add osmo_sockaddr_str API
For handling RTP IP addresses and ports, osmo-mgw, osmo-bsc and osmo-msc
so far have their own separate shims and code duplication around
inet_ntoa(), htons(), sockaddr conversions etc. Unify and standardize
with this common API.
In the MGW endpoint FSM that was introduced in osmo-bsc and which I
would like to re-use for osmo-msc (upcoming patch moving that to
osmo-mgw), it has turned out that using char* IP address and uint16_t
port number types are a convenient common denominator for logging,
MGCP message composition and GSM48. Ongoing osmo-msc work also uses this
for MNCC.
This is of course potentially useful for any other IP+port combinations
besides RTP stream handling.
Needless to say that most current implementations will probably stay
with their current own conversion code for a long time; for current
osmo-{bsc,msc,mgw} work (MGW endpoint FSM) though, I would like to move
to this API here.
Change-Id: Id617265337f09dfb6ddfe111ef5e578cd3dc9f63
diff --git a/src/sockaddr_str.c b/src/sockaddr_str.c
new file mode 100644
index 0000000..c9d9a94
--- /dev/null
+++ b/src/sockaddr_str.c
@@ -0,0 +1,378 @@
+/*! \file sockaddr_str.c
+ * Common implementation to store an IP address and port.
+ */
+/*
+ * (C) 2019 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de>
+ *
+ * Author: neels@hofmeyr.de
+ *
+ * All Rights Reserved
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include "config.h"
+
+#ifdef HAVE_NETINET_IN_H
+#include <string.h>
+#include <errno.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+#include <osmocom/core/sockaddr_str.h>
+#include <osmocom/core/utils.h>
+#include <osmocom/core/byteswap.h>
+
+/*! \addtogroup sockaddr_str
+ *
+ * Common operations to store IP address as a char string along with a uint16_t port number.
+ *
+ * Convert IP address string to/from in_addr and in6_addr, with bounds checking and basic housekeeping.
+ *
+ * The initial purpose is to store and translate IP address info between GSM CC and MGCP protocols -- GSM mostly using
+ * 32-bit IPv4 addresses, and MGCP forwarding addresses as ASCII character strings.
+ *
+ * (At the time of writing, there are no immediate IPv6 users that come to mind, but it seemed appropriate to
+ * accommodate both address families from the start.)
+ *
+ * @{
+ * \file sockaddr_str.c
+ */
+
+/*! Return true if all elements of the osmo_sockaddr_str instance are set.
+ * \param[in] sockaddr_str The instance to examine.
+ * \return True iff ip is nonempty, port is not 0 and af is set to either AF_INET or AF_INET6.
+ */
+bool osmo_sockaddr_str_is_set(const struct osmo_sockaddr_str *sockaddr_str)
+{
+ return *sockaddr_str->ip
+ && sockaddr_str->port
+ && (sockaddr_str->af == AF_INET || sockaddr_str->af == AF_INET6);
+}
+
+/*! Distinguish between valid IPv4 and IPv6 strings.
+ * This does not verify whether the string is a valid IP address; it assumes that the input is a valid IP address, and
+ * on that premise returns whether it is an IPv4 or IPv6 string, by looking for '.' and ':' characters. It is safe to
+ * feed invalid address strings, but the return value is only guaranteed to be meaningful if the input was valid.
+ * \param[in] ip Valid IP address string.
+ * \return AF_INET or AF_INET6, or AF_UNSPEC if neither '.' nor ':' are found in the string.
+ */
+int osmo_ip_str_type(const char *ip)
+{
+ if (!ip)
+ return AF_UNSPEC;
+ /* Could also be IPv4-mapped IPv6 format with both colons and dots: x:x:x:x:x:x:d.d.d.d */
+ if (strchr(ip, ':'))
+ return AF_INET6;
+ if (strchr(ip, '.'))
+ return AF_INET;
+ return AF_UNSPEC;
+}
+
+/*! Safely copy the given ip string to sockaddr_str, classify to AF_INET or AF_INET6, and set the port.
+ * Data will be written to sockaddr_str even if an error is returned.
+ * \param[out] sockaddr_str The instance to copy to.
+ * \param[in] ip Valid IP address string.
+ * \param[in] port Port number.
+ * \return 0 on success, negative if copying the address string failed (e.g. too long), if the address family could
+ * not be detected (i.e. if osmo_ip_str_type() returned AF_UNSPEC), or if sockaddr_str is NULL.
+ */
+int osmo_sockaddr_str_from_str(struct osmo_sockaddr_str *sockaddr_str, const char *ip, uint16_t port)
+{
+ int rc;
+ if (!sockaddr_str)
+ return -ENOSPC;
+ if (!ip)
+ ip = "";
+ *sockaddr_str = (struct osmo_sockaddr_str){
+ .af = osmo_ip_str_type(ip),
+ .port = port,
+ };
+ rc = osmo_strlcpy(sockaddr_str->ip, ip, sizeof(sockaddr_str->ip));
+ if (rc <= 0)
+ return -EIO;
+ if (rc >= sizeof(sockaddr_str->ip))
+ return -ENOSPC;
+ if (sockaddr_str->af == AF_UNSPEC)
+ return -EINVAL;
+ return 0;
+}
+
+/*! Convert IPv4 address to osmo_sockaddr_str, and set port.
+ * \param[out] sockaddr_str The instance to copy to.
+ * \param[in] addr IPv4 address data.
+ * \param[in] port Port number.
+ * \return 0 on success, negative on error.
+ */
+int osmo_sockaddr_str_from_in_addr(struct osmo_sockaddr_str *sockaddr_str, const struct in_addr *addr, uint16_t port)
+{
+ if (!sockaddr_str)
+ return -ENOSPC;
+ *sockaddr_str = (struct osmo_sockaddr_str){
+ .af = AF_INET,
+ .port = port,
+ };
+ if (!inet_ntop(AF_INET, addr, sockaddr_str->ip, sizeof(sockaddr_str->ip)))
+ return -ENOSPC;
+ return 0;
+}
+
+/*! Convert IPv6 address to osmo_sockaddr_str, and set port.
+ * \param[out] sockaddr_str The instance to copy to.
+ * \param[in] addr IPv6 address data.
+ * \param[in] port Port number.
+ * \return 0 on success, negative on error.
+ */
+int osmo_sockaddr_str_from_in6_addr(struct osmo_sockaddr_str *sockaddr_str, const struct in6_addr *addr, uint16_t port)
+{
+ if (!sockaddr_str)
+ return -ENOSPC;
+ *sockaddr_str = (struct osmo_sockaddr_str){
+ .af = AF_INET6,
+ .port = port,
+ };
+ if (!inet_ntop(AF_INET6, addr, sockaddr_str->ip, sizeof(sockaddr_str->ip)))
+ return -ENOSPC;
+ return 0;
+}
+
+/*! Convert IPv4 address from 32bit host-byte-order to osmo_sockaddr_str, and set port.
+ * \param[out] sockaddr_str The instance to copy to.
+ * \param[in] addr 32bit IPv4 address data.
+ * \param[in] port Port number.
+ * \return 0 on success, negative on error.
+ */
+int osmo_sockaddr_str_from_32(struct osmo_sockaddr_str *sockaddr_str, uint32_t ip, uint16_t port)
+{
+ struct in_addr addr;
+ if (!sockaddr_str)
+ return -ENOSPC;
+ addr.s_addr = ip;
+ return osmo_sockaddr_str_from_in_addr(sockaddr_str, &addr, port);
+}
+
+/*! Convert IPv4 address from 32bit network-byte-order to osmo_sockaddr_str, and set port.
+ * \param[out] sockaddr_str The instance to copy to.
+ * \param[in] addr 32bit IPv4 address data.
+ * \param[in] port Port number.
+ * \return 0 on success, negative on error.
+ */
+int osmo_sockaddr_str_from_32n(struct osmo_sockaddr_str *sockaddr_str, uint32_t ip, uint16_t port)
+{
+ if (!sockaddr_str)
+ return -ENOSPC;
+ return osmo_sockaddr_str_from_32(sockaddr_str, osmo_ntohl(ip), port);
+}
+
+/*! Convert IPv4 address and port to osmo_sockaddr_str.
+ * \param[out] sockaddr_str The instance to copy to.
+ * \param[in] src IPv4 address and port data.
+ * \return 0 on success, negative on error.
+ */
+int osmo_sockaddr_str_from_sockaddr_in(struct osmo_sockaddr_str *sockaddr_str, const struct sockaddr_in *src)
+{
+ if (!sockaddr_str)
+ return -ENOSPC;
+ if (!src)
+ return -EINVAL;
+ if (src->sin_family != AF_INET)
+ return -EINVAL;
+ return osmo_sockaddr_str_from_in_addr(sockaddr_str, &src->sin_addr, osmo_ntohs(src->sin_port));
+}
+
+/*! Convert IPv6 address and port to osmo_sockaddr_str.
+ * \param[out] sockaddr_str The instance to copy to.
+ * \param[in] src IPv6 address and port data.
+ * \return 0 on success, negative on error.
+ */
+int osmo_sockaddr_str_from_sockaddr_in6(struct osmo_sockaddr_str *sockaddr_str, const struct sockaddr_in6 *src)
+{
+ if (!sockaddr_str)
+ return -ENOSPC;
+ if (!src)
+ return -EINVAL;
+ if (src->sin6_family != AF_INET6)
+ return -EINVAL;
+ return osmo_sockaddr_str_from_in6_addr(sockaddr_str, &src->sin6_addr, osmo_ntohs(src->sin6_port));
+}
+
+/*! Convert IPv4 or IPv6 address and port to osmo_sockaddr_str.
+ * \param[out] sockaddr_str The instance to copy to.
+ * \param[in] src IPv4 or IPv6 address and port data.
+ * \return 0 on success, negative if src does not indicate AF_INET nor AF_INET6 (or if the conversion fails, which
+ * should not be possible in practice).
+ */
+int osmo_sockaddr_str_from_sockaddr(struct osmo_sockaddr_str *sockaddr_str, const struct sockaddr_storage *src)
+{
+ const struct sockaddr_in *sin = (void*)src;
+ const struct sockaddr_in6 *sin6 = (void*)src;
+ if (!sockaddr_str)
+ return -ENOSPC;
+ if (!src)
+ return -EINVAL;
+ if (sin->sin_family == AF_INET)
+ return osmo_sockaddr_str_from_sockaddr_in(sockaddr_str, sin);
+ if (sin6->sin6_family == AF_INET6)
+ return osmo_sockaddr_str_from_sockaddr_in6(sockaddr_str, sin6);
+ return -EINVAL;
+}
+
+/*! Convert osmo_sockaddr_str address string to IPv4 address data.
+ * \param[in] sockaddr_str The instance to convert the IP of.
+ * \param[out] dst IPv4 address data to write to.
+ * \return 0 on success, negative on error (e.g. invalid IPv4 address string).
+ */
+int osmo_sockaddr_str_to_in_addr(const struct osmo_sockaddr_str *sockaddr_str, struct in_addr *dst)
+{
+ int rc;
+ if (!sockaddr_str)
+ return -EINVAL;
+ if (!dst)
+ return -ENOSPC;
+ if (sockaddr_str->af != AF_INET)
+ return -EAFNOSUPPORT;
+ rc = inet_pton(AF_INET, sockaddr_str->ip, dst);
+ if (rc != 1)
+ return -EINVAL;
+ return 0;
+}
+
+/*! Convert osmo_sockaddr_str address string to IPv6 address data.
+ * \param[in] sockaddr_str The instance to convert the IP of.
+ * \param[out] dst IPv6 address data to write to.
+ * \return 0 on success, negative on error (e.g. invalid IPv6 address string).
+ */
+int osmo_sockaddr_str_to_in6_addr(const struct osmo_sockaddr_str *sockaddr_str, struct in6_addr *dst)
+{
+ int rc;
+ if (!sockaddr_str)
+ return -EINVAL;
+ if (!dst)
+ return -ENOSPC;
+ if (sockaddr_str->af != AF_INET6)
+ return -EINVAL;
+ rc = inet_pton(AF_INET6, sockaddr_str->ip, dst);
+ if (rc != 1)
+ return -EINVAL;
+ return 0;
+}
+
+/*! Convert osmo_sockaddr_str address string to IPv4 address data in host-byte-order.
+ * \param[in] sockaddr_str The instance to convert the IP of.
+ * \param[out] dst IPv4 address data in 32bit host-byte-order format to write to.
+ * \return 0 on success, negative on error (e.g. invalid IPv4 address string).
+ */
+int osmo_sockaddr_str_to_32(const struct osmo_sockaddr_str *sockaddr_str, uint32_t *ip)
+{
+ int rc;
+ struct in_addr addr;
+ if (!sockaddr_str)
+ return -EINVAL;
+ if (!ip)
+ return -ENOSPC;
+ rc = osmo_sockaddr_str_to_in_addr(sockaddr_str, &addr);
+ if (rc)
+ return rc;
+ *ip = addr.s_addr;
+ return 0;
+}
+
+/*! Convert osmo_sockaddr_str address string to IPv4 address data in network-byte-order.
+ * \param[in] sockaddr_str The instance to convert the IP of.
+ * \param[out] dst IPv4 address data in 32bit network-byte-order format to write to.
+ * \return 0 on success, negative on error (e.g. invalid IPv4 address string).
+ */
+int osmo_sockaddr_str_to_32n(const struct osmo_sockaddr_str *sockaddr_str, uint32_t *ip)
+{
+ int rc;
+ uint32_t ip_h;
+ if (!sockaddr_str)
+ return -EINVAL;
+ if (!ip)
+ return -ENOSPC;
+ rc = osmo_sockaddr_str_to_32(sockaddr_str, &ip_h);
+ if (rc)
+ return rc;
+ *ip = osmo_htonl(ip_h);
+ return 0;
+}
+
+/*! Convert osmo_sockaddr_str address string and port to IPv4 address and port data.
+ * \param[in] sockaddr_str The instance to convert the IP and port of.
+ * \param[out] dst IPv4 address and port data to write to.
+ * \return 0 on success, negative on error (e.g. invalid IPv4 address string).
+ */
+int osmo_sockaddr_str_to_sockaddr_in(const struct osmo_sockaddr_str *sockaddr_str, struct sockaddr_in *dst)
+{
+ if (!sockaddr_str)
+ return -EINVAL;
+ if (!dst)
+ return -ENOSPC;
+ if (sockaddr_str->af != AF_INET)
+ return -EINVAL;
+ *dst = (struct sockaddr_in){
+ .sin_family = sockaddr_str->af,
+ .sin_port = osmo_htons(sockaddr_str->port),
+ };
+ return osmo_sockaddr_str_to_in_addr(sockaddr_str, &dst->sin_addr);
+}
+
+/*! Convert osmo_sockaddr_str address string and port to IPv6 address and port data.
+ * \param[in] sockaddr_str The instance to convert the IP and port of.
+ * \param[out] dst IPv6 address and port data to write to.
+ * \return 0 on success, negative on error (e.g. invalid IPv6 address string).
+ */
+int osmo_sockaddr_str_to_sockaddr_in6(const struct osmo_sockaddr_str *sockaddr_str, struct sockaddr_in6 *dst)
+{
+ if (!sockaddr_str)
+ return -EINVAL;
+ if (!dst)
+ return -ENOSPC;
+ if (sockaddr_str->af != AF_INET6)
+ return -EINVAL;
+ *dst = (struct sockaddr_in6){
+ .sin6_family = sockaddr_str->af,
+ .sin6_port = osmo_htons(sockaddr_str->port),
+ };
+ return osmo_sockaddr_str_to_in6_addr(sockaddr_str, &dst->sin6_addr);
+}
+
+/*! Convert osmo_sockaddr_str address string and port to IPv4 or IPv6 address and port data.
+ * Depending on sockaddr_str->af, dst will be handled as struct sockaddr_in or struct sockaddr_in6.
+ * \param[in] sockaddr_str The instance to convert the IP and port of.
+ * \param[out] dst IPv4/IPv6 address and port data to write to.
+ * \return 0 on success, negative on error (e.g. invalid IP address string for the family indicated by sockaddr_str->af).
+ */
+int osmo_sockaddr_str_to_sockaddr(const struct osmo_sockaddr_str *sockaddr_str, struct sockaddr_storage *dst)
+{
+ if (!sockaddr_str)
+ return -EINVAL;
+ if (!dst)
+ return -ENOSPC;
+ switch (sockaddr_str->af) {
+ case AF_INET:
+ return osmo_sockaddr_str_to_sockaddr_in(sockaddr_str, (void*)dst);
+ case AF_INET6:
+ return osmo_sockaddr_str_to_sockaddr_in6(sockaddr_str, (void*)dst);
+ default:
+ return -EINVAL;
+ }
+}
+
+/*! @} */
+#endif // HAVE_NETINET_IN_H