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-rw-r--r--src/util/inet_proto.c323
1 files changed, 323 insertions, 0 deletions
diff --git a/src/util/inet_proto.c b/src/util/inet_proto.c
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+/*++
+/* NAME
+/* inet_proto 3
+/* SUMMARY
+/* convert protocol names to assorted constants
+/* SYNOPSIS
+/* #include <inet_proto.h>
+/*
+/* typedef struct {
+/* .in +4
+/* unsigned ai_family; /* PF_UNSPEC, PF_INET, or PF_INET6 */
+/* unsigned *ai_family_list; /* PF_INET and/or PF_INET6 */
+/* unsigned *dns_atype_list;/* TAAAA and/or TA */
+/* unsigned char *sa_family_list;/* AF_INET6 and/or AF_INET */
+/* .in -4
+/* } INET_PROTO_INFO;
+/*
+/* INET_PROTO_INFO *inet_proto_init(context, protocols)
+/*
+/* INET_PROTO_INFO *inet_proto_info()
+/* DESCRIPTION
+/* inet_proto_init() converts a string with protocol names
+/* into null-terminated lists of appropriate constants used
+/* by Postfix library routines. The idea is that one should
+/* be able to configure an MTA for IPv4 only, without having
+/* to recompile code (what a concept).
+/*
+/* Unfortunately, some compilers won't link initialized data
+/* without a function call into the same source module, so
+/* we invoke inet_proto_info() in order to access the result
+/* from inet_proto_init() from within library routines.
+/* inet_proto_info() also conveniently initializes the data
+/* to built-in defaults.
+/*
+/* Arguments:
+/* .IP context
+/* Typically, a configuration parameter name.
+/* .IP protocols
+/* Null-terminated string with protocol names separated by
+/* whitespace and/or commas:
+/* .RS
+/* .IP INET_PROTO_NAME_ALL
+/* Enable all available IP protocols.
+/* .IP INET_PROTO_NAME_IPV4
+/* Enable IP version 4 support.
+/* .IP INET_PROTO_NAME_IPV6
+/* Enable IP version 6 support.
+/* .RS
+/* .PP
+/* Results:
+/* .IP ai_family
+/* Only one of PF_UNSPEC, PF_INET, or PF_INET6. This can be
+/* used as input for the getaddrinfo() and getnameinfo()
+/* routines.
+/* .IP ai_family_list
+/* One or more of PF_INET or PF_INET6. This can be used as
+/* input for the inet_addr_local() routine.
+/* .IP dns_atype_list
+/* One or more of T_AAAA or T_A. This can be used as input for
+/* the dns_lookup_v() and dns_lookup_l() routines.
+/* .IP sa_family_list
+/* One or more of AF_INET6 or AF_INET. This can be used as an
+/* output filter for the results from the getaddrinfo() and
+/* getnameinfo() routines.
+/* SEE ALSO
+/* msg(3) diagnostics interface
+/* DIAGNOSTICS
+/* This module will warn and turn off support for any protocol
+/* that is requested but unavailable.
+/*
+/* Fatal errors: memory allocation problem.
+/* 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>
+#include <netinet/in.h>
+#include <arpa/nameser.h>
+#ifdef RESOLVE_H_NEEDS_STDIO_H
+#include <stdio.h>
+#endif
+#include <resolv.h>
+#include <stdarg.h>
+#include <unistd.h>
+
+/* Utility library. */
+
+#include <mymalloc.h>
+#include <msg.h>
+#include <myaddrinfo.h>
+#include <name_mask.h>
+#include <inet_proto.h>
+
+ /*
+ * Application-specific.
+ */
+
+ /*
+ * Run-time initialization, so we can work around LINUX where IPv6 falls
+ * flat on its face because it is not turned on in the kernel.
+ */
+INET_PROTO_INFO *inet_proto_table = 0;
+
+ /*
+ * Infrastructure: lookup table with the protocol names that we support.
+ */
+#define INET_PROTO_MASK_IPV4 (1<<0)
+#define INET_PROTO_MASK_IPV6 (1<<1)
+
+static const NAME_MASK proto_table[] = {
+#ifdef HAS_IPV6
+ INET_PROTO_NAME_ALL, INET_PROTO_MASK_IPV4 | INET_PROTO_MASK_IPV6,
+ INET_PROTO_NAME_IPV6, INET_PROTO_MASK_IPV6,
+#else
+ INET_PROTO_NAME_ALL, INET_PROTO_MASK_IPV4,
+#endif
+ INET_PROTO_NAME_IPV4, INET_PROTO_MASK_IPV4,
+ 0,
+};
+
+/* make_uchar_vector - create and initialize uchar vector */
+
+static unsigned char *make_uchar_vector(int len,...)
+{
+ const char *myname = "make_uchar_vector";
+ va_list ap;
+ int count;
+ unsigned char *vp;
+
+ va_start(ap, len);
+ if (len <= 0)
+ msg_panic("%s: bad vector length: %d", myname, len);
+ vp = (unsigned char *) mymalloc(sizeof(*vp) * len);
+ for (count = 0; count < len; count++)
+ vp[count] = va_arg(ap, unsigned);
+ va_end(ap);
+ return (vp);
+}
+
+/* make_unsigned_vector - create and initialize integer vector */
+
+static unsigned *make_unsigned_vector(int len,...)
+{
+ const char *myname = "make_unsigned_vector";
+ va_list ap;
+ int count;
+ unsigned *vp;
+
+ va_start(ap, len);
+ if (len <= 0)
+ msg_panic("%s: bad vector length: %d", myname, len);
+ vp = (unsigned *) mymalloc(sizeof(*vp) * len);
+ for (count = 0; count < len; count++)
+ vp[count] = va_arg(ap, unsigned);
+ va_end(ap);
+ return (vp);
+}
+
+/* inet_proto_free - destroy data */
+
+static void inet_proto_free(INET_PROTO_INFO *pf)
+{
+ myfree((void *) pf->ai_family_list);
+ myfree((void *) pf->dns_atype_list);
+ myfree((void *) pf->sa_family_list);
+ myfree((void *) pf);
+}
+
+/* inet_proto_init - convert protocol names to library inputs */
+
+INET_PROTO_INFO *inet_proto_init(const char *context, const char *protocols)
+{
+ const char *myname = "inet_proto";
+ INET_PROTO_INFO *pf;
+ int inet_proto_mask;
+ int sock;
+
+ /*
+ * 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.
+ */
+ inet_proto_mask = name_mask(context, proto_table, protocols);
+#ifdef HAS_IPV6
+ if (inet_proto_mask & INET_PROTO_MASK_IPV6) {
+ if ((sock = socket(PF_INET6, SOCK_STREAM, 0)) >= 0) {
+ close(sock);
+ } else if (errno == EAFNOSUPPORT || errno == EPROTONOSUPPORT) {
+ msg_warn("%s: disabling IPv6 name/address support: %m", context);
+ inet_proto_mask &= ~INET_PROTO_MASK_IPV6;
+ } else {
+ msg_fatal("socket: %m");
+ }
+ }
+#endif
+ if (inet_proto_mask & INET_PROTO_MASK_IPV4) {
+ if ((sock = socket(PF_INET, SOCK_STREAM, 0)) >= 0) {
+ close(sock);
+ } else if (errno == EAFNOSUPPORT || errno == EPROTONOSUPPORT) {
+ msg_warn("%s: disabling IPv4 name/address support: %m", context);
+ inet_proto_mask &= ~INET_PROTO_MASK_IPV4;
+ } else {
+ msg_fatal("socket: %m");
+ }
+ }
+
+ /*
+ * Store address family etc. info as null-terminated vectors. If that
+ * breaks because we must be able to store nulls, we'll deal with the
+ * additional complexity.
+ *
+ * XXX Use compile-time initialized data templates instead of building the
+ * reply on the fly.
+ */
+ switch (inet_proto_mask) {
+#ifdef HAS_IPV6
+ case INET_PROTO_MASK_IPV6:
+ pf = (INET_PROTO_INFO *) mymalloc(sizeof(*pf));
+ pf->ai_family = PF_INET6;
+ pf->ai_family_list = make_unsigned_vector(2, PF_INET6, 0);
+ pf->dns_atype_list = make_unsigned_vector(2, T_AAAA, 0);
+ pf->sa_family_list = make_uchar_vector(2, AF_INET6, 0);
+ break;
+ case (INET_PROTO_MASK_IPV6 | INET_PROTO_MASK_IPV4):
+ pf = (INET_PROTO_INFO *) mymalloc(sizeof(*pf));
+ pf->ai_family = PF_UNSPEC;
+ pf->ai_family_list = make_unsigned_vector(3, PF_INET, PF_INET6, 0);
+ pf->dns_atype_list = make_unsigned_vector(3, T_A, T_AAAA, 0);
+ pf->sa_family_list = make_uchar_vector(3, AF_INET, AF_INET6, 0);
+ break;
+#endif
+ case INET_PROTO_MASK_IPV4:
+ pf = (INET_PROTO_INFO *) mymalloc(sizeof(*pf));
+ pf->ai_family = PF_INET;
+ pf->ai_family_list = make_unsigned_vector(2, PF_INET, 0);
+ pf->dns_atype_list = make_unsigned_vector(2, T_A, 0);
+ pf->sa_family_list = make_uchar_vector(2, AF_INET, 0);
+ break;
+ case 0:
+ pf = (INET_PROTO_INFO *) mymalloc(sizeof(*pf));
+ pf->ai_family = PF_UNSPEC;
+ pf->ai_family_list = make_unsigned_vector(1, 0);
+ pf->dns_atype_list = make_unsigned_vector(1, 0);
+ pf->sa_family_list = make_uchar_vector(1, 0);
+ break;
+ default:
+ msg_panic("%s: bad inet_proto_mask 0x%x", myname, inet_proto_mask);
+ }
+ if (inet_proto_table)
+ inet_proto_free(inet_proto_table);
+ return (inet_proto_table = pf);
+}
+
+#ifdef TEST
+
+ /*
+ * Small driver for unit tests.
+ */
+
+static char *print_unsigned_vector(VSTRING *buf, unsigned *vector)
+{
+ unsigned *p;
+
+ VSTRING_RESET(buf);
+ for (p = vector; *p; p++) {
+ vstring_sprintf_append(buf, "%u", *p);
+ if (p[1])
+ VSTRING_ADDCH(buf, ' ');
+ }
+ VSTRING_TERMINATE(buf);
+ return (vstring_str(buf));
+}
+
+static char *print_uchar_vector(VSTRING *buf, unsigned char *vector)
+{
+ unsigned char *p;
+
+ VSTRING_RESET(buf);
+ for (p = vector; *p; p++) {
+ vstring_sprintf_append(buf, "%u", *p);
+ if (p[1])
+ VSTRING_ADDCH(buf, ' ');
+ }
+ VSTRING_TERMINATE(buf);
+ return (vstring_str(buf));
+}
+
+int main(int argc, char **argv)
+{
+ const char *myname = argv[0];
+ INET_PROTO_INFO *pf;
+ VSTRING *buf;
+
+ if (argc < 2)
+ msg_fatal("usage: %s protocol(s)...", myname);
+
+ buf = vstring_alloc(10);
+ while (*++argv) {
+ msg_info("=== %s ===", *argv);
+ inet_proto_init(myname, *argv);
+ pf = inet_proto_table;
+ msg_info("ai_family = %u", pf->ai_family);
+ msg_info("ai_family_list = %s",
+ print_unsigned_vector(buf, pf->ai_family_list));
+ msg_info("dns_atype_list = %s",
+ print_unsigned_vector(buf, pf->dns_atype_list));
+ msg_info("sa_family_list = %s",
+ print_uchar_vector(buf, pf->sa_family_list));
+ }
+ vstring_free(buf);
+ return (0);
+}
+
+#endif
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