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-rw-r--r--src/global/mynetworks.c336
1 files changed, 336 insertions, 0 deletions
diff --git a/src/global/mynetworks.c b/src/global/mynetworks.c
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+/*++
+/* NAME
+/* mynetworks 3
+/* SUMMARY
+/* generate patterns for my own interface addresses
+/* SYNOPSIS
+/* #include <mynetworks.h>
+/*
+/* const char *mynetworks()
+/* AUXILIARY FUNCTIONS
+/* const char *mynetworks_host()
+/* DESCRIPTION
+/* This routine uses the address list built by own_inet_addr()
+/* to produce a list of patterns that match the corresponding
+/* networks.
+/*
+/* The interface list is specified with the "inet_interfaces"
+/* configuration parameter.
+/*
+/* The address to netblock conversion style is specified with
+/* the "mynetworks_style" parameter: one of "class" (match
+/* whole class A, B, C or D networks), "subnet" (match local
+/* subnets), or "host" (match local interfaces only).
+/*
+/* mynetworks_host() uses the "host" style.
+/* 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
+/*
+/* Dean C. Strik
+/* Department ICT Services
+/* Eindhoven University of Technology
+/* P.O. Box 513
+/* 5600 MB Eindhoven, Netherlands
+/* E-mail: <dean@ipnet6.org>
+/*--*/
+
+/* System library. */
+
+#include <sys_defs.h>
+#include <sys/param.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+#ifndef IN_CLASSD_NET
+#define IN_CLASSD_NET 0xf0000000
+#define IN_CLASSD_NSHIFT 28
+#endif
+
+/* Utility library. */
+
+#include <msg.h>
+#include <vstring.h>
+#include <inet_addr_list.h>
+#include <name_mask.h>
+#include <myaddrinfo.h>
+#include <mask_addr.h>
+#include <argv.h>
+#include <inet_proto.h>
+#include <mymalloc.h>
+
+/* Global library. */
+
+#include <own_inet_addr.h>
+#include <mail_params.h>
+#include <mynetworks.h>
+#include <sock_addr.h>
+#include <been_here.h>
+
+/* Application-specific. */
+
+#define MASK_STYLE_CLASS (1 << 0)
+#define MASK_STYLE_SUBNET (1 << 1)
+#define MASK_STYLE_HOST (1 << 2)
+
+static const NAME_MASK mask_styles[] = {
+ MYNETWORKS_STYLE_CLASS, MASK_STYLE_CLASS,
+ MYNETWORKS_STYLE_SUBNET, MASK_STYLE_SUBNET,
+ MYNETWORKS_STYLE_HOST, MASK_STYLE_HOST,
+ 0,
+};
+
+/* mynetworks_core - return patterns for specific mynetworks style */
+
+static const char *mynetworks_core(const char *style)
+{
+ const char *myname = "mynetworks_core";
+ VSTRING *result;
+ INET_ADDR_LIST *my_addr_list;
+ INET_ADDR_LIST *my_mask_list;
+ unsigned shift;
+ unsigned junk;
+ int i;
+ unsigned mask_style;
+ struct sockaddr_storage *sa;
+ struct sockaddr_storage *ma;
+ int net_mask_count = 0;
+ ARGV *argv;
+ BH_TABLE *dup_filter;
+ char **cpp;
+
+ /*
+ * Avoid run-time errors when all network protocols are disabled. We
+ * can't look up interface information, and we can't convert explicit
+ * names or addresses.
+ */
+ if (inet_proto_info()->ai_family_list[0] == 0) {
+ if (msg_verbose)
+ msg_info("skipping %s setting - "
+ "all network protocols are disabled",
+ VAR_MYNETWORKS);
+ return (mystrdup(""));
+ }
+ mask_style = name_mask("mynetworks mask style", mask_styles, style);
+
+ /*
+ * XXX Workaround: name_mask() needs a flags argument so that we can
+ * require exactly one value, or we need to provide an API that is
+ * dedicated for single-valued flags.
+ *
+ * XXX Why not use name_code() instead?
+ */
+ for (i = 0, junk = mask_style; junk != 0; junk >>= 1U)
+ i += (junk & 1);
+ if (i != 1)
+ msg_fatal("bad %s value: %s; specify exactly one value",
+ VAR_MYNETWORKS_STYLE, var_mynetworks_style);
+
+ result = vstring_alloc(20);
+ my_addr_list = own_inet_addr_list();
+ my_mask_list = own_inet_mask_list();
+
+ for (sa = my_addr_list->addrs, ma = my_mask_list->addrs;
+ sa < my_addr_list->addrs + my_addr_list->used;
+ sa++, ma++) {
+ unsigned long addr;
+ unsigned long mask;
+ struct in_addr net;
+
+ if (SOCK_ADDR_FAMILY(sa) == AF_INET) {
+ addr = ntohl(SOCK_ADDR_IN_ADDR(sa).s_addr);
+ mask = ntohl(SOCK_ADDR_IN_ADDR(ma).s_addr);
+
+ switch (mask_style) {
+
+ /*
+ * Natural mask. This is dangerous if you're customer of an
+ * ISP who gave you a small portion of their network.
+ */
+ case MASK_STYLE_CLASS:
+ if (IN_CLASSA(addr)) {
+ mask = IN_CLASSA_NET;
+ shift = IN_CLASSA_NSHIFT;
+ } else if (IN_CLASSB(addr)) {
+ mask = IN_CLASSB_NET;
+ shift = IN_CLASSB_NSHIFT;
+ } else if (IN_CLASSC(addr)) {
+ mask = IN_CLASSC_NET;
+ shift = IN_CLASSC_NSHIFT;
+ } else if (IN_CLASSD(addr)) {
+ mask = IN_CLASSD_NET;
+ shift = IN_CLASSD_NSHIFT;
+ } else {
+ msg_fatal("%s: unknown address class: %s",
+ myname, inet_ntoa(SOCK_ADDR_IN_ADDR(sa)));
+ }
+ break;
+
+ /*
+ * Subnet mask. This is less unsafe, but still bad if you're
+ * connected to a large subnet.
+ */
+ case MASK_STYLE_SUBNET:
+ for (junk = mask, shift = MAI_V4ADDR_BITS; junk != 0;
+ shift--, junk <<= 1)
+ /* void */ ;
+ break;
+
+ /*
+ * Host only. Do not relay authorize other hosts.
+ */
+ case MASK_STYLE_HOST:
+ mask = ~0UL;
+ shift = 0;
+ break;
+
+ default:
+ msg_panic("unknown mynetworks mask style: %s",
+ var_mynetworks_style);
+ }
+ net.s_addr = htonl(addr & mask);
+ vstring_sprintf_append(result, "%s/%d ",
+ inet_ntoa(net), MAI_V4ADDR_BITS - shift);
+ net_mask_count++;
+ continue;
+ }
+#ifdef HAS_IPV6
+ else if (SOCK_ADDR_FAMILY(sa) == AF_INET6) {
+ MAI_HOSTADDR_STR hostaddr;
+ unsigned char *ac;
+ unsigned char *end;
+ unsigned char ch;
+ struct sockaddr_in6 net6;
+
+ switch (mask_style) {
+
+ /*
+ * There are no classes for IPv6. We default to subnets
+ * instead.
+ */
+ case MASK_STYLE_CLASS:
+
+ /* FALLTHROUGH */
+
+ /*
+ * Subnet mask.
+ */
+ case MASK_STYLE_SUBNET:
+ ac = (unsigned char *) &SOCK_ADDR_IN6_ADDR(ma);
+ end = ac + sizeof(SOCK_ADDR_IN6_ADDR(ma));
+ shift = MAI_V6ADDR_BITS;
+ while (ac < end) {
+ if ((ch = *ac++) == (unsigned char) ~0U) {
+ shift -= CHAR_BIT;
+ continue;
+ } else {
+ while (ch != 0)
+ shift--, ch <<= 1;
+ break;
+ }
+ }
+ break;
+
+ /*
+ * Host only. Do not relay authorize other hosts.
+ */
+ case MASK_STYLE_HOST:
+ shift = 0;
+ break;
+
+ default:
+ msg_panic("unknown mynetworks mask style: %s",
+ var_mynetworks_style);
+ }
+ /* FIX 200501: IPv6 patch did not clear host bits. */
+ net6 = *SOCK_ADDR_IN6_PTR(sa);
+ mask_addr((unsigned char *) &net6.sin6_addr,
+ sizeof(net6.sin6_addr),
+ MAI_V6ADDR_BITS - shift);
+ SOCKADDR_TO_HOSTADDR(SOCK_ADDR_PTR(&net6), SOCK_ADDR_LEN(&net6),
+ &hostaddr, (MAI_SERVPORT_STR *) 0, 0);
+ vstring_sprintf_append(result, "[%s]/%d ",
+ hostaddr.buf, MAI_V6ADDR_BITS - shift);
+ net_mask_count++;
+ continue;
+ }
+#endif
+ else {
+ msg_warn("%s: skipping unknown address family %d",
+ myname, SOCK_ADDR_FAMILY(sa));
+ continue;
+ }
+ }
+
+ /*
+ * FIX 200501 IPv6 patch produced repeated results. Some systems report
+ * the same interface multiple times, notably multi-homed systems with
+ * IPv6 link-local or site-local addresses. A straight-forward sort+uniq
+ * produces ugly results, though. Instead we preserve the original order
+ * and use a duplicate filter to suppress repeated information.
+ */
+ if (net_mask_count > 1) {
+ argv = argv_split(vstring_str(result), " ");
+ VSTRING_RESET(result);
+ dup_filter = been_here_init(net_mask_count, BH_FLAG_NONE);
+ for (cpp = argv->argv; cpp < argv->argv + argv->argc; cpp++)
+ if (!been_here_fixed(dup_filter, *cpp))
+ vstring_sprintf_append(result, "%s ", *cpp);
+ argv_free(argv);
+ been_here_free(dup_filter);
+ }
+ if (msg_verbose)
+ msg_info("%s: %s", myname, vstring_str(result));
+ return (vstring_export(result));
+}
+
+/* mynetworks - return patterns that match my own networks */
+
+const char *mynetworks(void)
+{
+ static const char *result;
+
+ if (result == 0)
+ result = mynetworks_core(var_mynetworks_style);
+ return (result);
+}
+
+/* mynetworks_host - return patterns for "host" mynetworks style */
+
+const char *mynetworks_host(void)
+{
+ static const char *result;
+
+ if (result == 0)
+ result = mynetworks_core(MYNETWORKS_STYLE_HOST);
+ return (result);
+}
+
+#ifdef TEST
+#include <inet_proto.h>
+
+char *var_inet_interfaces;
+char *var_mynetworks_style;
+
+int main(int argc, char **argv)
+{
+ INET_PROTO_INFO *proto_info;
+
+ if (argc != 4)
+ msg_fatal("usage: %s protocols mask_style interface_list (e.g. \"all subnet all\")",
+ argv[0]);
+ msg_verbose = 10;
+ proto_info = inet_proto_init(argv[0], argv[1]);
+ var_mynetworks_style = argv[2];
+ var_inet_interfaces = argv[3];
+ mynetworks();
+ return (0);
+}
+
+#endif
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