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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: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
This commit is contained in:
Paulo Alcantara 2022-10-04 18:41:36 -03:00 committed by Steve French
parent 2301bc103a
commit 6d740164d8
6 changed files with 56 additions and 104 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
fs/cifs/connect.c
View File

@ -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.
*/
ttl = max_t(unsigned long, expiry - now, SMB_DNS_RESOLVE_INTERVAL_MIN) + 1;
}
rc = !rc ? -1 : 0;
now = ktime_get_real_seconds();
if (expiry && expiry > now)
/* 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;
requeue_resolve:
cifs_dbg(FYI, "%s: next dns resolution scheduled for %lu seconds in the future\n",

24
fs/cifs/dfs.c
View File

@ -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);

17
fs/cifs/dfs_cache.c
View File

@ -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);
cifs_server_unlock(server);
}
cifs_server_lock(server);
match = cifs_match_ipaddr((struct sockaddr *)&server->dstaddr, (struct sockaddr *)&ss);
cifs_server_unlock(server);
kfree(ip);
return match;
}

49
fs/cifs/dns_resolve.c
View File

@ -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;
}

4
fs/cifs/dns_resolve.h
View File

@ -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 */

38
fs/cifs/misc.c
View File

@ -1258,44 +1258,28 @@ int match_target_ip(struct TCP_Server_Info *server,
bool *result)
{
int rc;
char *target, *tip = NULL;
struct sockaddr tipaddr;
char *target;
struct sockaddr_storage ss;
*result = false;
target = kzalloc(share_len + 3, GFP_KERNEL);
if (!target) {
rc = -ENOMEM;
goto out;
}
if (!target)
return -ENOMEM;
scnprintf(target, share_len + 3, "\\\\%.*s", (int)share_len, share);
cifs_dbg(FYI, "%s: target name: %s\n", __func__, target + 2);
rc = dns_resolve_server_name_to_ip(target, &tip, NULL);
if (rc < 0)
goto out;
cifs_dbg(FYI, "%s: target ip: %s\n", __func__, tip);
if (!cifs_convert_address(&tipaddr, tip, strlen(tip))) {
cifs_dbg(VFS, "%s: failed to convert target ip address\n",
__func__);
rc = -EINVAL;
goto out;
}
*result = cifs_match_ipaddr((struct sockaddr *)&server->dstaddr,
&tipaddr);
cifs_dbg(FYI, "%s: ip addresses match: %u\n", __func__, *result);
rc = 0;
out:
rc = dns_resolve_server_name_to_ip(target, (struct sockaddr *)&ss, NULL);
kfree(target);
kfree(tip);
return rc;
if (rc < 0)
return rc;
*result = cifs_match_ipaddr((struct sockaddr *)&server->dstaddr, (struct sockaddr *)&ss);
cifs_dbg(FYI, "%s: ip addresses match: %u\n", __func__, *result);
return 0;
}
int cifs_update_super_prepath(struct cifs_sb_info *cifs_sb, char *prefix)