From 06e47cd5c6d93afa59eadfa6e2ee89b7415180e0 Mon Sep 17 00:00:00 2001
From: Andre Noll <maan@systemlinux.org>
Date: Fri, 6 Sep 2013 23:17:42 +0000
Subject: [PATCH] net: Split makesock(), part 1: Introduce lookup_address().
The lookup part is relatively independent and might be useful on its
own, so create lookup_address().
---
net.c | 107 ++++++++++++++++++++++++++++++++++------------------------
1 file changed, 63 insertions(+), 44 deletions(-)
diff --git a/net.c b/net.c
index 70d3ec0f..ccb9632d 100644
--- a/net.c
+++ b/net.c
@@ -343,72 +343,91 @@ static void flowopt_cleanup(struct flowopts *fo)
free(fo);
}
-/**
- * Resolve IPv4/IPv6 address and create a ready-to-use active or passive socket.
+/*
+ * Resolve an IPv4/IPv6 address.
*
* \param l4type The layer-4 type (\p IPPROTO_xxx).
- * \param passive Whether this is a passive (1) or active (0) socket.
+ * \param passive Whether \p AI_PASSIVE should be included as hint.
* \param host Remote or local hostname or IPv/6 address string.
- * \param port_number Decimal port number.
- * \param fo Socket options to be set before making the connection.
+ * \param port_number Used to set the port in each returned address structure.
+ * \param result addrinfo structures are returned here.
*
- * This creates a ready-made IPv4/v6 socket structure after looking up the
- * necessary parameters. The interpretation of \a host depends on the value of
- * \a passive:
- * - on a passive socket host is interpreted as an interface IPv4/6 address
- * (can be left NULL);
- * - on an active socket, \a host is the peer DNS name or IPv4/6 address
- * to connect to;
- * - \a port_number is in either case the numeric port number (not service
- * string).
+ * The interpretation of \a host depends on the value of \a passive. On a
+ * passive socket host is interpreted as an interface IPv4/6 address (can be
+ * left NULL). On an active socket, \a host is the peer DNS name or IPv4/6
+ * address to connect to.
*
- * Furthermore, bind(2) is called on passive sockets, and connect(2) on active
- * sockets. The algorithm tries all possible address combinations until it
- * succeeds. If \a fo is supplied, options are set and cleanup is performed.
+ * \return Standard.
*
- * \return This function returns 1 on success and \a -E_ADDRESS_LOOKUP when no
- * matching connection could be set up (with details in the error log).
- *
- * \sa ipv6(7), getaddrinfo(3), bind(2), connect(2).
+ * \sa getaddrinfo(3).
*/
-int makesock(unsigned l4type, bool passive,
- const char *host, uint16_t port_number,
- struct flowopts *fo)
+static int lookup_address(unsigned l4type, bool passive, const char *host,
+ int port_number, struct addrinfo **result)
{
- struct addrinfo *local = NULL, *src = NULL, *remote = NULL,
- *dst = NULL, hints;
- int rc, on = 1, sockfd = -1,
- socktype = sock_type(l4type);
+ int ret;
char port[6]; /* port number has at most 5 digits */
+ struct addrinfo *addr = NULL, hints;
- sprintf(port, "%u", port_number);
+ *result = NULL;
+ sprintf(port, "%u", port_number & 0xffff);
/* Set up address hint structure */
memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_UNSPEC;
- hints.ai_socktype = socktype;
- /*
+ hints.ai_socktype = sock_type(l4type);
+ /*
* getaddrinfo does not support SOCK_DCCP, so for the sake of lookup
* (and only then) pretend to be UDP.
*/
if (l4type == IPPROTO_DCCP)
hints.ai_socktype = SOCK_DGRAM;
-
/* only use addresses available on the host */
hints.ai_flags = AI_ADDRCONFIG;
-
if (passive && host == NULL)
hints.ai_flags |= AI_PASSIVE;
-
/* Obtain local/remote address information */
- if ((rc = getaddrinfo(host, port, &hints, passive ? &local : &remote))) {
- PARA_ERROR_LOG("can not resolve %s address %s#%s: %s.\n",
- layer4_name(l4type),
- host? host : (passive? "[loopback]" : "[localhost]"),
- port, gai_strerror(rc));
- rc = -E_ADDRESS_LOOKUP;
- goto out;
+ ret = getaddrinfo(host, port, &hints, &addr);
+ if (ret != 0) {
+ PARA_ERROR_LOG("can not resolve %s address %s#%s: %s\n",
+ layer4_name(l4type),
+ host? host : (passive? "[loopback]" : "[localhost]"),
+ port, gai_strerror(ret));
+ return -E_ADDRESS_LOOKUP;
}
+ *result = addr;
+ return 1;
+}
+/**
+ * Resolve IPv4/IPv6 address and create a ready-to-use active or passive socket.
+ *
+ * \param l4type The layer-4 type (\p IPPROTO_xxx).
+ * \param passive Whether this is a passive or active socket.
+ * \param host Passed to \ref \a lookup_address().
+ * \param port_number Passed to \ref \a lookup_address().
+ * \param fo Socket options to be set before making the connection.
+ *
+ * This creates a ready-made IPv4/v6 socket structure after looking up the
+ * necessary parameters.
+ *
+ * bind(2) is called on passive sockets, and connect(2) on active sockets. The
+ * algorithm tries all possible address combinations until it succeeds. If \a
+ * fo is supplied, options are set and cleanup is performed.
+ *
+ * \return Standard.
+ *
+ * \sa \ref lookup_address(), ipv6(7), getaddrinfo(3), bind(2), connect(2).
+ */
+int makesock(unsigned l4type, bool passive,
+ const char *host, uint16_t port_number,
+ struct flowopts *fo)
+{
+ struct addrinfo *local = NULL, *src = NULL, *remote = NULL, *dst = NULL;
+ int rc, on = 1, sockfd = -1;
+
+ rc = lookup_address(l4type, passive, host, port_number, passive?
+ &local : &remote);
+ if (rc < 0)
+ goto out;
/* Iterate over all src/dst combination, exhausting dst first */
for (src = local, dst = remote; src != NULL || dst != NULL; /* no op */ ) {
if (src && dst && src->ai_family == AF_INET
@@ -416,7 +435,7 @@ int makesock(unsigned l4type, bool passive,
goto get_next_dst; /* v4 -> v6 is not possible */
sockfd = socket(src ? src->ai_family : dst->ai_family,
- socktype, l4type);
+ sock_type(l4type), l4type);
if (sockfd < 0)
goto get_next_dst;
@@ -465,9 +484,9 @@ out:
if (src == NULL && dst == NULL) {
if (rc >= 0)
rc = -E_MAKESOCK;
- PARA_ERROR_LOG("can not create %s socket %s#%s.\n",
+ PARA_ERROR_LOG("can not create %s socket %s#%d.\n",
layer4_name(l4type), host? host : (passive?
- "[loopback]" : "[localhost]"), port);
+ "[loopback]" : "[localhost]"), port_number);
return rc;
}
return sockfd;
--
2.39.5