/* Licensed under BSD-MIT - see LICENSE file for details */
#include <ccan/net/net.h>
+#include <ccan/noerr/noerr.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <poll.h>
#include <errno.h>
#include <stdbool.h>
#include <netinet/in.h>
+#include <assert.h>
struct addrinfo *net_client_lookup(const char *hostname,
const char *service,
return (fcntl(fd, F_SETFL, flags) == 0);
}
-/* We only handle IPv4 and IPv6 */
-#define MAX_PROTOS 2
-
-static void remove_fd(struct pollfd pfd[],
- const struct addrinfo *addr[],
- socklen_t slen[],
- unsigned int *num,
- unsigned int i)
+static int start_connect(const struct addrinfo *addr, bool *immediate)
{
- memmove(pfd + i, pfd + i + 1, (*num - i - 1) * sizeof(pfd[0]));
- memmove(addr + i, addr + i + 1, (*num - i - 1) * sizeof(addr[0]));
- memmove(slen + i, slen + i + 1, (*num - i - 1) * sizeof(slen[0]));
- (*num)--;
+ int fd;
+
+ *immediate = false;
+
+ fd = socket(addr->ai_family, addr->ai_socktype, addr->ai_protocol);
+ if (fd == -1)
+ return fd;
+
+ if (!set_nonblock(fd, true))
+ goto close;
+
+ if (connect(fd, addr->ai_addr, addr->ai_addrlen) == 0) {
+ /* Immediate connect. */
+ *immediate = true;
+ return fd;
+ }
+
+ if (errno == EINPROGRESS)
+ return fd;
+
+close:
+ close_noerr(fd);
+ return -1;
}
-int net_connect(const struct addrinfo *addrinfo)
+
+int net_connect_async(const struct addrinfo *addrinfo, struct pollfd pfds[2])
{
- int sockfd = -1, saved_errno;
- unsigned int i, num;
- const struct addrinfo *ipv4 = NULL, *ipv6 = NULL;
- const struct addrinfo *addr[MAX_PROTOS];
- socklen_t slen[MAX_PROTOS];
- struct pollfd pfd[MAX_PROTOS];
+ const struct addrinfo *addr[2] = { NULL, NULL };
+ unsigned int i;
+ pfds[0].fd = pfds[1].fd = -1;
+ pfds[0].events = pfds[1].events = POLLOUT;
+
+ /* Give IPv6 a slight advantage, by trying it first. */
for (; addrinfo; addrinfo = addrinfo->ai_next) {
switch (addrinfo->ai_family) {
case AF_INET:
- if (!ipv4)
- ipv4 = addrinfo;
+ addr[1] = addrinfo;
break;
case AF_INET6:
- if (!ipv6)
- ipv6 = addrinfo;
+ addr[0] = addrinfo;
break;
+ default:
+ continue;
}
}
- num = 0;
- /* We give IPv6 a slight edge by connecting it first. */
- if (ipv6) {
- addr[num] = ipv6;
- slen[num] = sizeof(struct sockaddr_in6);
- pfd[num].fd = socket(AF_INET6, ipv6->ai_socktype,
- ipv6->ai_protocol);
- if (pfd[num].fd != -1)
- num++;
+ /* In case we found nothing. */
+ errno = ENOENT;
+ for (i = 0; i < 2; i++) {
+ bool immediate;
+
+ if (!addr[i])
+ continue;
+
+ pfds[i].fd = start_connect(addr[i], &immediate);
+ if (immediate) {
+ if (pfds[!i].fd != -1)
+ close(pfds[!i].fd);
+ if (!set_nonblock(pfds[i].fd, false)) {
+ close_noerr(pfds[i].fd);
+ return -1;
+ }
+ return pfds[0].fd;
+ }
}
- if (ipv4) {
- addr[num] = ipv4;
- slen[num] = sizeof(struct sockaddr_in);
- pfd[num].fd = socket(AF_INET, ipv4->ai_socktype,
- ipv4->ai_protocol);
- if (pfd[num].fd != -1)
- num++;
+
+ if (pfds[0].fd != -1 || pfds[1].fd != -1)
+ errno = EINPROGRESS;
+ return -1;
+}
+
+void net_connect_abort(struct pollfd pfds[2])
+{
+ unsigned int i;
+
+ for (i = 0; i < 2; i++) {
+ if (pfds[i].fd != -1)
+ close_noerr(pfds[i].fd);
+ pfds[i].fd = -1;
}
+}
+
+int net_connect_complete(struct pollfd pfds[2])
+{
+ unsigned int i;
+
+ assert(pfds[0].fd != -1 || pfds[1].fd != -1);
+
+ for (i = 0; i < 2; i++) {
+ int err;
+ socklen_t errlen = sizeof(err);
- for (i = 0; i < num; i++) {
- if (!set_nonblock(pfd[i].fd, true)) {
- remove_fd(pfd, addr, slen, &num, i--);
+ if (pfds[i].fd == -1)
continue;
+ if (getsockopt(pfds[i].fd, SOL_SOCKET, SO_ERROR, &err,
+ &errlen) != 0) {
+ net_connect_abort(pfds);
+ return -1;
}
- /* Connect *can* be instant. */
- if (connect(pfd[i].fd, addr[i]->ai_addr, slen[i]) == 0)
- goto got_one;
- if (errno != EINPROGRESS) {
- /* Remove dead one. */
- remove_fd(pfd, addr, slen, &num, i--);
+ if (err == 0) {
+ /* Don't hand them non-blocking fd! */
+ if (!set_nonblock(pfds[i].fd, false)) {
+ net_connect_abort(pfds);
+ return -1;
+ }
+ /* Close other one. */
+ if (pfds[!i].fd != -1)
+ close(pfds[!i].fd);
+ return pfds[i].fd;
}
- pfd[i].events = POLLOUT;
}
- while (num && poll(pfd, num, -1) != -1) {
- for (i = 0; i < num; i++) {
- int err;
- socklen_t errlen = sizeof(err);
- if (!pfd[i].revents)
- continue;
- if (getsockopt(pfd[i].fd, SOL_SOCKET, SO_ERROR, &err,
- &errlen) != 0)
- goto out;
- if (err == 0)
- goto got_one;
-
- /* Remove dead one. */
- errno = err;
- remove_fd(pfd, addr, slen, &num, i--);
- }
- }
+ /* Still going... */
+ errno = EINPROGRESS;
+ return -1;
+}
-got_one:
- /* We don't want to hand them a non-blocking socket! */
- if (set_nonblock(pfd[i].fd, false))
- sockfd = pfd[i].fd;
+int net_connect(const struct addrinfo *addrinfo)
+{
+ struct pollfd pfds[2];
+ int sockfd;
+
+ sockfd = net_connect_async(addrinfo, pfds);
+ /* Immediate connect or error is easy. */
+ if (sockfd >= 0 || errno != EINPROGRESS)
+ return sockfd;
+
+ while (poll(pfds, 2, -1) != -1) {
+ sockfd = net_connect_complete(pfds);
+ if (sockfd >= 0 || errno != EINPROGRESS)
+ return sockfd;
+ }
-out:
- saved_errno = errno;
- for (i = 0; i < num; i++)
- if (pfd[i].fd != sockfd)
- close(pfd[i].fd);
- errno = saved_errno;
- return sockfd;
+ net_connect_abort(pfds);
+ return -1;
}
struct addrinfo *net_server_lookup(const char *service,
/* Licensed under BSD-MIT - see LICENSE file for details */
#ifndef CCAN_NET_H
#define CCAN_NET_H
+#include <stdbool.h>
+
+struct pollfd;
+
/**
* net_client_lookup - look up a network name to connect to.
* @hostname: the name to look up
* #include <sys/socket.h>
* #include <stdio.h>
* #include <netdb.h>
+ * #include <poll.h>
* #include <err.h>
* ...
* struct addrinfo *addr;
*/
int net_connect(const struct addrinfo *addrinfo);
+/**
+ * net_connect_async - initiate connect to a server
+ * @addrinfo: linked list struct addrinfo (usually from net_client_lookup).
+ * @pfds: array of two struct pollfd.
+ *
+ * This begins connecting to a server described by @addrinfo,
+ * and places the one or two file descriptors into pfds[0] and pfds[1].
+ * It returns a valid file descriptor if connect() returned immediately.
+ *
+ * Otherwise it returns -1 and sets errno, most likely EINPROGRESS.
+ * In this case, poll() on pfds and call net_connect_complete().
+ *
+ * Example:
+ * struct pollfd pfds[2];
+ * ...
+ * fd = net_connect_async(addr, pfds);
+ * if (fd < 0 && errno != EINPROGRESS)
+ * err(1, "Failed to connect to ccan.ozlabs.org");
+ */
+int net_connect_async(const struct addrinfo *addrinfo, struct pollfd *pfds);
+
+/**
+ * net_connect_complete - complete net_connect_async call.
+ * @pfds: array of two struct pollfd handed to net_connect_async.
+ *
+ * When poll() reports some activity, this determines whether a connection
+ * has completed. If so, it cleans up and returns the connected fd.
+ * Otherwise, it returns -1, and sets errno (usually EINPROGRESS).
+ *
+ * Example:
+ * // After net_connect_async.
+ * while (fd < 0 && errno == EINPROGRESS) {
+ * // Wait for activity...
+ * poll(pfds, 2, -1);
+ * fd = net_connect_complete(pfds);
+ * }
+ * if (fd < 0)
+ * err(1, "connecting");
+ * printf("Connected on fd %i!\n", fd);
+ */
+int net_connect_complete(struct pollfd *pfds);
+
+/**
+ * net_connect_abort - abort a net_connect_async call.
+ * @pfds: array of two struct pollfd handed to net_connect_async.
+ *
+ * Closes the file descriptors.
+ *
+ * Example:
+ * // After net_connect_async.
+ * if (poll(pfds, 2, 1000) == 0) { // Timeout.
+ * net_connect_abort(pfds);
+ * fd = -1;
+ * } else {
+ * fd = net_connect_complete(pfds);
+ * if (fd < 0)
+ * err(1, "connecting");
+ * }
+ */
+void net_connect_abort(struct pollfd *pfds);
+
/**
* net_server_lookup - look up a service name to bind to.
* @service: the service to look up
projects / ccan / commitdiff