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Systemd/src/libsystemd/sd-resolve/sd-resolve.c

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/* SPDX-License-Identifier: LGPL-2.1+ */
/***
This file is part of systemd.
Copyright 2005-2008 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <errno.h>
#include <poll.h>
#include <pthread.h>
#include <resolv.h>
#include <signal.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/prctl.h>
#include <unistd.h>
#include "sd-resolve.h"
#include "alloc-util.h"
#include "dns-domain.h"
#include "fd-util.h"
#include "io-util.h"
#include "list.h"
#include "missing.h"
#include "socket-util.h"
#include "util.h"
#include "process-util.h"
#define WORKERS_MIN 1U
#define WORKERS_MAX 16U
#define QUERIES_MAX 256U
#define BUFSIZE 10240U
typedef enum {
REQUEST_ADDRINFO,
RESPONSE_ADDRINFO,
REQUEST_NAMEINFO,
RESPONSE_NAMEINFO,
REQUEST_TERMINATE,
RESPONSE_DIED
} QueryType;
enum {
REQUEST_RECV_FD,
REQUEST_SEND_FD,
RESPONSE_RECV_FD,
RESPONSE_SEND_FD,
_FD_MAX
};
struct sd_resolve {
unsigned n_ref;
bool dead:1;
pid_t original_pid;
int fds[_FD_MAX];
pthread_t workers[WORKERS_MAX];
unsigned n_valid_workers;
unsigned current_id;
sd_resolve_query* query_array[QUERIES_MAX];
unsigned n_queries, n_done, n_outstanding;
sd_event_source *event_source;
sd_event *event;
sd_resolve_query *current;
sd_resolve **default_resolve_ptr;
pid_t tid;
LIST_HEAD(sd_resolve_query, queries);
};
struct sd_resolve_query {
unsigned n_ref;
sd_resolve *resolve;
QueryType type:4;
bool done:1;
bool floating:1;
unsigned id;
int ret;
int _errno;
int _h_errno;
struct addrinfo *addrinfo;
char *serv, *host;
union {
sd_resolve_getaddrinfo_handler_t getaddrinfo_handler;
sd_resolve_getnameinfo_handler_t getnameinfo_handler;
};
void *userdata;
LIST_FIELDS(sd_resolve_query, queries);
};
typedef struct RHeader {
QueryType type;
unsigned id;
size_t length;
} RHeader;
typedef struct AddrInfoRequest {
struct RHeader header;
bool hints_valid;
int ai_flags;
int ai_family;
int ai_socktype;
int ai_protocol;
size_t node_len, service_len;
} AddrInfoRequest;
typedef struct AddrInfoResponse {
struct RHeader header;
int ret;
int _errno;
int _h_errno;
/* followed by addrinfo_serialization[] */
} AddrInfoResponse;
typedef struct AddrInfoSerialization {
int ai_flags;
int ai_family;
int ai_socktype;
int ai_protocol;
size_t ai_addrlen;
size_t canonname_len;
/* Followed by ai_addr amd ai_canonname with variable lengths */
} AddrInfoSerialization;
typedef struct NameInfoRequest {
struct RHeader header;
int flags;
socklen_t sockaddr_len;
bool gethost:1, getserv:1;
} NameInfoRequest;
typedef struct NameInfoResponse {
struct RHeader header;
size_t hostlen, servlen;
int ret;
int _errno;
int _h_errno;
} NameInfoResponse;
typedef union Packet {
RHeader rheader;
AddrInfoRequest addrinfo_request;
AddrInfoResponse addrinfo_response;
NameInfoRequest nameinfo_request;
NameInfoResponse nameinfo_response;
} Packet;
static int getaddrinfo_done(sd_resolve_query* q);
static int getnameinfo_done(sd_resolve_query *q);
static void resolve_query_disconnect(sd_resolve_query *q);
#define RESOLVE_DONT_DESTROY(resolve) \
_cleanup_(sd_resolve_unrefp) _unused_ sd_resolve *_dont_destroy_##resolve = sd_resolve_ref(resolve)
static int send_died(int out_fd) {
RHeader rh = {
.type = RESPONSE_DIED,
.length = sizeof(RHeader),
};
assert(out_fd >= 0);
if (send(out_fd, &rh, rh.length, MSG_NOSIGNAL) < 0)
return -errno;
return 0;
}
static void *serialize_addrinfo(void *p, const struct addrinfo *ai, size_t *length, size_t maxlength) {
AddrInfoSerialization s;
size_t cnl, l;
assert(p);
assert(ai);
assert(length);
assert(*length <= maxlength);
cnl = ai->ai_canonname ? strlen(ai->ai_canonname)+1 : 0;
l = sizeof(AddrInfoSerialization) + ai->ai_addrlen + cnl;
if (*length + l > maxlength)
return NULL;
s.ai_flags = ai->ai_flags;
s.ai_family = ai->ai_family;
s.ai_socktype = ai->ai_socktype;
s.ai_protocol = ai->ai_protocol;
s.ai_addrlen = ai->ai_addrlen;
s.canonname_len = cnl;
memcpy((uint8_t*) p, &s, sizeof(AddrInfoSerialization));
memcpy((uint8_t*) p + sizeof(AddrInfoSerialization), ai->ai_addr, ai->ai_addrlen);
memcpy_safe((char*) p + sizeof(AddrInfoSerialization) + ai->ai_addrlen,
ai->ai_canonname, cnl);
*length += l;
return (uint8_t*) p + l;
}
static int send_addrinfo_reply(
int out_fd,
unsigned id,
int ret,
struct addrinfo *ai,
int _errno,
int _h_errno) {
AddrInfoResponse resp = {
.header.type = RESPONSE_ADDRINFO,
.header.id = id,
.header.length = sizeof(AddrInfoResponse),
.ret = ret,
._errno = _errno,
._h_errno = _h_errno,
};
struct msghdr mh = {};
struct iovec iov[2];
union {
AddrInfoSerialization ais;
uint8_t space[BUFSIZE];
} buffer;
assert(out_fd >= 0);
if (ret == 0 && ai) {
void *p = &buffer;
struct addrinfo *k;
for (k = ai; k; k = k->ai_next) {
p = serialize_addrinfo(p, k, &resp.header.length, (uint8_t*) &buffer + BUFSIZE - (uint8_t*) p);
if (!p) {
freeaddrinfo(ai);
return -ENOBUFS;
}
}
}
if (ai)
freeaddrinfo(ai);
iov[0] = (struct iovec) { .iov_base = &resp, .iov_len = sizeof(AddrInfoResponse) };
iov[1] = (struct iovec) { .iov_base = &buffer, .iov_len = resp.header.length - sizeof(AddrInfoResponse) };
mh.msg_iov = iov;
mh.msg_iovlen = ELEMENTSOF(iov);
if (sendmsg(out_fd, &mh, MSG_NOSIGNAL) < 0)
return -errno;
return 0;
}
static int send_nameinfo_reply(
int out_fd,
unsigned id,
int ret,
const char *host,
const char *serv,
int _errno,
int _h_errno) {
NameInfoResponse resp = {
.header.type = RESPONSE_NAMEINFO,
.header.id = id,
.ret = ret,
._errno = _errno,
._h_errno = _h_errno,
};
struct msghdr mh = {};
struct iovec iov[3];
size_t hl, sl;
assert(out_fd >= 0);
sl = serv ? strlen(serv)+1 : 0;
hl = host ? strlen(host)+1 : 0;
resp.header.length = sizeof(NameInfoResponse) + hl + sl;
resp.hostlen = hl;
resp.servlen = sl;
iov[0] = (struct iovec) { .iov_base = &resp, .iov_len = sizeof(NameInfoResponse) };
iov[1] = (struct iovec) { .iov_base = (void*) host, .iov_len = hl };
iov[2] = (struct iovec) { .iov_base = (void*) serv, .iov_len = sl };
mh.msg_iov = iov;
mh.msg_iovlen = ELEMENTSOF(iov);
if (sendmsg(out_fd, &mh, MSG_NOSIGNAL) < 0)
return -errno;
return 0;
}
static int handle_request(int out_fd, const Packet *packet, size_t length) {
const RHeader *req;
assert(out_fd >= 0);
assert(packet);
req = &packet->rheader;
assert(length >= sizeof(RHeader));
assert(length == req->length);
switch (req->type) {
case REQUEST_ADDRINFO: {
const AddrInfoRequest *ai_req = &packet->addrinfo_request;
struct addrinfo hints = {}, *result = NULL;
const char *node, *service;
int ret;
assert(length >= sizeof(AddrInfoRequest));
assert(length == sizeof(AddrInfoRequest) + ai_req->node_len + ai_req->service_len);
hints.ai_flags = ai_req->ai_flags;
hints.ai_family = ai_req->ai_family;
hints.ai_socktype = ai_req->ai_socktype;
hints.ai_protocol = ai_req->ai_protocol;
node = ai_req->node_len ? (const char*) ai_req + sizeof(AddrInfoRequest) : NULL;
service = ai_req->service_len ? (const char*) ai_req + sizeof(AddrInfoRequest) + ai_req->node_len : NULL;
ret = getaddrinfo(
node, service,
ai_req->hints_valid ? &hints : NULL,
&result);
/* send_addrinfo_reply() frees result */
return send_addrinfo_reply(out_fd, req->id, ret, result, errno, h_errno);
}
case REQUEST_NAMEINFO: {
const NameInfoRequest *ni_req = &packet->nameinfo_request;
char hostbuf[NI_MAXHOST], servbuf[NI_MAXSERV];
union sockaddr_union sa;
int ret;
assert(length >= sizeof(NameInfoRequest));
assert(length == sizeof(NameInfoRequest) + ni_req->sockaddr_len);
assert(sizeof(sa) >= ni_req->sockaddr_len);
memcpy(&sa, (const uint8_t *) ni_req + sizeof(NameInfoRequest), ni_req->sockaddr_len);
ret = getnameinfo(&sa.sa, ni_req->sockaddr_len,
ni_req->gethost ? hostbuf : NULL, ni_req->gethost ? sizeof(hostbuf) : 0,
ni_req->getserv ? servbuf : NULL, ni_req->getserv ? sizeof(servbuf) : 0,
ni_req->flags);
return send_nameinfo_reply(out_fd, req->id, ret,
ret == 0 && ni_req->gethost ? hostbuf : NULL,
ret == 0 && ni_req->getserv ? servbuf : NULL,
errno, h_errno);
}
case REQUEST_TERMINATE:
/* Quit */
return -ECONNRESET;
default:
assert_not_reached("Unknown request");
}
return 0;
}
static void* thread_worker(void *p) {
sd_resolve *resolve = p;
/* Assign a pretty name to this thread */
(void) pthread_setname_np(pthread_self(), "sd-resolve");
while (!resolve->dead) {
union {
Packet packet;
uint8_t space[BUFSIZE];
} buf;
ssize_t length;
length = recv(resolve->fds[REQUEST_RECV_FD], &buf, sizeof(buf), 0);
if (length < 0) {
if (errno == EINTR)
continue;
break;
}
if (length == 0)
break;
if (resolve->dead)
break;
if (handle_request(resolve->fds[RESPONSE_SEND_FD], &buf.packet, (size_t) length) < 0)
break;
}
send_died(resolve->fds[RESPONSE_SEND_FD]);
return NULL;
}
static int start_threads(sd_resolve *resolve, unsigned extra) {
sigset_t ss, saved_ss;
unsigned n;
int r, k;
if (sigfillset(&ss) < 0)
return -errno;
/* No signals in forked off threads please. We set the mask before forking, so that the threads never exist
* with a different mask than a fully blocked one */
r = pthread_sigmask(SIG_BLOCK, &ss, &saved_ss);
if (r > 0)
return -r;
n = resolve->n_outstanding + extra;
n = CLAMP(n, WORKERS_MIN, WORKERS_MAX);
while (resolve->n_valid_workers < n) {
r = pthread_create(&resolve->workers[resolve->n_valid_workers], NULL, thread_worker, resolve);
if (r > 0) {
r = -r;
goto finish;
}
resolve->n_valid_workers++;
}
r = 0;
finish:
k = pthread_sigmask(SIG_SETMASK, &saved_ss, NULL);
if (k > 0 && r >= 0)
r = -k;
return r;
}
static bool resolve_pid_changed(sd_resolve *r) {
assert(r);
/* We don't support people creating a resolver and keeping it
* around after fork(). Let's complain. */
return r->original_pid != getpid_cached();
}
_public_ int sd_resolve_new(sd_resolve **ret) {
sd_resolve *resolve = NULL;
int i, r;
assert_return(ret, -EINVAL);
resolve = new0(sd_resolve, 1);
if (!resolve)
return -ENOMEM;
resolve->n_ref = 1;
resolve->original_pid = getpid_cached();
for (i = 0; i < _FD_MAX; i++)
resolve->fds[i] = -1;
r = socketpair(PF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, resolve->fds + REQUEST_RECV_FD);
if (r < 0) {
r = -errno;
goto fail;
}
r = socketpair(PF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, resolve->fds + RESPONSE_RECV_FD);
if (r < 0) {
r = -errno;
goto fail;
}
fd_inc_sndbuf(resolve->fds[REQUEST_SEND_FD], QUERIES_MAX * BUFSIZE);
fd_inc_rcvbuf(resolve->fds[REQUEST_RECV_FD], QUERIES_MAX * BUFSIZE);
fd_inc_sndbuf(resolve->fds[RESPONSE_SEND_FD], QUERIES_MAX * BUFSIZE);
fd_inc_rcvbuf(resolve->fds[RESPONSE_RECV_FD], QUERIES_MAX * BUFSIZE);
fd_nonblock(resolve->fds[RESPONSE_RECV_FD], true);
*ret = resolve;
return 0;
fail:
sd_resolve_unref(resolve);
return r;
}
_public_ int sd_resolve_default(sd_resolve **ret) {
static thread_local sd_resolve *default_resolve = NULL;
sd_resolve *e = NULL;
int r;
if (!ret)
return !!default_resolve;
if (default_resolve) {
*ret = sd_resolve_ref(default_resolve);
return 0;
}
r = sd_resolve_new(&e);
if (r < 0)
return r;
e->default_resolve_ptr = &default_resolve;
e->tid = gettid();
default_resolve = e;
*ret = e;
return 1;
}
_public_ int sd_resolve_get_tid(sd_resolve *resolve, pid_t *tid) {
assert_return(resolve, -EINVAL);
assert_return(tid, -EINVAL);
assert_return(!resolve_pid_changed(resolve), -ECHILD);
if (resolve->tid != 0) {
*tid = resolve->tid;
return 0;
}
if (resolve->event)
return sd_event_get_tid(resolve->event, tid);
return -ENXIO;
}
static void resolve_free(sd_resolve *resolve) {
PROTECT_ERRNO;
sd_resolve_query *q;
unsigned i;
assert(resolve);
while ((q = resolve->queries)) {
assert(q->floating);
resolve_query_disconnect(q);
sd_resolve_query_unref(q);
}
if (resolve->default_resolve_ptr)
*(resolve->default_resolve_ptr) = NULL;
resolve->dead = true;
sd_resolve_detach_event(resolve);
if (resolve->fds[REQUEST_SEND_FD] >= 0) {
RHeader req = {
.type = REQUEST_TERMINATE,
.length = sizeof(req)
};
/* Send one termination packet for each worker */
for (i = 0; i < resolve->n_valid_workers; i++)
(void) send(resolve->fds[REQUEST_SEND_FD], &req, req.length, MSG_NOSIGNAL);
}
/* Now terminate them and wait until they are gone.
If we get an error than most likely the thread already exited. */
for (i = 0; i < resolve->n_valid_workers; i++)
(void) pthread_join(resolve->workers[i], NULL);
/* Close all communication channels */
close_many(resolve->fds, _FD_MAX);
free(resolve);
}
_public_ sd_resolve* sd_resolve_ref(sd_resolve *resolve) {
assert_return(resolve, NULL);
assert(resolve->n_ref >= 1);
resolve->n_ref++;
return resolve;
}
_public_ sd_resolve* sd_resolve_unref(sd_resolve *resolve) {
if (!resolve)
return NULL;
assert(resolve->n_ref >= 1);
resolve->n_ref--;
if (resolve->n_ref <= 0)
resolve_free(resolve);
return NULL;
}
_public_ int sd_resolve_get_fd(sd_resolve *resolve) {
assert_return(resolve, -EINVAL);
assert_return(!resolve_pid_changed(resolve), -ECHILD);
return resolve->fds[RESPONSE_RECV_FD];
}
_public_ int sd_resolve_get_events(sd_resolve *resolve) {
assert_return(resolve, -EINVAL);
assert_return(!resolve_pid_changed(resolve), -ECHILD);
return resolve->n_queries > resolve->n_done ? POLLIN : 0;
}
_public_ int sd_resolve_get_timeout(sd_resolve *resolve, uint64_t *usec) {
assert_return(resolve, -EINVAL);
assert_return(usec, -EINVAL);
assert_return(!resolve_pid_changed(resolve), -ECHILD);
*usec = (uint64_t) -1;
return 0;
}
static sd_resolve_query *lookup_query(sd_resolve *resolve, unsigned id) {
sd_resolve_query *q;
assert(resolve);
q = resolve->query_array[id % QUERIES_MAX];
if (q)
if (q->id == id)
return q;
return NULL;
}
static int complete_query(sd_resolve *resolve, sd_resolve_query *q) {
int r;
assert(q);
assert(!q->done);
assert(q->resolve == resolve);
q->done = true;
resolve->n_done++;
resolve->current = sd_resolve_query_ref(q);
switch (q->type) {
case REQUEST_ADDRINFO:
r = getaddrinfo_done(q);
break;
case REQUEST_NAMEINFO:
r = getnameinfo_done(q);
break;
default:
assert_not_reached("Cannot complete unknown query type");
}
resolve->current = NULL;
if (q->floating) {
resolve_query_disconnect(q);
sd_resolve_query_unref(q);
}
sd_resolve_query_unref(q);
return r;
}
static int unserialize_addrinfo(const void **p, size_t *length, struct addrinfo **ret_ai) {
AddrInfoSerialization s;
size_t l;
struct addrinfo *ai;
assert(p);
assert(*p);
assert(ret_ai);
assert(length);
if (*length < sizeof(AddrInfoSerialization))
return -EBADMSG;
memcpy(&s, *p, sizeof(s));
l = sizeof(AddrInfoSerialization) + s.ai_addrlen + s.canonname_len;
if (*length < l)
return -EBADMSG;
ai = new0(struct addrinfo, 1);
if (!ai)
return -ENOMEM;
ai->ai_flags = s.ai_flags;
ai->ai_family = s.ai_family;
ai->ai_socktype = s.ai_socktype;
ai->ai_protocol = s.ai_protocol;
ai->ai_addrlen = s.ai_addrlen;
if (s.ai_addrlen > 0) {
ai->ai_addr = memdup((const uint8_t*) *p + sizeof(AddrInfoSerialization), s.ai_addrlen);
if (!ai->ai_addr) {
free(ai);
return -ENOMEM;
}
}
if (s.canonname_len > 0) {
ai->ai_canonname = memdup((const uint8_t*) *p + sizeof(AddrInfoSerialization) + s.ai_addrlen, s.canonname_len);
if (!ai->ai_canonname) {
free(ai->ai_addr);
free(ai);
return -ENOMEM;
}
}
*length -= l;
*ret_ai = ai;
*p = ((const uint8_t*) *p) + l;
return 0;
}
static int handle_response(sd_resolve *resolve, const Packet *packet, size_t length) {
const RHeader *resp;
sd_resolve_query *q;
int r;
assert(resolve);
resp = &packet->rheader;
assert(resp);
assert(length >= sizeof(RHeader));
assert(length == resp->length);
if (resp->type == RESPONSE_DIED) {
resolve->dead = true;
return 0;
}
assert(resolve->n_outstanding > 0);
resolve->n_outstanding--;
q = lookup_query(resolve, resp->id);
if (!q)
return 0;
switch (resp->type) {
case RESPONSE_ADDRINFO: {
const AddrInfoResponse *ai_resp = &packet->addrinfo_response;
const void *p;
size_t l;
struct addrinfo *prev = NULL;
assert(length >= sizeof(AddrInfoResponse));
assert(q->type == REQUEST_ADDRINFO);
q->ret = ai_resp->ret;
q->_errno = ai_resp->_errno;
q->_h_errno = ai_resp->_h_errno;
l = length - sizeof(AddrInfoResponse);
p = (const uint8_t*) resp + sizeof(AddrInfoResponse);
while (l > 0 && p) {
struct addrinfo *ai = NULL;
r = unserialize_addrinfo(&p, &l, &ai);
if (r < 0) {
q->ret = EAI_SYSTEM;
q->_errno = -r;
q->_h_errno = 0;
freeaddrinfo(q->addrinfo);
q->addrinfo = NULL;
break;
}
if (prev)
prev->ai_next = ai;
else
q->addrinfo = ai;
prev = ai;
}
return complete_query(resolve, q);
}
case RESPONSE_NAMEINFO: {
const NameInfoResponse *ni_resp = &packet->nameinfo_response;
assert(length >= sizeof(NameInfoResponse));
assert(q->type == REQUEST_NAMEINFO);
if (ni_resp->hostlen > DNS_HOSTNAME_MAX ||
ni_resp->servlen > DNS_HOSTNAME_MAX ||
sizeof(NameInfoResponse) + ni_resp->hostlen + ni_resp->servlen > length + 2) {
q->ret = EAI_SYSTEM;
q->_errno = -EIO;
q->_h_errno = 0;
} else {
q->ret = ni_resp->ret;
q->_errno = ni_resp->_errno;
q->_h_errno = ni_resp->_h_errno;
if (ni_resp->hostlen > 0) {
q->host = strndup((const char*) ni_resp + sizeof(NameInfoResponse),
ni_resp->hostlen-1);
if (!q->host) {
q->ret = EAI_MEMORY;
q->_errno = ENOMEM;
q->_h_errno = 0;
}
}
if (ni_resp->servlen > 0) {
q->serv = strndup((const char*) ni_resp + sizeof(NameInfoResponse) + ni_resp->hostlen,
ni_resp->servlen-1);
if (!q->serv) {
q->ret = EAI_MEMORY;
q->_errno = ENOMEM;
q->_h_errno = 0;
}
}
}
return complete_query(resolve, q);
}
default:
return 0;
}
}
_public_ int sd_resolve_process(sd_resolve *resolve) {
RESOLVE_DONT_DESTROY(resolve);
union {
Packet packet;
uint8_t space[BUFSIZE];
} buf;
ssize_t l;
int r;
assert_return(resolve, -EINVAL);
assert_return(!resolve_pid_changed(resolve), -ECHILD);
/* We don't allow recursively invoking sd_resolve_process(). */
assert_return(!resolve->current, -EBUSY);
l = recv(resolve->fds[RESPONSE_RECV_FD], &buf, sizeof(buf), 0);
if (l < 0) {
if (errno == EAGAIN)
return 0;
return -errno;
}
if (l == 0)
return -ECONNREFUSED;
r = handle_response(resolve, &buf.packet, (size_t) l);
if (r < 0)
return r;
return 1;
}
_public_ int sd_resolve_wait(sd_resolve *resolve, uint64_t timeout_usec) {
int r;
assert_return(resolve, -EINVAL);
assert_return(!resolve_pid_changed(resolve), -ECHILD);
if (resolve->n_done >= resolve->n_queries)
return 0;
do {
r = fd_wait_for_event(resolve->fds[RESPONSE_RECV_FD], POLLIN, timeout_usec);
} while (r == -EINTR);
if (r < 0)
return r;
if (r == 0)
return -ETIMEDOUT;
return sd_resolve_process(resolve);
}
static int alloc_query(sd_resolve *resolve, bool floating, sd_resolve_query **_q) {
sd_resolve_query *q;
int r;
assert(resolve);
assert(_q);
if (resolve->n_queries >= QUERIES_MAX)
return -ENOBUFS;
r = start_threads(resolve, 1);
if (r < 0)
return r;
while (resolve->query_array[resolve->current_id % QUERIES_MAX])
resolve->current_id++;
q = resolve->query_array[resolve->current_id % QUERIES_MAX] = new0(sd_resolve_query, 1);
if (!q)
return -ENOMEM;
q->n_ref = 1;
q->resolve = resolve;
q->floating = floating;
q->id = resolve->current_id++;
if (!floating)
sd_resolve_ref(resolve);
LIST_PREPEND(queries, resolve->queries, q);
resolve->n_queries++;
*_q = q;
return 0;
}
_public_ int sd_resolve_getaddrinfo(
sd_resolve *resolve,
sd_resolve_query **_q,
const char *node, const char *service,
const struct addrinfo *hints,
sd_resolve_getaddrinfo_handler_t callback, void *userdata) {
AddrInfoRequest req = {};
struct msghdr mh = {};
struct iovec iov[3];
sd_resolve_query *q;
int r;
assert_return(resolve, -EINVAL);
assert_return(node || service, -EINVAL);
assert_return(callback, -EINVAL);
assert_return(!resolve_pid_changed(resolve), -ECHILD);
r = alloc_query(resolve, !_q, &q);
if (r < 0)
return r;
q->type = REQUEST_ADDRINFO;
q->getaddrinfo_handler = callback;
q->userdata = userdata;
req.node_len = node ? strlen(node)+1 : 0;
req.service_len = service ? strlen(service)+1 : 0;
req.header.id = q->id;
req.header.type = REQUEST_ADDRINFO;
req.header.length = sizeof(AddrInfoRequest) + req.node_len + req.service_len;
if (hints) {
req.hints_valid = true;
req.ai_flags = hints->ai_flags;
req.ai_family = hints->ai_family;
req.ai_socktype = hints->ai_socktype;
req.ai_protocol = hints->ai_protocol;
}
iov[mh.msg_iovlen++] = (struct iovec) { .iov_base = &req, .iov_len = sizeof(AddrInfoRequest) };
if (node)
iov[mh.msg_iovlen++] = (struct iovec) { .iov_base = (void*) node, .iov_len = req.node_len };
if (service)
iov[mh.msg_iovlen++] = (struct iovec) { .iov_base = (void*) service, .iov_len = req.service_len };
mh.msg_iov = iov;
if (sendmsg(resolve->fds[REQUEST_SEND_FD], &mh, MSG_NOSIGNAL) < 0) {
sd_resolve_query_unref(q);
return -errno;
}
resolve->n_outstanding++;
if (_q)
*_q = q;
return 0;
}
static int getaddrinfo_done(sd_resolve_query* q) {
assert(q);
assert(q->done);
assert(q->getaddrinfo_handler);
errno = q->_errno;
h_errno = q->_h_errno;
return q->getaddrinfo_handler(q, q->ret, q->addrinfo, q->userdata);
}
_public_ int sd_resolve_getnameinfo(
sd_resolve *resolve,
sd_resolve_query**_q,
const struct sockaddr *sa, socklen_t salen,
int flags,
uint64_t get,
sd_resolve_getnameinfo_handler_t callback,
void *userdata) {
NameInfoRequest req = {};
struct msghdr mh = {};
struct iovec iov[2];
sd_resolve_query *q;
int r;
assert_return(resolve, -EINVAL);
assert_return(sa, -EINVAL);
assert_return(salen >= sizeof(struct sockaddr), -EINVAL);
assert_return(salen <= sizeof(union sockaddr_union), -EINVAL);
assert_return((get & ~SD_RESOLVE_GET_BOTH) == 0, -EINVAL);
assert_return(callback, -EINVAL);
assert_return(!resolve_pid_changed(resolve), -ECHILD);
r = alloc_query(resolve, !_q, &q);
if (r < 0)
return r;
q->type = REQUEST_NAMEINFO;
q->getnameinfo_handler = callback;
q->userdata = userdata;
req.header.id = q->id;
req.header.type = REQUEST_NAMEINFO;
req.header.length = sizeof(NameInfoRequest) + salen;
req.flags = flags;
req.sockaddr_len = salen;
req.gethost = !!(get & SD_RESOLVE_GET_HOST);
req.getserv = !!(get & SD_RESOLVE_GET_SERVICE);
iov[0] = (struct iovec) { .iov_base = &req, .iov_len = sizeof(NameInfoRequest) };
iov[1] = (struct iovec) { .iov_base = (void*) sa, .iov_len = salen };
mh.msg_iov = iov;
mh.msg_iovlen = 2;
if (sendmsg(resolve->fds[REQUEST_SEND_FD], &mh, MSG_NOSIGNAL) < 0) {
sd_resolve_query_unref(q);
return -errno;
}
resolve->n_outstanding++;
if (_q)
*_q = q;
return 0;
}
static int getnameinfo_done(sd_resolve_query *q) {
assert(q);
assert(q->done);
assert(q->getnameinfo_handler);
errno = q->_errno;
h_errno= q->_h_errno;
return q->getnameinfo_handler(q, q->ret, q->host, q->serv, q->userdata);
}
_public_ sd_resolve_query* sd_resolve_query_ref(sd_resolve_query *q) {
assert_return(q, NULL);
assert(q->n_ref >= 1);
q->n_ref++;
return q;
}
static void resolve_freeaddrinfo(struct addrinfo *ai) {
while (ai) {
struct addrinfo *next = ai->ai_next;
free(ai->ai_addr);
free(ai->ai_canonname);
free(ai);
ai = next;
}
}
static void resolve_query_disconnect(sd_resolve_query *q) {
sd_resolve *resolve;
unsigned i;
assert(q);
if (!q->resolve)
return;
resolve = q->resolve;
assert(resolve->n_queries > 0);
if (q->done) {
assert(resolve->n_done > 0);
resolve->n_done--;
}
i = q->id % QUERIES_MAX;
assert(resolve->query_array[i] == q);
resolve->query_array[i] = NULL;
LIST_REMOVE(queries, resolve->queries, q);
resolve->n_queries--;
q->resolve = NULL;
if (!q->floating)
sd_resolve_unref(resolve);
}
static void resolve_query_free(sd_resolve_query *q) {
assert(q);
resolve_query_disconnect(q);
resolve_freeaddrinfo(q->addrinfo);
free(q->host);
free(q->serv);
free(q);
}
_public_ sd_resolve_query* sd_resolve_query_unref(sd_resolve_query* q) {
if (!q)
return NULL;
assert(q->n_ref >= 1);
q->n_ref--;
if (q->n_ref <= 0)
resolve_query_free(q);
return NULL;
}
_public_ int sd_resolve_query_is_done(sd_resolve_query *q) {
assert_return(q, -EINVAL);
assert_return(!resolve_pid_changed(q->resolve), -ECHILD);
return q->done;
}
_public_ void* sd_resolve_query_set_userdata(sd_resolve_query *q, void *userdata) {
void *ret;
assert_return(q, NULL);
assert_return(!resolve_pid_changed(q->resolve), NULL);
ret = q->userdata;
q->userdata = userdata;
return ret;
}
_public_ void* sd_resolve_query_get_userdata(sd_resolve_query *q) {
assert_return(q, NULL);
assert_return(!resolve_pid_changed(q->resolve), NULL);
return q->userdata;
}
_public_ sd_resolve *sd_resolve_query_get_resolve(sd_resolve_query *q) {
assert_return(q, NULL);
assert_return(!resolve_pid_changed(q->resolve), NULL);
return q->resolve;
}
static int io_callback(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
sd_resolve *resolve = userdata;
int r;
assert(resolve);
r = sd_resolve_process(resolve);
if (r < 0)
return r;
return 1;
}
_public_ int sd_resolve_attach_event(sd_resolve *resolve, sd_event *event, int64_t priority) {
int r;
assert_return(resolve, -EINVAL);
assert_return(!resolve->event, -EBUSY);
assert(!resolve->event_source);
if (event)
resolve->event = sd_event_ref(event);
else {
r = sd_event_default(&resolve->event);
if (r < 0)
return r;
}
r = sd_event_add_io(resolve->event, &resolve->event_source, resolve->fds[RESPONSE_RECV_FD], POLLIN, io_callback, resolve);
if (r < 0)
goto fail;
r = sd_event_source_set_priority(resolve->event_source, priority);
if (r < 0)
goto fail;
return 0;
fail:
sd_resolve_detach_event(resolve);
return r;
}
_public_ int sd_resolve_detach_event(sd_resolve *resolve) {
assert_return(resolve, -EINVAL);
if (!resolve->event)
return 0;
if (resolve->event_source) {
sd_event_source_set_enabled(resolve->event_source, SD_EVENT_OFF);
resolve->event_source = sd_event_source_unref(resolve->event_source);
}
resolve->event = sd_event_unref(resolve->event);
return 1;
}
_public_ sd_event *sd_resolve_get_event(sd_resolve *resolve) {
assert_return(resolve, NULL);
return resolve->event;
}
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