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+/*++
+/* NAME
+/* match_ops 3
+/* SUMMARY
+/* simple string or host pattern matching
+/* SYNOPSIS
+/* #include <match_list.h>
+/*
+/* int match_string(list, string, pattern)
+/* MATCH_LIST *list;
+/* const char *string;
+/* const char *pattern;
+/*
+/* int match_hostname(list, name, pattern)
+/* MATCH_LIST *list;
+/* const char *name;
+/* const char *pattern;
+/*
+/* int match_hostaddr(list, addr, pattern)
+/* MATCH_LIST *list;
+/* const char *addr;
+/* const char *pattern;
+/* DESCRIPTION
+/* This module implements simple string and host name or address
+/* matching. The matching process is case insensitive. If a pattern
+/* has the form type:name, table lookup is used instead of string
+/* or address comparison.
+/*
+/* match_string() matches the string against the pattern, requiring
+/* an exact (case-insensitive) match. The flags argument is not used.
+/*
+/* match_hostname() matches the host name when the hostname matches
+/* the pattern exactly, or when the pattern matches a parent domain
+/* of the named host. The flags argument specifies the bit-wise OR
+/* of zero or more of the following:
+/* .IP MATCH_FLAG_PARENT
+/* The hostname pattern foo.com matches itself and any name below
+/* the domain foo.com. If this flag is cleared, foo.com matches itself
+/* only, and .foo.com matches any name below the domain foo.com.
+/* .IP MATCH_FLAG_RETURN
+/* Log a warning, return "not found", and set list->error to
+/* a non-zero dictionary error code, instead of raising a fatal
+/* run-time error.
+/* .RE
+/* Specify MATCH_FLAG_NONE to request none of the above.
+/*
+/* match_hostaddr() matches a host address when the pattern is
+/* identical to the host address, or when the pattern is a net/mask
+/* that contains the address. The mask specifies the number of
+/* bits in the network part of the pattern. The flags argument is
+/* not used.
+/* 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
+/*
+/* Wietse Venema
+/* Google, Inc.
+/* 111 8th Avenue
+/* New York, NY 10011, USA
+/*--*/
+
+/* System library. */
+
+#include <sys_defs.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <string.h>
+#include <stdlib.h>
+
+/* Utility library. */
+
+#include <msg.h>
+#include <mymalloc.h>
+#include <split_at.h>
+#include <dict.h>
+#include <match_list.h>
+#include <stringops.h>
+#include <cidr_match.h>
+
+#define MATCH_DICTIONARY(pattern) \
+ ((pattern)[0] != '[' && strchr((pattern), ':') != 0)
+
+/* match_error - return or raise fatal error */
+
+static int match_error(MATCH_LIST *list, const char *fmt,...)
+{
+ VSTRING *buf = vstring_alloc(100);
+ va_list ap;
+
+ /*
+ * Report, and maybe return.
+ */
+ va_start(ap, fmt);
+ vstring_vsprintf(buf, fmt, ap);
+ va_end(ap);
+ if (list->flags & MATCH_FLAG_RETURN) {
+ msg_warn("%s: %s", list->pname, vstring_str(buf));
+ } else {
+ msg_fatal("%s: %s", list->pname, vstring_str(buf));
+ }
+ vstring_free(buf);
+ return (0);
+}
+
+/* match_string - match a string literal */
+
+int match_string(MATCH_LIST *list, const char *string, const char *pattern)
+{
+ const char *myname = "match_string";
+ DICT *dict;
+
+ if (msg_verbose)
+ msg_info("%s: %s: %s ~? %s", myname, list->pname, string, pattern);
+
+ /*
+ * Try dictionary lookup: exact match.
+ */
+ if (MATCH_DICTIONARY(pattern)) {
+ if ((dict = dict_handle(pattern)) == 0)
+ msg_panic("%s: unknown dictionary: %s", myname, pattern);
+ if (dict_get(dict, string) != 0)
+ return (1);
+ if ((list->error = dict->error) != 0)
+ return (match_error(list, "%s:%s: table lookup problem",
+ dict->type, dict->name));
+ return (0);
+ }
+
+ /*
+ * Try an exact string match. Note that the string and pattern are
+ * already casefolded.
+ */
+ if (strcmp(string, pattern) == 0) {
+ return (1);
+ }
+
+ /*
+ * No match found.
+ */
+ return (0);
+}
+
+/* match_hostname - match a host by name */
+
+int match_hostname(MATCH_LIST *list, const char *name, const char *pattern)
+{
+ const char *myname = "match_hostname";
+ const char *pd;
+ const char *entry;
+ const char *next;
+ int match;
+ DICT *dict;
+
+ if (msg_verbose)
+ msg_info("%s: %s: %s ~? %s", myname, list->pname, name, pattern);
+
+ /*
+ * Try dictionary lookup: exact match and parent domains.
+ *
+ * Don't look up parent domain substrings with regexp maps etc.
+ */
+ if (MATCH_DICTIONARY(pattern)) {
+ if ((dict = dict_handle(pattern)) == 0)
+ msg_panic("%s: unknown dictionary: %s", myname, pattern);
+ match = 0;
+ for (entry = name; *entry != 0; entry = next) {
+ if (entry == name || (dict->flags & DICT_FLAG_FIXED)) {
+ match = (dict_get(dict, entry) != 0);
+ if (msg_verbose > 1)
+ msg_info("%s: %s: lookup %s:%s %s: %s",
+ myname, list->pname, dict->type, dict->name,
+ entry, match ? "found" : "notfound");
+ if (match != 0)
+ break;
+ if ((list->error = dict->error) != 0)
+ return (match_error(list, "%s:%s: table lookup problem",
+ dict->type, dict->name));
+ }
+ if ((next = strchr(entry + 1, '.')) == 0)
+ break;
+ if (list->flags & MATCH_FLAG_PARENT)
+ next += 1;
+ }
+ return (match);
+ }
+
+ /*
+ * Try an exact match with the host name. Note that the name and the
+ * pattern are already casefolded.
+ */
+ if (strcmp(name, pattern) == 0) {
+ return (1);
+ }
+
+ /*
+ * See if the pattern is a parent domain of the hostname. Note that the
+ * name and the pattern are already casefolded.
+ */
+ else {
+ if (list->flags & MATCH_FLAG_PARENT) {
+ pd = name + strlen(name) - strlen(pattern);
+ if (pd > name && pd[-1] == '.' && strcmp(pd, pattern) == 0)
+ return (1);
+ } else if (pattern[0] == '.') {
+ pd = name + strlen(name) - strlen(pattern);
+ if (pd > name && strcmp(pd, pattern) == 0)
+ return (1);
+ }
+ }
+ return (0);
+}
+
+/* match_hostaddr - match host by address */
+
+int match_hostaddr(MATCH_LIST *list, const char *addr, const char *pattern)
+{
+ const char *myname = "match_hostaddr";
+ char *saved_patt;
+ CIDR_MATCH match_info;
+ DICT *dict;
+ VSTRING *err;
+ int rc;
+
+ if (msg_verbose)
+ msg_info("%s: %s: %s ~? %s", myname, list->pname, addr, pattern);
+
+#define V4_ADDR_STRING_CHARS "01234567890."
+#define V6_ADDR_STRING_CHARS V4_ADDR_STRING_CHARS "abcdefABCDEF:"
+
+ if (addr[strspn(addr, V6_ADDR_STRING_CHARS)] != 0)
+ return (0);
+
+ /*
+ * Try dictionary lookup. This can be case insensitive.
+ */
+ if (MATCH_DICTIONARY(pattern)) {
+ if ((dict = dict_handle(pattern)) == 0)
+ msg_panic("%s: unknown dictionary: %s", myname, pattern);
+ if (dict_get(dict, addr) != 0)
+ return (1);
+ if ((list->error = dict->error) != 0)
+ return (match_error(list, "%s:%s: table lookup problem",
+ dict->type, dict->name));
+ return (0);
+ }
+
+ /*
+ * Try an exact match with the host address. Note that the address and
+ * pattern are already casefolded.
+ */
+ if (pattern[0] != '[') {
+ if (strcmp(addr, pattern) == 0)
+ return (1);
+ } else {
+ size_t addr_len = strlen(addr);
+
+ if (strncmp(addr, pattern + 1, addr_len) == 0
+ && strcmp(pattern + 1 + addr_len, "]") == 0)
+ return (1);
+ }
+
+ /*
+ * Light-weight tests before we get into expensive operations.
+ *
+ * - Don't bother matching IPv4 against IPv6. Postfix transforms
+ * IPv4-in-IPv6 to native IPv4 form when IPv4 support is enabled in
+ * Postfix; if not, then Postfix has no business dealing with IPv4
+ * addresses anyway.
+ *
+ * - Don't bother unless the pattern is either an IPv6 address or net/mask.
+ *
+ * We can safely skip IPv4 address patterns because their form is
+ * unambiguous and they did not match in the strcmp() calls above.
+ *
+ * XXX We MUST skip (parent) domain names, which may appear in NAMADR_LIST
+ * input, to avoid triggering false cidr_match_parse() errors.
+ *
+ * The last two conditions below are for backwards compatibility with
+ * earlier Postfix versions: don't abort with fatal errors on junk that
+ * was silently ignored (principle of least astonishment).
+ */
+ if (!strchr(addr, ':') != !strchr(pattern, ':')
+ || pattern[strcspn(pattern, ":/")] == 0
+ || pattern[strspn(pattern, V4_ADDR_STRING_CHARS)] == 0
+ || pattern[strspn(pattern, V6_ADDR_STRING_CHARS "[]/")] != 0)
+ return (0);
+
+ /*
+ * No escape from expensive operations: either we have a net/mask
+ * pattern, or we have an address that can have multiple valid
+ * representations (e.g., 0:0:0:0:0:0:0:1 versus ::1, etc.). The only way
+ * to find out if the address matches the pattern is to transform
+ * everything into to binary form, and to do the comparison there.
+ */
+ saved_patt = mystrdup(pattern);
+ err = cidr_match_parse(&match_info, saved_patt, CIDR_MATCH_TRUE,
+ (VSTRING *) 0);
+ myfree(saved_patt);
+ if (err != 0) {
+ list->error = DICT_ERR_RETRY;
+ rc = match_error(list, "%s", vstring_str(err));
+ vstring_free(err);
+ return (rc);
+ }
+ return (cidr_match_execute(&match_info, addr) != 0);
+}
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