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-rw-r--r--src/util/cidr_match.c307
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diff --git a/src/util/cidr_match.c b/src/util/cidr_match.c
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+/*++
+/* NAME
+/* cidr_match 3
+/* SUMMARY
+/* CIDR-style pattern matching
+/* SYNOPSIS
+/* #include <cidr_match.h>
+/*
+/* VSTRING *cidr_match_parse(info, pattern, match, why)
+/* CIDR_MATCH *info;
+/* char *pattern;
+/* VSTRING *why;
+/*
+/* int cidr_match_execute(info, address)
+/* CIDR_MATCH *info;
+/* const char *address;
+/* AUXILIARY FUNCTIONS
+/* VSTRING *cidr_match_parse_if(info, pattern, match, why)
+/* CIDR_MATCH *info;
+/* char *pattern;
+/* VSTRING *why;
+/*
+/* void cidr_match_endif(info)
+/* CIDR_MATCH *info;
+/* DESCRIPTION
+/* This module parses address or address/length patterns and
+/* provides simple address matching. The implementation is
+/* such that parsing and execution can be done without dynamic
+/* memory allocation. The purpose is to minimize overhead when
+/* called by functions that parse and execute on the fly, such
+/* as match_hostaddr().
+/*
+/* cidr_match_parse() parses an address or address/mask
+/* expression and stores the result into the info argument.
+/* A non-zero (or zero) match argument requests a positive (or
+/* negative) match. The symbolic constants CIDR_MATCH_TRUE and
+/* CIDR_MATCH_FALSE may help to improve code readability.
+/* The result is non-zero in case of problems: either the
+/* value of the why argument, or a newly allocated VSTRING
+/* (the caller should give the latter to vstring_free()).
+/* The pattern argument is destroyed.
+/*
+/* cidr_match_parse_if() parses the address that follows an IF
+/* token, and stores the result into the info argument.
+/* The arguments are the same as for cidr_match_parse().
+/*
+/* cidr_match_endif() handles the occurrence of an ENDIF token,
+/* and updates the info argument.
+/*
+/* cidr_match_execute() matches the specified address against
+/* a list of parsed expressions, and returns the matching
+/* expression's data structure.
+/* SEE ALSO
+/* dict_cidr(3) CIDR-style lookup table
+/* 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 <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <ctype.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+/* Utility library. */
+
+#include <msg.h>
+#include <vstring.h>
+#include <stringops.h>
+#include <split_at.h>
+#include <myaddrinfo.h>
+#include <mask_addr.h>
+#include <cidr_match.h>
+
+/* Application-specific. */
+
+ /*
+ * This is how we figure out the address family, address bit count and
+ * address byte count for a CIDR_MATCH entry.
+ */
+#ifdef HAS_IPV6
+#define CIDR_MATCH_ADDR_FAMILY(a) (strchr((a), ':') ? AF_INET6 : AF_INET)
+#define CIDR_MATCH_ADDR_BIT_COUNT(f) \
+ ((f) == AF_INET6 ? MAI_V6ADDR_BITS : \
+ (f) == AF_INET ? MAI_V4ADDR_BITS : \
+ (msg_panic("%s: bad address family %d", myname, (f)), 0))
+#define CIDR_MATCH_ADDR_BYTE_COUNT(f) \
+ ((f) == AF_INET6 ? MAI_V6ADDR_BYTES : \
+ (f) == AF_INET ? MAI_V4ADDR_BYTES : \
+ (msg_panic("%s: bad address family %d", myname, (f)), 0))
+#else
+#define CIDR_MATCH_ADDR_FAMILY(a) (AF_INET)
+#define CIDR_MATCH_ADDR_BIT_COUNT(f) \
+ ((f) == AF_INET ? MAI_V4ADDR_BITS : \
+ (msg_panic("%s: bad address family %d", myname, (f)), 0))
+#define CIDR_MATCH_ADDR_BYTE_COUNT(f) \
+ ((f) == AF_INET ? MAI_V4ADDR_BYTES : \
+ (msg_panic("%s: bad address family %d", myname, (f)), 0))
+#endif
+
+/* cidr_match_entry - match one entry */
+
+static inline int cidr_match_entry(CIDR_MATCH *entry,
+ unsigned char *addr_bytes)
+{
+ unsigned char *mp;
+ unsigned char *np;
+ unsigned char *ap;
+
+ /* Unoptimized case: netmask with some or all bits zero. */
+ if (entry->mask_shift < entry->addr_bit_count) {
+ for (np = entry->net_bytes, mp = entry->mask_bytes,
+ ap = addr_bytes; /* void */ ; np++, mp++, ap++) {
+ if (ap >= addr_bytes + entry->addr_byte_count)
+ return (entry->match);
+ if ((*ap & *mp) != *np)
+ break;
+ }
+ }
+ /* Optimized case: all 1 netmask (i.e. no netmask specified). */
+ else {
+ for (np = entry->net_bytes,
+ ap = addr_bytes; /* void */ ; np++, ap++) {
+ if (ap >= addr_bytes + entry->addr_byte_count)
+ return (entry->match);
+ if (*ap != *np)
+ break;
+ }
+ }
+ return (!entry->match);
+}
+
+/* cidr_match_execute - match address against compiled CIDR pattern list */
+
+CIDR_MATCH *cidr_match_execute(CIDR_MATCH *list, const char *addr)
+{
+ unsigned char addr_bytes[CIDR_MATCH_ABYTES];
+ unsigned addr_family;
+ CIDR_MATCH *entry;
+
+ addr_family = CIDR_MATCH_ADDR_FAMILY(addr);
+ if (inet_pton(addr_family, addr, addr_bytes) != 1)
+ return (0);
+
+ for (entry = list; entry; entry = entry->next) {
+
+ switch (entry->op) {
+
+ case CIDR_MATCH_OP_MATCH:
+ if (entry->addr_family == addr_family)
+ if (cidr_match_entry(entry, addr_bytes))
+ return (entry);
+ break;
+
+ case CIDR_MATCH_OP_IF:
+ if (entry->addr_family == addr_family)
+ if (cidr_match_entry(entry, addr_bytes))
+ continue;
+ /* An IF without matching ENDIF has no end-of block entry. */
+ if ((entry = entry->block_end) == 0)
+ return (0);
+ /* FALLTHROUGH */
+
+ case CIDR_MATCH_OP_ENDIF:
+ continue;
+ }
+ }
+ return (0);
+}
+
+/* cidr_match_parse - parse CIDR pattern */
+
+VSTRING *cidr_match_parse(CIDR_MATCH *ip, char *pattern, int match,
+ VSTRING *why)
+{
+ const char *myname = "cidr_match_parse";
+ char *mask_search;
+ char *mask;
+ MAI_HOSTADDR_STR hostaddr;
+ unsigned char *np;
+ unsigned char *mp;
+
+ /*
+ * Strip [] from [addr/len] or [addr]/len, destroying the pattern. CIDR
+ * maps don't need [] to eliminate syntax ambiguity, but matchlists need
+ * it. While stripping [], figure out where we should start looking for
+ * /mask information.
+ */
+ if (*pattern == '[') {
+ pattern++;
+ if ((mask_search = split_at(pattern, ']')) == 0) {
+ vstring_sprintf(why ? why : (why = vstring_alloc(20)),
+ "missing ']' character after \"[%s\"", pattern);
+ return (why);
+ } else if (*mask_search != '/') {
+ if (*mask_search != 0) {
+ vstring_sprintf(why ? why : (why = vstring_alloc(20)),
+ "garbage after \"[%s]\"", pattern);
+ return (why);
+ }
+ mask_search = pattern;
+ }
+ } else
+ mask_search = pattern;
+
+ /*
+ * Parse the pattern into network and mask, destroying the pattern.
+ */
+ if ((mask = split_at(mask_search, '/')) != 0) {
+ ip->addr_family = CIDR_MATCH_ADDR_FAMILY(pattern);
+ ip->addr_bit_count = CIDR_MATCH_ADDR_BIT_COUNT(ip->addr_family);
+ ip->addr_byte_count = CIDR_MATCH_ADDR_BYTE_COUNT(ip->addr_family);
+ if (!alldig(mask)
+ || (ip->mask_shift = atoi(mask)) > ip->addr_bit_count
+ || inet_pton(ip->addr_family, pattern, ip->net_bytes) != 1) {
+ vstring_sprintf(why ? why : (why = vstring_alloc(20)),
+ "bad net/mask pattern: \"%s/%s\"", pattern, mask);
+ return (why);
+ }
+ if (ip->mask_shift > 0) {
+ /* Allow for bytes > 8. */
+ memset(ip->mask_bytes, ~0U, ip->addr_byte_count);
+ mask_addr(ip->mask_bytes, ip->addr_byte_count, ip->mask_shift);
+ } else
+ memset(ip->mask_bytes, 0, ip->addr_byte_count);
+
+ /*
+ * Sanity check: all host address bits must be zero.
+ */
+ for (np = ip->net_bytes, mp = ip->mask_bytes;
+ np < ip->net_bytes + ip->addr_byte_count; np++, mp++) {
+ if (*np & ~(*mp)) {
+ mask_addr(ip->net_bytes, ip->addr_byte_count, ip->mask_shift);
+ if (inet_ntop(ip->addr_family, ip->net_bytes, hostaddr.buf,
+ sizeof(hostaddr.buf)) == 0)
+ msg_fatal("inet_ntop: %m");
+ vstring_sprintf(why ? why : (why = vstring_alloc(20)),
+ "non-null host address bits in \"%s/%s\", "
+ "perhaps you should use \"%s/%d\" instead",
+ pattern, mask, hostaddr.buf, ip->mask_shift);
+ return (why);
+ }
+ }
+ }
+
+ /*
+ * No /mask specified. Treat a bare network address as /allbits.
+ */
+ else {
+ ip->addr_family = CIDR_MATCH_ADDR_FAMILY(pattern);
+ ip->addr_bit_count = CIDR_MATCH_ADDR_BIT_COUNT(ip->addr_family);
+ ip->addr_byte_count = CIDR_MATCH_ADDR_BYTE_COUNT(ip->addr_family);
+ if (inet_pton(ip->addr_family, pattern, ip->net_bytes) != 1) {
+ vstring_sprintf(why ? why : (why = vstring_alloc(20)),
+ "bad address pattern: \"%s\"", pattern);
+ return (why);
+ }
+ ip->mask_shift = ip->addr_bit_count;
+ /* Allow for bytes > 8. */
+ memset(ip->mask_bytes, ~0U, ip->addr_byte_count);
+ }
+
+ /*
+ * Wrap up the result.
+ */
+ ip->op = CIDR_MATCH_OP_MATCH;
+ ip->match = match;
+ ip->next = 0;
+ ip->block_end = 0;
+
+ return (0);
+}
+
+/* cidr_match_parse_if - parse CIDR pattern after IF */
+
+VSTRING *cidr_match_parse_if(CIDR_MATCH *ip, char *pattern, int match,
+ VSTRING *why)
+{
+ VSTRING *ret;
+
+ if ((ret = cidr_match_parse(ip, pattern, match, why)) == 0)
+ ip->op = CIDR_MATCH_OP_IF;
+ return (ret);
+}
+
+/* cidr_match_endif - handle ENDIF pattern */
+
+void cidr_match_endif(CIDR_MATCH *ip)
+{
+ memset(ip, 0, sizeof(*ip));
+ ip->op = CIDR_MATCH_OP_ENDIF;
+ ip->next = 0; /* maybe not all bits 0 */
+ ip->block_end = 0;
+}
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