Adding upstream version 3.4.23.upstream/3.4.23upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 192 insertions, 0 deletions

diff --git a/src/global/resolve_local.c b/src/global/resolve_local.c
new file mode 100644
index 0000000..c6ef848
--- /dev/null
+++ b/src/global/resolve_local.c
@@ -0,0 +1,192 @@
+/*++
+/* NAME
+/*	resolve_local 3
+/* SUMMARY
+/*	determine if domain resolves to local mail system
+/* SYNOPSIS
+/*	#include <resolve_local.h>
+/*
+/*	void	resolve_local_init()
+/*
+/*	int	resolve_local(domain)
+/*	const char *domain;
+/* DESCRIPTION
+/*	resolve_local() determines if the named domain resolves to the
+/*	local mail system, either by case-insensitive exact match
+/*	against the domains, files or tables listed in $mydestination,
+/*	or by a match of an [address-literal] against of the network
+/*	addresses listed in $inet_interfaces or in $proxy_interfaces.
+/*	The result is > 0 if the domain matches the list of local
+/*	domains and IP addresses, 0 when it does not match, and < 0
+/*	in case of error.
+/*
+/*	resolve_local_init() performs initialization. If this routine is
+/*	not called explicitly ahead of time, it will be called on the fly.
+/* BUGS
+/*	Calling resolve_local_init() on the fly is an incomplete solution.
+/*	It is bound to fail with applications that enter a chroot jail.
+/* SEE ALSO
+/*	own_inet_addr(3), find out my own network interfaces
+/*	match_list(3), generic pattern matching engine
+/*	match_ops(3), generic pattern matching operators
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/*	Wietse Venema
+/*	IBM T.J. Watson Research
+/*	P.O. Box 704
+/*	Yorktown Heights, NY 10598, USA
+/*--*/
+
+/* System library. */
+
+#include <sys_defs.h>
+
+/* Utility library. */
+
+#include <msg.h>
+#include <mymalloc.h>
+#include <string_list.h>
+#include <myaddrinfo.h>
+#include <valid_mailhost_addr.h>
+
+/* Global library. */
+
+#include <mail_params.h>
+#include <own_inet_addr.h>
+#include <resolve_local.h>
+
+/* Application-specific */
+
+static STRING_LIST *resolve_local_list;
+
+/* resolve_local_init - initialize lookup table */
+
+void    resolve_local_init(void)
+{
+    /* Allow on-the-fly update to make testing easier. */
+    if (resolve_local_list)
+	string_list_free(resolve_local_list);
+    resolve_local_list = string_list_init(VAR_MYDEST, MATCH_FLAG_RETURN,
+					  var_mydest);
+}
+
+/* resolve_local - match domain against list of local destinations */
+
+int     resolve_local(const char *addr)
+{
+    char   *saved_addr = mystrdup(addr);
+    char   *dest;
+    const char *bare_dest;
+    struct addrinfo *res0 = 0;
+    ssize_t len;
+
+    /*
+     * The optimizer will eliminate tests that always fail.
+     */
+#define RETURN(x) \
+    do { \
+	myfree(saved_addr); \
+	if (res0) \
+	    freeaddrinfo(res0); \
+	return(x); \
+    } while (0)
+
+    if (resolve_local_list == 0)
+	resolve_local_init();
+
+    /*
+     * Strip one trailing dot but not dot-dot.
+     * 
+     * XXX This should not be distributed all over the code. Problem is,
+     * addresses can enter the system via multiple paths: networks, local
+     * forward/alias/include files, even as the result of address rewriting.
+     */
+    len = strlen(saved_addr);
+    if (len == 0)
+	RETURN(0);
+    if (saved_addr[len - 1] == '.')
+	saved_addr[--len] = 0;
+    if (len == 0 || saved_addr[len - 1] == '.')
+	RETURN(0);
+
+    /*
+     * Compare the destination against the list of destinations that we
+     * consider local.
+     */
+    if (string_list_match(resolve_local_list, saved_addr))
+	RETURN(1);
+    if (resolve_local_list->error != 0)
+	RETURN(resolve_local_list->error);
+
+    /*
+     * Compare the destination against the list of interface addresses that
+     * we are supposed to listen on.
+     * 
+     * The destination may be an IPv6 address literal that was buried somewhere
+     * inside a deeply recursively nested address. This information comes
+     * from an untrusted source, and Wietse is not confident that everyone's
+     * getaddrinfo() etc. implementation is sufficiently robust. The syntax
+     * is complex enough with null field compression and with IPv4-in-IPv6
+     * addresses that errors are likely.
+     * 
+     * The solution below is ad-hoc. We neutralize the string as soon as we
+     * realize that its contents could be harmful. We neutralize the string
+     * here, instead of neutralizing it in every resolve_local() caller.
+     * That's because resolve_local knows how the address is going to be
+     * parsed and converted into binary form.
+     * 
+     * There are several more structural solutions to this.
+     * 
+     * - One solution is to disallow address literals. This is not as bad as it
+     * seems: I have never seen actual legitimate use of address literals.
+     * 
+     * - Another solution is to label each string with a trustworthiness label
+     * and to expect that all Postfix infrastructure will exercise additional
+     * caution when given a string with untrusted content. This is not likely
+     * to happen.
+     * 
+     * FIX 200501 IPv6 patch did not require "IPv6:" prefix in numerical
+     * addresses.
+     */
+    dest = saved_addr;
+    if (*dest == '[' && dest[len - 1] == ']') {
+	dest++;
+	dest[len -= 2] = 0;
+	if ((bare_dest = valid_mailhost_addr(dest, DO_GRIPE)) != 0
+	    && hostaddr_to_sockaddr(bare_dest, (char *) 0, 0, &res0) == 0) {
+	    if (own_inet_addr(res0->ai_addr) || proxy_inet_addr(res0->ai_addr))
+		RETURN(1);
+	}
+    }
+
+    /*
+     * Must be remote, or a syntax error.
+     */
+    RETURN(0);
+}
+
+#ifdef TEST
+
+#include <vstream.h>
+#include <mail_conf.h>
+
+int     main(int argc, char **argv)
+{
+    int     rc;
+
+    if (argc != 3)
+	msg_fatal("usage: %s mydestination domain", argv[0]);
+    mail_conf_read();
+    myfree(var_mydest);
+    var_mydest = mystrdup(argv[1]);
+    vstream_printf("mydestination=%s destination=%s %s\n", argv[1], argv[2],
+		   (rc = resolve_local(argv[2])) > 0 ? "YES" :
+		   rc == 0 ? "NO" : "ERROR");
+    vstream_fflush(VSTREAM_OUT);
+    return (0);
+}
+
+#endif