From: Martin Belanger <martin.belanger@dell.com>
Date: Fri, 18 Aug 2023 01:28:57 +0000 (-0400)
Subject: util: Add functions to parse the system's interfaces
X-Git-Tag: v1.6~43
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=ead417d45b3e7409e217224227f5c2015a272a63;p=users%2Fsagi%2Flibnvme.git

util: Add functions to parse the system's interfaces

1) nvme_iface_matching_addr() identifies which interface owns a
specific IP address.

2) nvme_iface_primary_addr_matches() checks that the primary IP
address of a given interface matches a specific IP address.

Signed-off-by: Martin Belanger <martin.belanger@dell.com>
---

diff --git a/src/nvme/util.c b/src/nvme/util.c
index 77584538..8fe094d5 100644
--- a/src/nvme/util.c
+++ b/src/nvme/util.c
@@ -982,3 +982,79 @@ bool nvme_ipaddrs_eq(const char *addr1, const char *addr2)
 	return false;
 }
 #endif /* HAVE_NETDB */
+
+#ifdef HAVE_NETDB
+const char *nvme_iface_matching_addr(const struct ifaddrs *iface_list, const char *addr)
+{
+	const struct ifaddrs *iface_it;
+	struct addrinfo *info = NULL, hint = { .ai_flags = AI_NUMERICHOST, .ai_family = AF_UNSPEC };
+	const char *iface_name = NULL;
+
+	if (!iface_list || !addr || getaddrinfo(addr, 0, &hint, &info) || !info)
+		return NULL;
+
+	/* Walk through the linked list */
+	for (iface_it = iface_list; iface_it != NULL; iface_it = iface_it->ifa_next) {
+		struct sockaddr *ifaddr = iface_it->ifa_addr;
+
+		if (ifaddr && (ifaddr->sa_family == AF_INET || ifaddr->sa_family == AF_INET6) &&
+		    _nvme_ipaddrs_eq(info->ai_addr, ifaddr)) {
+			iface_name = iface_it->ifa_name;
+			break;
+		}
+	}
+
+	freeaddrinfo(info);
+
+	return iface_name;
+}
+
+bool nvme_iface_primary_addr_matches(const struct ifaddrs *iface_list, const char *iface, const char *addr)
+{
+	const struct ifaddrs *iface_it;
+	struct addrinfo *info = NULL, hint = { .ai_flags = AI_NUMERICHOST, .ai_family = AF_UNSPEC };
+	bool match_found = false;
+
+	if (!iface_list || !addr || getaddrinfo(addr, 0, &hint, &info) || !info)
+		return false;
+
+	/* Walk through the linked list */
+	for (iface_it = iface_list; iface_it != NULL; iface_it = iface_it->ifa_next) {
+		if (strcmp(iface, iface_it->ifa_name))
+			continue; /* Not the interface we're looking for*/
+
+		/* The interface list is ordered in a way that the primary
+		 * address is listed first. As soon as the parsed address
+		 * matches the family of the address we're looking for, we
+		 * have found the primary address for that family.
+		 */
+		if (iface_it->ifa_addr && (iface_it->ifa_addr->sa_family == info->ai_addr->sa_family)) {
+			match_found = _nvme_ipaddrs_eq(info->ai_addr, iface_it->ifa_addr);
+			break;
+		}
+	}
+
+	freeaddrinfo(info);
+
+	return match_found;
+}
+
+#else /* HAVE_NETDB */
+
+const char *nvme_iface_matching_addr(const struct ifaddrs *iface_list, const char *addr)
+{
+	nvme_msg(NULL, LOG_ERR, "no support for interface lookup; "
+		"recompile with libnss support.\n");
+
+	return NULL;
+}
+
+bool nvme_iface_primary_addr_matches(const struct ifaddrs *iface_list, const char *iface, const char *addr)
+{
+	nvme_msg(NULL, LOG_ERR, "no support for interface lookup; "
+		"recompile with libnss support.\n");
+
+	return false;
+}
+
+#endif /* HAVE_NETDB */
diff --git a/src/nvme/util.h b/src/nvme/util.h
index 9d6faf36..0739cf2f 100644
--- a/src/nvme/util.h
+++ b/src/nvme/util.h
@@ -9,6 +9,8 @@
 #ifndef _LIBNVME_UTIL_H
 #define _LIBNVME_UTIL_H
 
+#include <ifaddrs.h>
+
 #include "types.h"
 
 /**
@@ -639,4 +641,31 @@ int nvme_uuid_random(unsigned char uuid[NVME_UUID_LEN]);
  */
 bool nvme_ipaddrs_eq(const char *addr1, const char *addr2);
 
+/**
+ * nvme_iface_matching_addr - Get interface matching @addr
+ * @iface_list: Interface list returned by getifaddrs()
+ * @addr: Address to match
+ *
+ * Parse the interface list pointed to by @iface_list looking
+ * for the interface that has @addr as one of its assigned
+ * addresses.
+ *
+ * Return: The name of the interface that owns @addr or NULL.
+ */
+const char *nvme_iface_matching_addr(const struct ifaddrs *iface_list, const char *addr);
+
+/**
+ * nvme_iface_primary_addr_matches - Check that interface's primary address matches
+ * @iface_list: Interface list returned by getifaddrs()
+ * @iface: Interface to match
+ * @addr: Address to match
+ *
+ * Parse the interface list pointed to by @iface_list and looking for
+ * interface @iface. The get its primary address and check if it matches
+ * @addr.
+ *
+ * Return: true if a match is found, false otherwise.
+ */
+bool nvme_iface_primary_addr_matches(const struct ifaddrs *iface_list, const char *iface, const char *addr);
+
 #endif /* _LIBNVME_UTIL_H */