Attachment 2453 Details for Bug 2074 – Canonicalise addresses when CanonicaliseHostnames enabled

[patch] Canonicalise addresses when CanonicaliseHostnames enabled

canon-addr.diff (text/plain), 2.73 KB, created by Damien Miller on 2014-07-03 16:18:32 AEST

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Creator: Damien Miller

Created: 2014-07-03 16:18:32 AEST

Size: 2.73 KB

patch

obsolete

>diff --git ssh.c ssh.c
>index 17f6363..a92287f 100644
>--- ssh.c
>+++ ssh.c
>@@ -262,6 +262,61 @@ resolve_host(const char *name, int port, int logerr, char *cname, size_t clen)
> }
> 
> /*
>+ * Attempt to resolve a numeric host address / port to a single address.
>+ * Returns a canonical address string.
>+ * Returns NULL on failure.
>+ * NB. this function must operate with a options having undefined members.
>+ */
>+static struct addrinfo *
>+resolve_addr(const char *name, int port, char *caddr, size_t clen)
>+{
>+	char addr[NI_MAXHOST], strport[NI_MAXSERV];
>+	struct addrinfo hints, *res;
>+	int gaierr;
>+
>+	if (port <= 0)
>+		port = default_ssh_port();
>+	snprintf(strport, sizeof strport, "%u", port);
>+	memset(&hints, 0, sizeof(hints));
>+	hints.ai_family = options.address_family == -1 ?
>+	    AF_UNSPEC : options.address_family;
>+	hints.ai_socktype = SOCK_STREAM;
>+	hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV;
>+	if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) {
>+		debug2("%s: could not resolve name %.100s as address: %s",
>+		    __func__, name, ssh_gai_strerror(gaierr));
>+		return NULL;
>+	}
>+	if (res == NULL) {
>+		debug("%s: getaddrinfo %.100s returned no addresses",
>+		 __func__, name);
>+		return NULL;
>+	}
>+	if (res->ai_next != NULL) {
>+		debug("%s: getaddrinfo %.100s returned multiple addresses",
>+		    __func__, name);
>+		freeaddrinfo(res);
>+		return NULL;
>+	}
>+	if ((gaierr = getnameinfo(res->ai_addr, res->ai_addrlen,
>+	    addr, sizeof(addr), NULL, 0, NI_NUMERICHOST)) != 0) {
>+		debug("%s: Could not format address for name %.100s: %s",
>+		    __func__, name, ssh_gai_strerror(gaierr));
>+		freeaddrinfo(res);
>+		return NULL;
>+	}
>+	if (strlcpy(caddr, addr, clen) >= clen) {
>+		error("%s: host \"%s\" addr \"%s\" too long (max %lu)",
>+		    __func__, name,  addr, (u_long)clen);
>+		if (clen > 0)
>+			*caddr = '\0';
>+		freeaddrinfo(res);
>+		return NULL;
>+	}
>+	return res;
>+}
>+
>+/*
>  * Check whether the cname is a permitted replacement for the hostname
>  * and perform the replacement if it is.
>  * NB. this function must operate with a options having undefined members.
>@@ -325,6 +380,19 @@ resolve_canonicalize(char **hostp, int port)
> 	    options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS)
> 		return NULL;
> 
>+	/* Try numeric hostnames first */
>+	if ((addrs = resolve_addr(*hostp, port,
>+	    cname_target, sizeof(cname_target))) != NULL) {
>+		debug2("%s: hostname %.100s is address", __func__, *hostp);
>+		if (strcasecmp(*hostp, cname_target) != 0) {
>+			debug2("%s: canonicalised address \"%s\" => \"%s\"",
>+			    __func__, *hostp, cname_target);
>+			free(*hostp);
>+			*hostp = xstrdup(cname_target);
>+		}
>+		return addrs;
>+	}
>+
> 	/* Don't apply canonicalization to sufficiently-qualified hostnames */
> 	ndots = 0;
> 	for (cp = *hostp; *cp != '\0'; cp++) {

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Attachments on bug 2074: 2226 | 2453