#include <signal.h>

#include <unistd.h>

#include <stdio.h>

#include <string.h>

#include <stdlib.h>

#include <errno.h>

#include <resolv.h>

#include <stdint.h>

#include <pthread.h>

#include <sys/prctl.h>

#include <poll.h>

#include "util.h"

#include "list.h"

#include "socket-util.h"

#include "missing.h"

#include "resolve-util.h"

#include "sd-resolve.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_RES_QUERY,

REQUEST_RES_SEARCH,

RESPONSE_RES,

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;

unsigned char *answer;

union {

sd_resolve_getaddrinfo_handler_t getaddrinfo_handler;

sd_resolve_getnameinfo_handler_t getnameinfo_handler;

sd_resolve_res_handler_t res_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 struct ResRequest {

struct RHeader header;

int class;

int type;

size_t dname_len;

} ResRequest;

typedef struct ResResponse {

struct RHeader header;

int ret;

int _errno;

int _h_errno;

} ResResponse;

typedef union Packet {

RHeader rheader;

AddrInfoRequest addrinfo_request;

AddrInfoResponse addrinfo_response;

NameInfoRequest nameinfo_request;

NameInfoResponse nameinfo_response;

ResRequest res_request;

ResResponse res_response;

} Packet;

static int getaddrinfo_done(sd_resolve_query* q);

static int getnameinfo_done(sd_resolve_query *q);

static int res_query_done(sd_resolve_query* q);

static void resolve_query_disconnect(sd_resolve_query *q);

#define RESOLVE_DONT_DESTROY(resolve) \

_cleanup_resolve_unref_ _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);

if (ai->ai_canonname)

memcpy((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 send_res_reply(int out_fd, unsigned id, const unsigned char *answer, int ret, int _errno, int _h_errno) {

ResResponse resp = {

.header.type = RESPONSE_RES,

.header.id = id,

.ret = ret,

._errno = _errno,

._h_errno = _h_errno,

};

struct msghdr mh = {};

struct iovec iov[2];

size_t l;

assert(out_fd >= 0);

l = ret > 0 ? (size_t) ret : 0;

resp.header.length = sizeof(ResResponse) + l;

iov[0] = (struct iovec) { .iov_base = &resp, .iov_len = sizeof(ResResponse) };

iov[1] = (struct iovec) { .iov_base = (void*) answer, .iov_len = l };

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_RES_QUERY:

case REQUEST_RES_SEARCH: {

const ResRequest *res_req = &packet->res_request;

union {

HEADER header;

uint8_t space[BUFSIZE];

} answer;

const char *dname;

int ret;

assert(length >= sizeof(ResRequest));

assert(length == sizeof(ResRequest) + res_req->dname_len);

dname = (const char *) res_req + sizeof(ResRequest);

if (req->type == REQUEST_RES_QUERY)

ret = res_query(dname, res_req->class, res_req->type, (unsigned char *) &answer, BUFSIZE);

else

ret = res_search(dname, res_req->class, res_req->type, (unsigned char *) &answer, BUFSIZE);

return send_res_reply(out_fd, req->id, (unsigned char *) &answer, ret, 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;

sigset_t fullset;

/* No signals in this thread please */

assert_se(sigfillset(&fullset) == 0);

assert_se(pthread_sigmask(SIG_BLOCK, &fullset, NULL) == 0);

/* Assign a pretty name to this thread */

prctl(PR_SET_NAME, (unsigned long) "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) {

unsigned n;

int 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)

return -r;

resolve->n_valid_workers ++;

}

return 0;

}

static bool resolve_pid_changed(sd_resolve *r) {

assert(r);

/* We don't support people creating a resolver and keeping it

return r->original_pid != getpid();

}

_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();

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. */

for (i = 0; i < resolve->n_valid_workers; i++) {

for (;;) {

if (pthread_join(resolve->workers[i], NULL) != EINTR)

break;

}

}

/* Close all communication channels */

for (i = 0; i < _FD_MAX; i++)

safe_close(resolve->fds[i]);

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;

case REQUEST_RES_QUERY:

case REQUEST_RES_SEARCH:

r = res_query_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);

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);

}

case RESPONSE_RES: {

const ResResponse *res_resp = &packet->res_response;

assert(length >= sizeof(ResResponse));

assert(q->type == REQUEST_RES_QUERY || q->type == REQUEST_RES_SEARCH);

q->ret = res_resp->ret;

q->_errno = res_resp->_errno;

q->_h_errno = res_resp->_h_errno;

if (res_resp->ret >= 0) {

q->answer = memdup((const char *)resp + sizeof(ResResponse), res_resp->ret);

if (!q->answer) {

q->ret = -1;

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;

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);

}

static int resolve_res(

sd_resolve *resolve,

sd_resolve_query **_q,

QueryType qtype,

const char *dname,

int class, int type,

sd_resolve_res_handler_t callback, void *userdata) {

struct msghdr mh = {};

struct iovec iov[2];

ResRequest req = {};

sd_resolve_query *q;

int r;

assert_return(resolve, -EINVAL);

assert_return(dname, -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 = qtype;

q->res_handler = callback;

q->userdata = userdata;

req.dname_len = strlen(dname) + 1;

req.class = class;

req.type = type;

req.header.id = q->id;

req.header.type = qtype;

req.header.length = sizeof(ResRequest) + req.dname_len;

iov[0] = (struct iovec) { .iov_base = &req, .iov_len = sizeof(ResRequest) };

iov[1] = (struct iovec) { .iov_base = (void*) dname, .iov_len = req.dname_len };

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;

}

_public_ int sd_resolve_res_query(sd_resolve *resolve, sd_resolve_query** q, const char *dname, int class, int type, sd_resolve_res_handler_t callback, void *userdata) {

return resolve_res(resolve, q, REQUEST_RES_QUERY, dname, class, type, callback, userdata);

}

_public_ int sd_resolve_res_search(sd_resolve *resolve, sd_resolve_query** q, const char *dname, int class, int type, sd_resolve_res_handler_t callback, void *userdata) {

return resolve_res(resolve, q, REQUEST_RES_SEARCH, dname, class, type, callback, userdata);

}

static int res_query_done(sd_resolve_query* q) {

assert(q);

assert(q->done);

assert(q->res_handler);

errno = q->_errno;

h_errno = q->_h_errno;

return q->res_handler(q, q->ret, q->answer, 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->answer);

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, int 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;

}