- tevent_req_error(req, return_code(status));
+ DEBUG(4, ("No more hosts databases to retry\n"));
+ return ENOENT;
+}
+
+static void
+resolv_gethostbyname_done(struct tevent_req *subreq);
+
+static errno_t
+resolv_gethostbyname_step(struct tevent_req *req)
+{
+ struct gethostbyname_state *state = tevent_req_data(req,
+ struct gethostbyname_state);
+ struct tevent_req *subreq;
+
+ switch(state->db[state->dbi]) {
+ case DB_FILES:
+ DEBUG(8, ("Querying files\n"));
+ subreq = resolv_gethostbyname_files_send(state, state->ev,
+ state->resolv_ctx,
+ state->name,
+ state->family);
+ break;
+ case DB_DNS:
+ DEBUG(8, ("Querying DNS\n"));
+ subreq = resolv_gethostbyname_dns_send(state, state->ev,
+ state->resolv_ctx,
+ state->name,
+ state->family);
+ break;
+ default:
+ DEBUG(1, ("Invalid hosts database\n"));
+ return EINVAL;
}
- else {
- tevent_req_done(req);
+
+ if (subreq == NULL) {
+ return ENOMEM;
}
+
+ tevent_req_set_callback(subreq, resolv_gethostbyname_done, req);
+ return EOK;
}
static void
-resolv_gethostbyname_next_done(void *arg, int status, int timeouts, struct hostent *hostent)
+resolv_gethostbyname_done(struct tevent_req *subreq)
{
- struct tevent_req *req = talloc_get_type(arg, struct tevent_req);
- struct gethostbyname_state *state = tevent_req_data(req, struct gethostbyname_state);
+ struct tevent_req *req = tevent_req_callback_data(subreq,
+ struct tevent_req);
+ struct gethostbyname_state *state = tevent_req_data(req,
+ struct gethostbyname_state);
+ errno_t ret;
- if (state->retrying == 0 && status == ARES_EDESTRUCTION) {
- state->retrying = 1;
- ares_gethostbyname(state->resolv_ctx->channel, state->name,
- state->family, resolv_gethostbyname_next_done, req);
- return;
+ switch(state->db[state->dbi]) {
+ case DB_FILES:
+ ret = resolv_gethostbyname_files_recv(subreq, state,
+ &state->status,
+ &state->rhostent);
+ /* files is synchronous, there can be no timeouts */
+ state->timeouts = 0;
+ break;
+ case DB_DNS:
+ ret = resolv_gethostbyname_dns_recv(subreq, state,
+ &state->status, &state->timeouts,
+ &state->rhostent);
+ break;
+ default:
+ DEBUG(1, ("Invalid hosts database\n"));
+ tevent_req_error(req, EINVAL);
+ return;
}
- unschedule_timeout_watcher(state->resolv_ctx);
+ talloc_zfree(subreq);
- if (hostent != NULL) {
- state->hostent = resolv_copy_hostent(req, hostent);
- if (state->hostent == NULL) {
- tevent_req_error(req, ENOMEM);
+ if (ret == ENOENT) {
+ ret = resolv_gethostbyname_next(state);
+ if (ret == EOK) {
+ ret = resolv_gethostbyname_step(req);
+ if (ret != EOK) {
+ tevent_req_error(req, ret);
+ }
return;
}
- } else {
- state->hostent = NULL;
- }
- state->status = status;
- state->timeouts = timeouts;
- if (status != ARES_SUCCESS) {
- tevent_req_error(req, return_code(status));
+ /* No more databases and/or address families */
+ tevent_req_error(req, ENOENT);
+ return;
}
- else {
- tevent_req_done(req);
+
+ if (ret != EOK) {
+ DEBUG(2, ("querying hosts database failed [%d]: %s\n",
+ ret, strerror(ret)));
+ tevent_req_error(req, ret);
+ return;
}
+
+ tevent_req_done(req);
}
int
resolv_gethostbyname_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
int *status, int *timeouts,
- struct hostent **hostent)
+ struct resolv_hostent **rhostent)
{
struct gethostbyname_state *state = tevent_req_data(req, struct gethostbyname_state);
@@ -1156,8 +1255,8 @@ resolv_gethostbyname_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
if (timeouts) {
*timeouts = state->timeouts;
}
- if (hostent) {
- *hostent = talloc_steal(mem_ctx, state->hostent);
+ if (rhostent) {
+ *rhostent = talloc_steal(mem_ctx, state->rhostent);
}
TEVENT_REQ_RETURN_ON_ERROR(req);
@@ -1166,7 +1265,7 @@ resolv_gethostbyname_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
}
char *
-resolv_get_string_address(TALLOC_CTX *mem_ctx, struct hostent *hostent)
+resolv_get_string_address(TALLOC_CTX *mem_ctx, struct resolv_hostent *hostent)
{
char *address;
@@ -1179,7 +1278,7 @@ resolv_get_string_address(TALLOC_CTX *mem_ctx, struct hostent *hostent)
}
errno = 0;
- if (inet_ntop(hostent->h_addrtype, hostent->h_addr_list[0],
+ if (inet_ntop(hostent->family, hostent->addr_list[0]->ipaddr,
address, 128) == NULL) {
DEBUG(1, ("inet_ntop failed [%d][%s].\n", errno, strerror(errno)));
talloc_free(address);
@@ -1189,29 +1288,6 @@ resolv_get_string_address(TALLOC_CTX *mem_ctx, struct hostent *hostent)
return address;
}
-static void
-ares_gethostbyname_wakeup(struct tevent_req *subreq)
-{
- struct tevent_req *req = tevent_req_callback_data(subreq,
- struct tevent_req);
- struct gethostbyname_state *state = tevent_req_data(req,
- struct gethostbyname_state);
-
- if (!tevent_wakeup_recv(subreq)) {
- return;
- }
- talloc_zfree(subreq);
-
- if (state->resolv_ctx->channel == NULL) {
- DEBUG(1, ("Invalid ares channel - this is likely a bug\n"));
- tevent_req_error(req, EIO);
- return;
- }
-
- ares_gethostbyname(state->resolv_ctx->channel, state->name,
- state->family, resolv_gethostbyname_done, req);
-}
-
/*
* A simple helper function that will take an array of struct ares_srv_reply that
* was allocated by malloc() in c-ares and copies it using talloc. The old one
diff --git a/src/resolv/async_resolv.h b/src/resolv/async_resolv.h
index 00e1bdfb..907865f7 100644
--- a/src/resolv/async_resolv.h
+++ b/src/resolv/async_resolv.h
@@ -57,6 +57,29 @@ void resolv_reread_configuration(void);
const char *resolv_strerror(int ares_code);
+struct resolv_hostent *
+resolv_copy_hostent(TALLOC_CTX *mem_ctx, struct hostent *src);
+
+struct resolv_hostent *
+resolv_copy_hostent_ares(TALLOC_CTX *mem_ctx, struct hostent *src,
+ int family, void *ares_ttl_data,
+ int num_ares_ttl_data);
+
+/** Get host by name **/
+enum host_database {
+ DB_FILES,
+ DB_DNS,
+
+ DB_SENTINEL
+};
+
+enum restrict_family {
+ IPV4_ONLY,
+ IPV4_FIRST,
+ IPV6_ONLY,
+ IPV6_FIRST
+};
+
/* If resolv_hostent->family is AF_INET, then ipaddr points to
* struct in_addr, else if family is AF_INET6, ipaddr points to
* struct in6_addr
@@ -74,39 +97,22 @@ struct resolv_hostent {
struct resolv_addr **addr_list; /* list of addresses */
};
-struct resolv_hostent *
-resolv_copy_hostent2(TALLOC_CTX *mem_ctx, struct hostent *src);
-
-struct resolv_hostent *
-resolv_copy_hostent_ares(TALLOC_CTX *mem_ctx, struct hostent *src,
- int family, void *ares_ttl_data,
- int num_ares_ttl_data);
-
-struct hostent *resolv_copy_hostent(TALLOC_CTX *mem_ctx,
- struct hostent *src);
-
-/** Get host by name **/
-enum restrict_family {
- IPV4_ONLY,
- IPV4_FIRST,
- IPV6_ONLY,
- IPV6_FIRST
-};
+/* The default database order */
+extern enum host_database default_host_dbs[];
struct tevent_req *resolv_gethostbyname_send(TALLOC_CTX *mem_ctx,
struct tevent_context *ev,
struct resolv_ctx *ctx,
const char *name,
- enum restrict_family family_order);
+ enum restrict_family family_order,
+ enum host_database *db);
-int resolv_gethostbyname_recv(struct tevent_req *req,
- TALLOC_CTX *mem_ctx,
- int *status,
- int *timeouts,
- struct hostent **hostent);
+int resolv_gethostbyname_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
+ int *status, int *timeouts,
+ struct resolv_hostent **rhostent);
char *
-resolv_get_string_address(TALLOC_CTX *mem_ctx, struct hostent *hostent);
+resolv_get_string_address(TALLOC_CTX *mem_ctx, struct resolv_hostent *hostent);
/** Get SRV record **/
struct tevent_req *resolv_getsrv_send(TALLOC_CTX *mem_ctx,
generated by cgit (git 2.34.1) at 2024-11-22 05:04:12 +0000