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tcpd/tcp_wrappers_7.6-ipv6-host-match.patch

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---
hosts_access.c | 271 ++++++++++++++++++++++++++++++++++-----------------------
misc.c | 18 +++
tcpd.h | 2
3 files changed, 183 insertions(+), 108 deletions(-)
Index: tcp_wrappers_7.6/hosts_access.c
===================================================================
--- tcp_wrappers_7.6.orig/hosts_access.c
+++ tcp_wrappers_7.6/hosts_access.c
@@ -88,6 +88,10 @@ static int server_match();
static int client_match();
static int host_match();
static int string_match();
+static int masked_match();
+#ifdef INET6
+static void ipv6_mask();
+#endif
/* Size of logical line buffer. */
@@ -293,6 +297,74 @@ struct hosts_info *host;
return (match);
}
+static inline int
+host_info_ipv6addr(const struct host_info *host, struct in6_addr *addrbuf)
+{
+ /*
+ * In some cases we don't get the sockaddr, only the addr.
+ * We use inet_pton to convert it to its binary representation
+ * and match against that.
+ */
+ if (host->sin == NULL) {
+ if (host->addr == NULL || inet_pton(AF_INET6, host->addr, addrbuf) != 1)
+ return 0;
+
+ return 1;
+ } else
+ if (host->sin->ss_family == AF_INET6) {
+ *addrbuf = ((struct sockaddr_in6 *) host->sin)->sin6_addr;
+ return 1;
+ }
+ return 0;
+}
+
+static inline int
+token_ipv6addr_and_mask(char *tok, struct in6_addr *addrbuf, unsigned int *maskbits)
+{
+ char *cbr;
+ char *slash;
+
+ if (*tok != '[')
+ return 0;
+
+ *maskbits = 128;
+
+ ++tok; /* now points to the beginning of the IPv6 addr string */
+ if ((cbr = strchr(tok, ']')) == NULL) {
+ tcpd_warn("bad IP6 address specification");
+ return 0;
+ }
+ *cbr++ = '\0';
+
+ /*
+ * A /nnn prefix specifies how many bits of the address we
+ * need to check.
+ * Note, we support both [x::y/64] and [x::y]/64
+ */
+ if ((slash = strchr(tok, '/')) == NULL && *cbr == '/')
+ slash = cbr;
+
+ if (slash != NULL) {
+ int mask;
+
+ *slash++ = '\0';
+ mask = atoi(slash);
+ if (mask < 0 || mask > 128) {
+ tcpd_warn("bad IP6 prefix specification");
+ return 0;
+ }
+
+ *maskbits = mask;
+ }
+
+ if (inet_pton(AF_INET6, tok, addrbuf) != 1) {
+ tcpd_warn("bad IP6 address specification");
+ return 0;
+ }
+
+ return 1;
+}
+
/* host_match - match host name and/or address against pattern */
static int host_match(tok, host)
@@ -328,12 +400,68 @@ struct host_info *host;
} else if (STR_EQ(tok, "LOCAL")) { /* local: no dots in name */
char *name = eval_hostname(host);
return (strchr(name, '.') == 0 && HOSTNAME_KNOWN(name));
+ } else if (tok[0] == '[') { /* IPv6 address */
+#ifdef INET6
+ struct in6_addr match_addr, host_addr;
+ unsigned int mask = 128;
+
+ if (!host_info_ipv6addr(host, &host_addr))
+ return (NO);
+
+ if (!token_ipv6addr_and_mask(tok, &match_addr, &mask))
+ return (NO);
+
+ /*
+ * Zero the bits we're not interested in in both addresses
+ * then compare. Note that we take a copy of the host info
+ * in that case.
+ */
+ if (mask != 128) {
+ ipv6_mask(&match_addr, mask);
+ ipv6_mask(&host_addr, mask);
+ }
+ if (memcmp(&match_addr, &host_addr, sizeof(struct in6_addr)) == 0)
+ return (YES);
+#endif
+ return (NO);
+ } else if ((mask = split_at(tok, '/')) != 0) { /* net/mask */
+ return (masked_match(tok, mask, eval_hostaddr(host)));
} else { /* anything else */
- return (string_match(tok, eval_hostaddr(host))
- || (NOT_INADDR(tok) && string_match(tok, eval_hostname(host))));
+ return (string_match(tok, eval_hostaddr(host))
+ || (NOT_INADDR(tok) && string_match(tok, eval_hostname(host))));
}
}
+static int masked_match(net_tok, mask_tok, string)
+char *net_tok;
+char *mask_tok;
+char *string;
+{
+ unsigned long net;
+ unsigned long mask;
+ unsigned long addr;
+
+ /*
+ * Disallow forms other than dotted quad: the treatment that inet_addr()
+ * gives to forms with less than four components is inconsistent with the
+ * access control language. John P. Rouillard <rouilj@cs.umb.edu>.
+ */
+
+ if ((addr = dot_quad_addr(string)) == INADDR_NONE)
+ return (NO);
+ if ((net = dot_quad_addr(net_tok)) == INADDR_NONE
+ || ((mask = dot_quad_addr(mask_tok)) == INADDR_NONE
+ && strcmp(mask_tok, "255.255.255.255")
+ && (mask = prefix_to_netmask(mask_tok)) == INADDR_NONE
+ && strcmp(mask_tok, "32"))) {
+ /* 255.255.255.255 == INADDR_NONE, separate check needed. TJ. */
+ /* 32 == INADDR_NONE, separate check needed. philipp */
+ tcpd_warn("bad net/mask expression: %s/%s", net_tok, mask_tok);
+ return (NO); /* not tcpd_jump() */
+ }
+ return ((addr & mask) == net);
+}
+
/* string_match - match string against pattern
*
* tok = data read from /etc/hosts.*
@@ -359,113 +487,14 @@ char *string;
return (YES);
} else if (STR_EQ(tok, "KNOWN")) { /* not unknown */
return (STR_NE(string, unknown));
- } else if (STR_EQ(tok, string)) /* exact match */
- return (YES);
-#ifdef INET6
- else /* IP addresses match - not needed for IPv4 */
- {
- /* For simplicity we convert everything to IPv6 (or v4 mapped) */
- struct in6_addr pat, addr;
- int len, ret, prefixlen=128, nof_periods = 0;
- char ch, token[INET6_ADDRSTRLEN+1], *mask, *addition;
-
- /* If prefix was given, handle it */
- if ((mask = split_at(tok, '/')) != 0)
- {
- if (strchr(mask, '.') != NULL) /* We have something
- like 255.255.0.0 */
- {
- int b1, b2, b3, b4;
- uint32_t netmask;
-
- if (sscanf(mask, "%d.%d.%d.%d", &b1, &b2, &b3, &b4) != 4)
- {
- tcpd_warn ("Wrong netmask in %s", tok);
- return (NO);
- }
- netmask = (((((b1 * 256) + b2) * 256) + b3) * 256) + b4;
- prefixlen = 0;
- while (netmask > 0)
- {
- ++prefixlen;
- netmask <<= 1;
- }
- }
- else if (sscanf(mask, "%d", &prefixlen) != 1 || prefixlen < 0)
- {
- tcpd_warn ("Wrong prefix length in %s", tok);
- return (NO);
- }
-
- if (is_v4_string (tok))
- prefixlen += 96; /* extend to v4mapped */
-
- if (prefixlen > 128)
- {
- tcpd_warn ("Prefix too long in %s", tok);
- return (NO);
- }
- }
-
- len = strlen(tok);
- if (tok[len - 1] == '.') { /* prefix */
- char *ptok = tok;
-
- while ((ptok = strchr(ptok, '.')) != NULL){
- nof_periods++;
- ptok++;
- }
- switch(nof_periods){
- case 1:
- addition = "0.0.0";
- prefixlen = 8;
- break;
- case 2:
- addition = "0.0";
- prefixlen = 16;
- break;
- case 3:
- addition = "0";
- prefixlen = 24;
- break;
- default:
- tcpd_warn ("Wrong prefix %s", tok);
- return (NO);
- }
- snprintf(token, sizeof(token), "%s%s", tok, addition);
- prefixlen += 96; /* extend to v4mapped */
- }
- else if (*tok == '[' && tok[len - 1] == ']')
- {
- ch = tok[len - 1];
- tok[len - 1] = '\0';
- snprintf(token, sizeof(token), "%s", tok+1);
- tok[len - 1] = ch;
- }
- else
- snprintf(token, sizeof(token), "%s", tok);
-
- memset (&pat, 0, sizeof(pat));
- memset (&addr, 0, sizeof(addr));
-
- if (inet_pton_mapped(AF_INET6, token, &pat) != 1)
- return (NO);
-
- if (inet_pton_mapped(AF_INET6, string, &addr) != 1)
- {
- tcpd_warn("Unable to handle client address: %s", string);
- return (NO);
- }
-
- if (prefixlen < 128)
- {
- apply_v6_prefix (&pat, prefixlen);
- apply_v6_prefix (&addr, prefixlen);
- }
-
- return (!memcmp(&pat, &addr, sizeof(struct in6_addr)));
+ } else if (tok[(n = strlen(tok)) - 1] == '.') { /* prefix */
+ return (STRN_EQ(tok, string, n));
+ } else if ((STR_EQ(tok, "localhost") || STR_EQ(tok, "localhost.localdomain"))
+ && (STR_EQ(string, "localhost") || STR_EQ(string, "localhost.localdomain"))) {
+ return (YES); /* these localhosts are equivalent */
+ } else { /* exact match */
+ return (STR_EQ(tok, string));
}
-#endif
}
#ifndef DISABLE_WILDCARD_MATCHING
@@ -535,3 +564,29 @@ int match_pattern_ylo(const char *s, con
/*NOTREACHED*/
}
#endif /* DISABLE_WILDCARD_MATCHING */
+
+#ifdef INET6
+/*
+ * Function that zeros all but the first "maskbits" bits of the IPV6 address
+ * This function can be made generic by specifying an address length as
+ * extra parameter. (So Wietse can implement 1.2.3.4/16)
+ */
+static void ipv6_mask(in6p, maskbits)
+struct in6_addr *in6p;
+int maskbits;
+{
+ unsigned char *p = (unsigned char*) in6p;
+
+ if (maskbits < 0 || maskbits >= 128)
+ return;
+
+ p += maskbits / 8;
+ maskbits %= 8;
+
+ if (maskbits != 0)
+ *p++ &= 0xff << (8 - maskbits);
+
+ while (p < (((unsigned char*) in6p)) + sizeof(*in6p))
+ *p++ = 0;
+}
+#endif
Index: tcp_wrappers_7.6/misc.c
===================================================================
--- tcp_wrappers_7.6.orig/misc.c
+++ tcp_wrappers_7.6/misc.c
@@ -107,3 +107,21 @@ char *str;
}
return (runs == 4 ? inet_addr(str) : INADDR_NONE);
}
+
+/* prefix_to_netmask - convert prefix (0-32) to netmask */
+
+unsigned long prefix_to_netmask(str)
+char *str;
+{
+ unsigned long prefix;
+ char *endptr;
+
+ if (!isdigit(str[0]))
+ return INADDR_NONE;
+
+ prefix = strtoul(str, &endptr, 10);
+ if ((endptr == str) || (*endptr != '\0') || (prefix > 32))
+ return INADDR_NONE;
+
+ return htonl(~0UL << (32 - prefix));
+}
Index: tcp_wrappers_7.6/tcpd.h
===================================================================
--- tcp_wrappers_7.6.orig/tcpd.h
+++ tcp_wrappers_7.6/tcpd.h
@@ -88,6 +88,7 @@ extern void refuse(struct request_info *
extern char *xgets(char *, int, FILE *);
extern char *split_at(char *, int);
extern unsigned long dot_quad_addr(char *);
+extern char *skip_ipv6_addrs(char *);
#else
extern int hosts_access(); /* access control */
extern void shell_cmd(); /* execute shell command */
@@ -98,6 +99,7 @@ extern void refuse(); /* clean up and
extern char *xgets(); /* fgets() on steroids */
extern char *split_at(); /* strchr() and split */
extern unsigned long dot_quad_addr(); /* restricted inet_addr() */
+extern char *skip_ipv6_addrs();
#endif
/* Global variables. */
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