1 files changed, 291 insertions, 0 deletions
diff --git a/src/common/ip.c b/src/common/ip.c
new file mode 100644
index 0000000..cd73d49
--- /dev/null
+++ b/src/common/ip.c
@@ -0,0 +1,291 @@
+/*-------------------------------------------------------------------------
+ *
+ * ip.c
+ *	  IPv6-aware network access.
+ *
+ * Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/common/ip.c
+ *
+ * This file and the IPV6 implementation were initially provided by
+ * Nigel Kukard <nkukard@lbsd.net>, Linux Based Systems Design
+ * http://www.lbsd.net.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/socket.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#ifdef HAVE_NETINET_TCP_H
+#include <netinet/tcp.h>
+#endif
+#include <arpa/inet.h>
+#include <sys/file.h>
+
+#include "common/ip.h"
+
+
+
+#ifdef	HAVE_UNIX_SOCKETS
+static int	getaddrinfo_unix(const char *path,
+							 const struct addrinfo *hintsp,
+							 struct addrinfo **result);
+
+static int	getnameinfo_unix(const struct sockaddr_un *sa, int salen,
+							 char *node, int nodelen,
+							 char *service, int servicelen,
+							 int flags);
+#endif
+
+
+/*
+ *	pg_getaddrinfo_all - get address info for Unix, IPv4 and IPv6 sockets
+ */
+int
+pg_getaddrinfo_all(const char *hostname, const char *servname,
+				   const struct addrinfo *hintp, struct addrinfo **result)
+{
+	int			rc;
+
+	/* not all versions of getaddrinfo() zero *result on failure */
+	*result = NULL;
+
+#ifdef HAVE_UNIX_SOCKETS
+	if (hintp->ai_family == AF_UNIX)
+		return getaddrinfo_unix(servname, hintp, result);
+#endif
+
+	/* NULL has special meaning to getaddrinfo(). */
+	rc = getaddrinfo((!hostname || hostname[0] == '\0') ? NULL : hostname,
+					 servname, hintp, result);
+
+	return rc;
+}
+
+
+/*
+ *	pg_freeaddrinfo_all - free addrinfo structures for IPv4, IPv6, or Unix
+ *
+ * Note: the ai_family field of the original hint structure must be passed
+ * so that we can tell whether the addrinfo struct was built by the system's
+ * getaddrinfo() routine or our own getaddrinfo_unix() routine.  Some versions
+ * of getaddrinfo() might be willing to return AF_UNIX addresses, so it's
+ * not safe to look at ai_family in the addrinfo itself.
+ */
+void
+pg_freeaddrinfo_all(int hint_ai_family, struct addrinfo *ai)
+{
+#ifdef HAVE_UNIX_SOCKETS
+	if (hint_ai_family == AF_UNIX)
+	{
+		/* struct was built by getaddrinfo_unix (see pg_getaddrinfo_all) */
+		while (ai != NULL)
+		{
+			struct addrinfo *p = ai;
+
+			ai = ai->ai_next;
+			free(p->ai_addr);
+			free(p);
+		}
+	}
+	else
+#endif							/* HAVE_UNIX_SOCKETS */
+	{
+		/* struct was built by getaddrinfo() */
+		if (ai != NULL)
+			freeaddrinfo(ai);
+	}
+}
+
+
+/*
+ *	pg_getnameinfo_all - get name info for Unix, IPv4 and IPv6 sockets
+ *
+ * The API of this routine differs from the standard getnameinfo() definition
+ * in two ways: first, the addr parameter is declared as sockaddr_storage
+ * rather than struct sockaddr, and second, the node and service fields are
+ * guaranteed to be filled with something even on failure return.
+ */
+int
+pg_getnameinfo_all(const struct sockaddr_storage *addr, int salen,
+				   char *node, int nodelen,
+				   char *service, int servicelen,
+				   int flags)
+{
+	int			rc;
+
+#ifdef HAVE_UNIX_SOCKETS
+	if (addr && addr->ss_family == AF_UNIX)
+		rc = getnameinfo_unix((const struct sockaddr_un *) addr, salen,
+							  node, nodelen,
+							  service, servicelen,
+							  flags);
+	else
+#endif
+		rc = getnameinfo((const struct sockaddr *) addr, salen,
+						 node, nodelen,
+						 service, servicelen,
+						 flags);
+
+	if (rc != 0)
+	{
+		if (node)
+			strlcpy(node, "???", nodelen);
+		if (service)
+			strlcpy(service, "???", servicelen);
+	}
+
+	return rc;
+}
+
+
+#if defined(HAVE_UNIX_SOCKETS)
+
+/* -------
+ *	getaddrinfo_unix - get unix socket info using IPv6-compatible API
+ *
+ *	Bugs: only one addrinfo is set even though hintsp is NULL or
+ *		  ai_socktype is 0
+ *		  AI_CANONNAME is not supported.
+ * -------
+ */
+static int
+getaddrinfo_unix(const char *path, const struct addrinfo *hintsp,
+				 struct addrinfo **result)
+{
+	struct addrinfo hints;
+	struct addrinfo *aip;
+	struct sockaddr_un *unp;
+
+	*result = NULL;
+
+	MemSet(&hints, 0, sizeof(hints));
+
+	if (strlen(path) >= sizeof(unp->sun_path))
+		return EAI_FAIL;
+
+	if (hintsp == NULL)
+	{
+		hints.ai_family = AF_UNIX;
+		hints.ai_socktype = SOCK_STREAM;
+	}
+	else
+		memcpy(&hints, hintsp, sizeof(hints));
+
+	if (hints.ai_socktype == 0)
+		hints.ai_socktype = SOCK_STREAM;
+
+	if (hints.ai_family != AF_UNIX)
+	{
+		/* shouldn't have been called */
+		return EAI_FAIL;
+	}
+
+	aip = calloc(1, sizeof(struct addrinfo));
+	if (aip == NULL)
+		return EAI_MEMORY;
+
+	unp = calloc(1, sizeof(struct sockaddr_un));
+	if (unp == NULL)
+	{
+		free(aip);
+		return EAI_MEMORY;
+	}
+
+	aip->ai_family = AF_UNIX;
+	aip->ai_socktype = hints.ai_socktype;
+	aip->ai_protocol = hints.ai_protocol;
+	aip->ai_next = NULL;
+	aip->ai_canonname = NULL;
+	*result = aip;
+
+	unp->sun_family = AF_UNIX;
+	aip->ai_addr = (struct sockaddr *) unp;
+	aip->ai_addrlen = sizeof(struct sockaddr_un);
+
+	strcpy(unp->sun_path, path);
+
+	/*
+	 * If the supplied path starts with @, replace that with a zero byte for
+	 * the internal representation.  In that mode, the entire sun_path is the
+	 * address, including trailing zero bytes.  But we set the address length
+	 * to only include the length of the original string.  That way the
+	 * trailing zero bytes won't show up in any network or socket lists of the
+	 * operating system.  This is just a convention, also followed by other
+	 * packages.
+	 */
+	if (path[0] == '@')
+	{
+		unp->sun_path[0] = '\0';
+		aip->ai_addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(path);
+	}
+
+	/*
+	 * The standard recommendation for filling sun_len is to set it to the
+	 * struct size (independently of the actual path length).  However, that
+	 * draws an integer-overflow warning on AIX 7.1, where sun_len is just
+	 * uint8 yet the struct size exceeds 255 bytes.  It's likely that nothing
+	 * is paying attention to sun_len on that platform, but we have to do
+	 * something with it.  To suppress the warning, clamp the struct size to
+	 * what will fit in sun_len.
+	 */
+#ifdef HAVE_STRUCT_SOCKADDR_STORAGE_SS_LEN
+	unp->sun_len = Min(sizeof(struct sockaddr_un),
+					   ((size_t) 1 << (sizeof(unp->sun_len) * BITS_PER_BYTE)) - 1);
+#endif
+
+	return 0;
+}
+
+/*
+ * Convert an address to a hostname.
+ */
+static int
+getnameinfo_unix(const struct sockaddr_un *sa, int salen,
+				 char *node, int nodelen,
+				 char *service, int servicelen,
+				 int flags)
+{
+	int			ret;
+
+	/* Invalid arguments. */
+	if (sa == NULL || sa->sun_family != AF_UNIX ||
+		(node == NULL && service == NULL))
+		return EAI_FAIL;
+
+	if (node)
+	{
+		ret = snprintf(node, nodelen, "%s", "[local]");
+		if (ret < 0 || ret >= nodelen)
+			return EAI_MEMORY;
+	}
+
+	if (service)
+	{
+		/*
+		 * Check whether it looks like an abstract socket, but it could also
+		 * just be an empty string.
+		 */
+		if (sa->sun_path[0] == '\0' && sa->sun_path[1] != '\0')
+			ret = snprintf(service, servicelen, "@%s", sa->sun_path + 1);
+		else
+			ret = snprintf(service, servicelen, "%s", sa->sun_path);
+		if (ret < 0 || ret >= servicelen)
+			return EAI_MEMORY;
+	}
+
+	return 0;
+}
+#endif							/* HAVE_UNIX_SOCKETS */