1 files changed, 240 insertions, 0 deletions
diff --git a/lib/isc/unix/ifiter_getifaddrs.c b/lib/isc/unix/ifiter_getifaddrs.c
new file mode 100644
index 0000000..9f8b31a
--- /dev/null
+++ b/lib/isc/unix/ifiter_getifaddrs.c
@@ -0,0 +1,240 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0.  If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*! \file
+ * \brief
+ * Obtain the list of network interfaces using the getifaddrs(3) library.
+ */
+
+#include <ifaddrs.h>
+#include <stdbool.h>
+
+#include <isc/strerr.h>
+
+/*% Iterator Magic */
+#define IFITER_MAGIC ISC_MAGIC('I', 'F', 'I', 'G')
+/*% Valid Iterator */
+#define VALID_IFITER(t) ISC_MAGIC_VALID(t, IFITER_MAGIC)
+
+#ifdef __linux
+static bool seenv6 = false;
+#endif /* ifdef __linux */
+
+/*% Iterator structure */
+struct isc_interfaceiter {
+	unsigned int magic; /*%< Magic number. */
+	isc_mem_t *mctx;
+	void *buf;		 /*%< (unused) */
+	unsigned int bufsize;	 /*%< (always 0) */
+	struct ifaddrs *ifaddrs; /*%< List of ifaddrs */
+	struct ifaddrs *pos;	 /*%< Ptr to current ifaddr */
+	isc_interface_t current; /*%< Current interface data. */
+	isc_result_t result;	 /*%< Last result code. */
+#ifdef __linux
+	FILE *proc;
+	char entry[ISC_IF_INET6_SZ];
+	isc_result_t valid;
+#endif /* ifdef __linux */
+};
+
+isc_result_t
+isc_interfaceiter_create(isc_mem_t *mctx, isc_interfaceiter_t **iterp) {
+	isc_interfaceiter_t *iter;
+	isc_result_t result;
+	char strbuf[ISC_STRERRORSIZE];
+
+	REQUIRE(mctx != NULL);
+	REQUIRE(iterp != NULL);
+	REQUIRE(*iterp == NULL);
+
+	iter = isc_mem_get(mctx, sizeof(*iter));
+
+	iter->mctx = mctx;
+	iter->buf = NULL;
+	iter->bufsize = 0;
+	iter->ifaddrs = NULL;
+#ifdef __linux
+	/*
+	 * Only open "/proc/net/if_inet6" if we have never seen a IPv6
+	 * address returned by getifaddrs().
+	 */
+	if (!seenv6) {
+		iter->proc = fopen("/proc/net/if_inet6", "r");
+	} else {
+		iter->proc = NULL;
+	}
+	iter->valid = ISC_R_FAILURE;
+#endif /* ifdef __linux */
+
+	if (getifaddrs(&iter->ifaddrs) < 0) {
+		strerror_r(errno, strbuf, sizeof(strbuf));
+		UNEXPECTED_ERROR(__FILE__, __LINE__,
+				 "getting interface addresses: getifaddrs: %s",
+				 strbuf);
+		result = ISC_R_UNEXPECTED;
+		goto failure;
+	}
+
+	/*
+	 * A newly created iterator has an undefined position
+	 * until isc_interfaceiter_first() is called.
+	 */
+	iter->pos = NULL;
+	iter->result = ISC_R_FAILURE;
+
+	iter->magic = IFITER_MAGIC;
+	*iterp = iter;
+	return (ISC_R_SUCCESS);
+
+failure:
+#ifdef __linux
+	if (iter->proc != NULL) {
+		fclose(iter->proc);
+	}
+#endif				     /* ifdef __linux */
+	if (iter->ifaddrs != NULL) { /* just in case */
+		freeifaddrs(iter->ifaddrs);
+	}
+	isc_mem_put(mctx, iter, sizeof(*iter));
+	return (result);
+}
+
+/*
+ * Get information about the current interface to iter->current.
+ * If successful, return ISC_R_SUCCESS.
+ * If the interface has an unsupported address family,
+ * return ISC_R_IGNORE.
+ */
+
+static isc_result_t
+internal_current(isc_interfaceiter_t *iter) {
+	struct ifaddrs *ifa;
+	int family;
+	unsigned int namelen;
+
+	REQUIRE(VALID_IFITER(iter));
+
+	ifa = iter->pos;
+
+#ifdef __linux
+	if (iter->pos == NULL) {
+		return (linux_if_inet6_current(iter));
+	}
+#endif /* ifdef __linux */
+
+	INSIST(ifa != NULL);
+	INSIST(ifa->ifa_name != NULL);
+
+	if (ifa->ifa_addr == NULL) {
+		return (ISC_R_IGNORE);
+	}
+
+	family = ifa->ifa_addr->sa_family;
+	if (family != AF_INET && family != AF_INET6) {
+		return (ISC_R_IGNORE);
+	}
+
+#ifdef __linux
+	if (family == AF_INET6) {
+		seenv6 = true;
+	}
+#endif /* ifdef __linux */
+
+	memset(&iter->current, 0, sizeof(iter->current));
+
+	namelen = strlen(ifa->ifa_name);
+	if (namelen > sizeof(iter->current.name) - 1) {
+		namelen = sizeof(iter->current.name) - 1;
+	}
+
+	memset(iter->current.name, 0, sizeof(iter->current.name));
+	memmove(iter->current.name, ifa->ifa_name, namelen);
+
+	iter->current.flags = 0;
+
+	if ((ifa->ifa_flags & IFF_UP) != 0) {
+		iter->current.flags |= INTERFACE_F_UP;
+	}
+
+	if ((ifa->ifa_flags & IFF_POINTOPOINT) != 0) {
+		iter->current.flags |= INTERFACE_F_POINTTOPOINT;
+	}
+
+	if ((ifa->ifa_flags & IFF_LOOPBACK) != 0) {
+		iter->current.flags |= INTERFACE_F_LOOPBACK;
+	}
+
+	iter->current.af = family;
+
+	get_addr(family, &iter->current.address, ifa->ifa_addr, ifa->ifa_name);
+
+	if (ifa->ifa_netmask != NULL) {
+		get_addr(family, &iter->current.netmask, ifa->ifa_netmask,
+			 ifa->ifa_name);
+	}
+
+	if (ifa->ifa_dstaddr != NULL &&
+	    (iter->current.flags & INTERFACE_F_POINTTOPOINT) != 0)
+	{
+		get_addr(family, &iter->current.dstaddress, ifa->ifa_dstaddr,
+			 ifa->ifa_name);
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+/*
+ * Step the iterator to the next interface.  Unlike
+ * isc_interfaceiter_next(), this may leave the iterator
+ * positioned on an interface that will ultimately
+ * be ignored.  Return ISC_R_NOMORE if there are no more
+ * interfaces, otherwise ISC_R_SUCCESS.
+ */
+static isc_result_t
+internal_next(isc_interfaceiter_t *iter) {
+	if (iter->pos != NULL) {
+		iter->pos = iter->pos->ifa_next;
+	}
+	if (iter->pos == NULL) {
+#ifdef __linux
+		if (!seenv6) {
+			return (linux_if_inet6_next(iter));
+		}
+#endif /* ifdef __linux */
+		return (ISC_R_NOMORE);
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+static void
+internal_destroy(isc_interfaceiter_t *iter) {
+#ifdef __linux
+	if (iter->proc != NULL) {
+		fclose(iter->proc);
+	}
+	iter->proc = NULL;
+#endif /* ifdef __linux */
+	if (iter->ifaddrs) {
+		freeifaddrs(iter->ifaddrs);
+	}
+	iter->ifaddrs = NULL;
+}
+
+static void
+internal_first(isc_interfaceiter_t *iter) {
+#ifdef __linux
+	linux_if_inet6_first(iter);
+#endif /* ifdef __linux */
+	iter->pos = iter->ifaddrs;
+}