Commit 6d740164 authored by Paulo Alcantara's avatar Paulo Alcantara Committed by Steve French
Browse files

cifs: set resolved ip in sockaddr 



All callers from dns_resolve_server_name_to_ip() used to convert the
ip addr string back to sockaddr, so do that inside
dns_resolve_server_name_to_ip() and avoid duplicating code.

Signed-off-by: default avatarPaulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 2301bc10

fs/cifs/connect.c

+12 −16
Original line number Diff line number Diff line
@@ -91,7 +91,8 @@ static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server) 
{

	int rc;

	int len;

	char *unc, *ipaddr = NULL;

	char *unc;

	struct sockaddr_storage ss;

	time64_t expiry, now;

	unsigned long ttl = SMB_DNS_RESOLVE_INTERVAL_DEFAULT;
@@ -111,7 +112,11 @@ static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server) 
	}

	scnprintf(unc, len, "\\\\%s", server->hostname);



	rc = dns_resolve_server_name_to_ip(unc, &ipaddr, &expiry);

	spin_lock(&server->srv_lock);

	ss = server->dstaddr;

	spin_unlock(&server->srv_lock);



	rc = dns_resolve_server_name_to_ip(unc, (struct sockaddr *)&ss, &expiry);

	kfree(unc);



	if (rc < 0) {
@@ -121,22 +126,13 @@ static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server) 
	}



	spin_lock(&server->srv_lock);

	rc = cifs_convert_address((struct sockaddr *)&server->dstaddr, ipaddr,

				  strlen(ipaddr));

	memcpy(&server->dstaddr, &ss, sizeof(server->dstaddr));

	spin_unlock(&server->srv_lock);

	kfree(ipaddr);



	/* rc == 1 means success here */

	if (rc) {

	now = ktime_get_real_seconds();

	if (expiry && expiry > now)

			/*

			 * To make sure we don't use the cached entry, retry 1s

			 * after expiry.

			 */

		/* To make sure we don't use the cached entry, retry 1s */

		ttl = max_t(unsigned long, expiry - now, SMB_DNS_RESOLVE_INTERVAL_MIN) + 1;

	}

	rc = !rc ? -1 : 0;



requeue_resolve:

	cifs_dbg(FYI, "%s: next dns resolution scheduled for %lu seconds in the future\n",

fs/cifs/dfs.c

+1 −23
Original line number Diff line number Diff line
@@ -9,28 +9,6 @@ 
#include "fs_context.h"

#include "dfs.h"



/* Resolve UNC server name and set destination ip address in fs context */

static int resolve_unc(const char *path, struct smb3_fs_context *ctx)

{

	int rc;

	char *ip = NULL;



	rc = dns_resolve_server_name_to_ip(path, &ip, NULL);

	if (rc < 0) {

		cifs_dbg(FYI, "%s: failed to resolve UNC server name: %d\n", __func__, rc);

		return rc;

	}



	if (!cifs_convert_address((struct sockaddr *)&ctx->dstaddr, ip, strlen(ip))) {

		cifs_dbg(VFS, "%s: could not determinate destination address\n", __func__);

		rc = -EHOSTUNREACH;

	} else

		rc = 0;



	kfree(ip);

	return rc;

}



/**

 * dfs_parse_target_referral - set fs context for dfs target referral

 *
@@ -68,7 +46,7 @@ int dfs_parse_target_referral(const char *full_path, const struct dfs_info3_para 
	if (rc)

		goto out;



	rc = resolve_unc(path, ctx);

	rc = dns_resolve_server_name_to_ip(path, (struct sockaddr *)&ctx->dstaddr, NULL);



out:

	kfree(path);

fs/cifs/dfs_cache.c

+5 −12
Original line number Diff line number Diff line
@@ -1314,8 +1314,7 @@ static bool target_share_equal(struct TCP_Server_Info *server, const char *s1, c 
	char unc[sizeof("\\\\") + SERVER_NAME_LENGTH] = {0};

	const char *host;

	size_t hostlen;

	char *ip = NULL;

	struct sockaddr sa;

	struct sockaddr_storage ss;

	bool match;

	int rc;
@@ -1330,23 +1329,17 @@ static bool target_share_equal(struct TCP_Server_Info *server, const char *s1, c 
	extract_unc_hostname(s1, &host, &hostlen);

	scnprintf(unc, sizeof(unc), "\\\\%.*s", (int)hostlen, host);



	rc = dns_resolve_server_name_to_ip(unc, &ip, NULL);

	rc = dns_resolve_server_name_to_ip(unc, (struct sockaddr *)&ss, NULL);

	if (rc < 0) {

		cifs_dbg(FYI, "%s: could not resolve %.*s. assuming server address matches.\n",

			 __func__, (int)hostlen, host);

		return true;

	}



	if (!cifs_convert_address(&sa, ip, strlen(ip))) {

		cifs_dbg(VFS, "%s: failed to convert address \'%s\'. skip address matching.\n",

			 __func__, ip);

	} else {

	cifs_server_lock(server);

		match = cifs_match_ipaddr((struct sockaddr *)&server->dstaddr, &sa);

	match = cifs_match_ipaddr((struct sockaddr *)&server->dstaddr, (struct sockaddr *)&ss);

	cifs_server_unlock(server);

	}



	kfree(ip);

	return match;

}

fs/cifs/dns_resolve.c

+24 −25
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ 
 *

 */



#include <linux/inet.h>

#include <linux/slab.h>

#include <linux/dns_resolver.h>

#include "dns_resolve.h"
@@ -25,17 +26,13 @@ 
 * @ip_addr: Where to return the IP address.

 * @expiry: Where to return the expiry time for the dns record.

 *

 * The IP address will be returned in string form, and the caller is

 * responsible for freeing it.

 *

 * Returns length of result on success, -ve on error.

 * Returns zero success, -ve on error.

 */

int

dns_resolve_server_name_to_ip(const char *unc, char **ip_addr, time64_t *expiry)

dns_resolve_server_name_to_ip(const char *unc, struct sockaddr *ip_addr, time64_t *expiry)

{

	struct sockaddr_storage ss;

	const char *hostname, *sep;

	char *name;

	char *ip;

	int len, rc;



	if (!ip_addr || !unc)
@@ -60,30 +57,32 @@ dns_resolve_server_name_to_ip(const char *unc, char **ip_addr, time64_t *expiry) 
			 __func__, unc);



	/* Try to interpret hostname as an IPv4 or IPv6 address */

	rc = cifs_convert_address((struct sockaddr *)&ss, hostname, len);

	if (rc > 0)

		goto name_is_IP_address;

	rc = cifs_convert_address(ip_addr, hostname, len);

	if (rc > 0) {

		cifs_dbg(FYI, "%s: unc is IP, skipping dns upcall: %*.*s\n", __func__, len, len,

			 hostname);

		return 0;

	}



	/* Perform the upcall */

	rc = dns_query(current->nsproxy->net_ns, NULL, hostname, len,

		       NULL, ip_addr, expiry, false);

	if (rc < 0)

		       NULL, &ip, expiry, false);

	if (rc < 0) {

		cifs_dbg(FYI, "%s: unable to resolve: %*.*s\n",

			 __func__, len, len, hostname);

	else

	} else {

		cifs_dbg(FYI, "%s: resolved: %*.*s to %s expiry %llu\n",

			 __func__, len, len, hostname, *ip_addr,

			 __func__, len, len, hostname, ip,

			 expiry ? (*expiry) : 0);

	return rc;



name_is_IP_address:

	name = kmalloc(len + 1, GFP_KERNEL);

	if (!name)

		return -ENOMEM;

	memcpy(name, hostname, len);

	name[len] = 0;

	cifs_dbg(FYI, "%s: unc is IP, skipping dns upcall: %s\n",

		 __func__, name);

	*ip_addr = name;

	return 0;

		rc = cifs_convert_address(ip_addr, ip, strlen(ip));

		kfree(ip);



		if (!rc) {

			cifs_dbg(FYI, "%s: unable to determine ip address\n", __func__);

			rc = -EHOSTUNREACH;

		} else

			rc = 0;

	}

	return rc;

}

fs/cifs/dns_resolve.h

+3 −1
Original line number Diff line number Diff line
@@ -11,8 +11,10 @@ 
#ifndef _DNS_RESOLVE_H

#define _DNS_RESOLVE_H



#include <linux/net.h>



#ifdef __KERNEL__

extern int dns_resolve_server_name_to_ip(const char *unc, char **ip_addr, time64_t *expiry);

int dns_resolve_server_name_to_ip(const char *unc, struct sockaddr *ip_addr, time64_t *expiry);

#endif /* KERNEL */



#endif /* _DNS_RESOLVE_H */