sock: Introduce xmpp_sock_t abstraction
libstrophe uses non-blocking sockets and the connect() syscall may return before a TCP connection is established. This doesn't allow to catch all possible errors synchronously and some of the errors are handled in the event handler. In a scenario with multiple SRV records and/or multiple IP addresses resolution, we need to repeat connection attempt on a failure. xmpp_sock_t resolves the above problem. It keeps resolved records and addresses to repeat connect attempt asynchronously.
This commit is contained in:
Dmitry Podgorny
207
src/sock.c
207
src/sock.c
@@ -24,6 +24,7 @@
|
||||
#include <iphlpapi.h>
|
||||
#include <mstcpip.h> /* tcp_keepalive */
|
||||
#else
|
||||
#include <arpa/inet.h>
|
||||
#include <errno.h>
|
||||
#include <unistd.h>
|
||||
#include <sys/socket.h>
|
||||
@@ -34,6 +35,18 @@
|
||||
#endif
|
||||
|
||||
#include "common.h"
|
||||
#include "resolver.h"
|
||||
|
||||
struct _xmpp_sock_t {
|
||||
xmpp_ctx_t *ctx;
|
||||
xmpp_conn_t *conn;
|
||||
struct addrinfo *ainfo_list;
|
||||
struct addrinfo *ainfo_cur;
|
||||
resolver_srv_rr_t *srv_rr_list;
|
||||
resolver_srv_rr_t *srv_rr_cur;
|
||||
const char *host;
|
||||
unsigned short port;
|
||||
};
|
||||
|
||||
void sock_initialize(void)
|
||||
{
|
||||
@@ -68,50 +81,164 @@ static int _in_progress(int error)
|
||||
#endif
|
||||
}
|
||||
|
||||
sock_t sock_connect(xmpp_conn_t *conn, const char *host, unsigned short port)
|
||||
static void sock_getaddrinfo(xmpp_sock_t *xsock)
|
||||
{
|
||||
sock_t sock;
|
||||
char service[6];
|
||||
struct addrinfo *res, *ainfo, hints;
|
||||
int err;
|
||||
struct addrinfo hints;
|
||||
int rc;
|
||||
|
||||
strophe_snprintf(service, 6, "%u", port);
|
||||
|
||||
memset(&hints, 0, sizeof(struct addrinfo));
|
||||
hints.ai_family = AF_UNSPEC;
|
||||
#ifdef AI_ADDRCONFIG
|
||||
hints.ai_flags = AI_ADDRCONFIG;
|
||||
#endif /* AI_ADDRCONFIG */
|
||||
hints.ai_protocol = IPPROTO_TCP;
|
||||
hints.ai_socktype = SOCK_STREAM;
|
||||
|
||||
err = getaddrinfo(host, service, &hints, &res);
|
||||
if (err != 0)
|
||||
return -1;
|
||||
|
||||
for (ainfo = res; ainfo != NULL; ainfo = ainfo->ai_next) {
|
||||
sock = socket(ainfo->ai_family, ainfo->ai_socktype, ainfo->ai_protocol);
|
||||
if (sock < 0)
|
||||
continue;
|
||||
|
||||
if (conn->sockopt_cb != NULL)
|
||||
err = (conn->sockopt_cb)(conn, &sock);
|
||||
|
||||
if (err != 0) {
|
||||
sock_close(sock);
|
||||
continue;
|
||||
}
|
||||
|
||||
err = sock_set_nonblocking(sock);
|
||||
if (err == 0) {
|
||||
err = connect(sock, ainfo->ai_addr, ainfo->ai_addrlen);
|
||||
if (err == 0 || _in_progress(sock_error()))
|
||||
break;
|
||||
}
|
||||
sock_close(sock);
|
||||
if (xsock->ainfo_list) {
|
||||
freeaddrinfo(xsock->ainfo_list);
|
||||
xsock->ainfo_list = NULL;
|
||||
}
|
||||
freeaddrinfo(res);
|
||||
sock = ainfo == NULL ? -1 : sock;
|
||||
|
||||
if (xsock->srv_rr_cur) {
|
||||
/* Cache host and port for debug logs. */
|
||||
xsock->host = xsock->srv_rr_cur->target;
|
||||
xsock->port = xsock->srv_rr_cur->port;
|
||||
|
||||
strophe_snprintf(service, 6, "%u", xsock->srv_rr_cur->port);
|
||||
memset(&hints, 0, sizeof(struct addrinfo));
|
||||
hints.ai_family = AF_UNSPEC;
|
||||
#ifdef AI_ADDRCONFIG
|
||||
hints.ai_flags = AI_ADDRCONFIG;
|
||||
#endif /* AI_ADDRCONFIG */
|
||||
hints.ai_protocol = IPPROTO_TCP;
|
||||
hints.ai_socktype = SOCK_STREAM;
|
||||
|
||||
rc = getaddrinfo(xsock->srv_rr_cur->target, service, &hints,
|
||||
&xsock->ainfo_list);
|
||||
if (rc != 0) {
|
||||
strophe_debug(xsock->ctx, "sock", "getaddrinfo() failed with %d",
|
||||
rc);
|
||||
xsock->ainfo_list = NULL;
|
||||
}
|
||||
}
|
||||
|
||||
xsock->ainfo_cur = xsock->ainfo_list;
|
||||
}
|
||||
|
||||
xmpp_sock_t *sock_new(xmpp_conn_t *conn,
|
||||
const char *domain,
|
||||
const char *host,
|
||||
unsigned short port)
|
||||
{
|
||||
xmpp_ctx_t *ctx = conn->ctx;
|
||||
xmpp_sock_t *xsock;
|
||||
int found = XMPP_DOMAIN_NOT_FOUND;
|
||||
|
||||
xsock = strophe_alloc(ctx, sizeof(*xsock));
|
||||
if (!xsock) {
|
||||
return NULL;
|
||||
}
|
||||
|
||||
xsock->ctx = ctx;
|
||||
xsock->conn = conn;
|
||||
xsock->host = NULL;
|
||||
xsock->port = 0;
|
||||
|
||||
if (!host) {
|
||||
found = resolver_srv_lookup(ctx, "xmpp-client", "tcp", domain,
|
||||
&xsock->srv_rr_list);
|
||||
if (XMPP_DOMAIN_NOT_FOUND == found)
|
||||
strophe_debug(ctx, "sock",
|
||||
"SRV lookup failed, connecting via domain.");
|
||||
}
|
||||
if (XMPP_DOMAIN_NOT_FOUND == found) {
|
||||
/* Resolution failed or the host is provided explicitly. */
|
||||
xsock->srv_rr_list =
|
||||
resolver_srv_rr_new(ctx, host ? host : domain, port, 0, 0);
|
||||
}
|
||||
xsock->srv_rr_cur = xsock->srv_rr_list;
|
||||
|
||||
xsock->ainfo_list = NULL;
|
||||
sock_getaddrinfo(xsock);
|
||||
if (xsock->srv_rr_cur)
|
||||
xsock->srv_rr_cur = xsock->srv_rr_cur->next;
|
||||
|
||||
return xsock;
|
||||
}
|
||||
|
||||
void sock_free(xmpp_sock_t *xsock)
|
||||
{
|
||||
if (!xsock)
|
||||
return;
|
||||
|
||||
if (xsock->ainfo_list)
|
||||
freeaddrinfo(xsock->ainfo_list);
|
||||
if (xsock->srv_rr_list)
|
||||
resolver_srv_free(xsock->ctx, xsock->srv_rr_list);
|
||||
strophe_free(xsock->ctx, xsock);
|
||||
}
|
||||
|
||||
static const char *_sockaddr2str(struct sockaddr *sa, char *buf, size_t buflen)
|
||||
{
|
||||
buf[0] = '\0';
|
||||
|
||||
switch (sa->sa_family) {
|
||||
case AF_INET:
|
||||
inet_ntop(AF_INET, &((struct sockaddr_in *)sa)->sin_addr, buf, buflen);
|
||||
break;
|
||||
case AF_INET6:
|
||||
inet_ntop(AF_INET6, &((struct sockaddr_in6 *)sa)->sin6_addr, buf,
|
||||
buflen);
|
||||
break;
|
||||
default:
|
||||
strophe_snprintf(buf, buflen, "<Unknown>");
|
||||
}
|
||||
return buf;
|
||||
}
|
||||
|
||||
sock_t sock_connect(xmpp_sock_t *xsock)
|
||||
{
|
||||
struct addrinfo *ainfo;
|
||||
sock_t sock;
|
||||
int rc = 0;
|
||||
char buf[64];
|
||||
|
||||
do {
|
||||
if (!xsock->ainfo_cur) {
|
||||
sock_getaddrinfo(xsock);
|
||||
if (xsock->srv_rr_cur)
|
||||
xsock->srv_rr_cur = xsock->srv_rr_cur->next;
|
||||
}
|
||||
if (!xsock->ainfo_cur) {
|
||||
/* We tried all available addresses. */
|
||||
return INVALID_SOCKET;
|
||||
}
|
||||
|
||||
ainfo = xsock->ainfo_cur;
|
||||
strophe_debug(xsock->ctx, "sock", "Connecting to %s:%u via %s",
|
||||
xsock->host, xsock->port,
|
||||
_sockaddr2str(ainfo->ai_addr, buf, sizeof(buf)));
|
||||
|
||||
sock = socket(ainfo->ai_family, ainfo->ai_socktype, ainfo->ai_protocol);
|
||||
if (sock != INVALID_SOCKET) {
|
||||
if (xsock->conn->sockopt_cb) {
|
||||
/* Don't allow user to overwrite sockfd value. */
|
||||
sock_t sock_copy = sock;
|
||||
rc = xsock->conn->sockopt_cb(xsock->conn, &sock_copy);
|
||||
if (rc != 0) {
|
||||
strophe_debug(xsock->ctx, "sock",
|
||||
"User's setsockopt callback"
|
||||
"failed with %d (errno=%d)",
|
||||
rc, errno);
|
||||
}
|
||||
}
|
||||
if (rc == 0)
|
||||
rc = sock_set_nonblocking(sock);
|
||||
if (rc == 0)
|
||||
rc = connect(sock, ainfo->ai_addr, ainfo->ai_addrlen);
|
||||
/* Assume only connect() can cause "in progress" error. */
|
||||
if (rc != 0 && !_in_progress(sock_error())) {
|
||||
sock_close(sock);
|
||||
sock = INVALID_SOCKET;
|
||||
}
|
||||
}
|
||||
strophe_debug(xsock->ctx, "sock", "sock_connect() result %d", sock);
|
||||
|
||||
xsock->ainfo_cur = xsock->ainfo_cur->ai_next;
|
||||
} while (sock == INVALID_SOCKET);
|
||||
|
||||
return sock;
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user