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From: Jeff Layton on 22 Jul 2010 13:50
On Thu, 22 Jul 2010 18:33:01 +0100
David Howells <dhowells(a)redhat.com> wrote:

> Make cifs_convert_address() take a const src pointer and a length so that all
> the strlen() calls in their can be cut out and to make it unnecessary to modify
> the src string.
>
> Also return the data length from dns_resolve_server_name_to_ip() so that a
> strlen() can be cut out of cifs_compose_mount_options() too.
>
> Signed-off-by: David Howells <dhowells(a)redhat.com>
> ---
>
> fs/cifs/cifs_dfs_ref.c | 5 ++---
> fs/cifs/cifsproto.h | 4 ++--
> fs/cifs/connect.c | 1 +
> fs/cifs/dns_resolve.c | 20 +++++++++-----------
> fs/cifs/netmisc.c | 45 ++++++++++++++++++++++++---------------------
> 5 files changed, 38 insertions(+), 37 deletions(-)
>
> diff --git a/fs/cifs/cifs_dfs_ref.c b/fs/cifs/cifs_dfs_ref.c
> index ac19a6f..37543e8 100644
> --- a/fs/cifs/cifs_dfs_ref.c
> +++ b/fs/cifs/cifs_dfs_ref.c
> @@ -141,7 +141,7 @@ char *cifs_compose_mount_options(const char *sb_mountdata,
> }
>
> rc = dns_resolve_server_name_to_ip(*devname, &srvIP);
> - if (rc != 0) {
> + if (rc < 0) {
> cERROR(1, "%s: Failed to resolve server part of %s to IP: %d",
> __func__, *devname, rc);
> goto compose_mount_options_err;
> @@ -150,8 +150,7 @@ char *cifs_compose_mount_options(const char *sb_mountdata,
> * assuming that we have 'unc=' and 'ip=' in
> * the original sb_mountdata
> */
> - md_len = strlen(sb_mountdata) + strlen(srvIP) +
> - strlen(ref->node_name) + 12;
> + md_len = strlen(sb_mountdata) + rc + strlen(ref->node_name) + 12;
> mountdata = kzalloc(md_len+1, GFP_KERNEL);
> if (mountdata == NULL) {
> rc = -ENOMEM;
> diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
> index 2eaebbd..1f54508 100644
> --- a/fs/cifs/cifsproto.h
> +++ b/fs/cifs/cifsproto.h
> @@ -86,8 +86,8 @@ extern unsigned int smbCalcSize(struct smb_hdr *ptr);
> extern unsigned int smbCalcSize_LE(struct smb_hdr *ptr);
> extern int decode_negTokenInit(unsigned char *security_blob, int length,
> struct TCP_Server_Info *server);
> -extern int cifs_convert_address(struct sockaddr *dst, char *src);
> -extern int cifs_fill_sockaddr(struct sockaddr *dst, char *src,
> +extern int cifs_convert_address(struct sockaddr *dst, const char *src, int len);
> +extern int cifs_fill_sockaddr(struct sockaddr *dst, const char *src, int len,
> unsigned short int port);
> extern int map_smb_to_linux_error(struct smb_hdr *smb, int logErr);
> extern void header_assemble(struct smb_hdr *, char /* command */ ,
> diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
> index 399b601..7a78b49 100644
> --- a/fs/cifs/connect.c
> +++ b/fs/cifs/connect.c
> @@ -1538,6 +1538,7 @@ cifs_get_tcp_session(struct smb_vol *volume_info)
> if (volume_info->UNCip && volume_info->UNC) {
> rc = cifs_fill_sockaddr((struct sockaddr *)&addr,
> volume_info->UNCip,
> + strlen(volume_info->UNCip),
> volume_info->port);
> if (!rc) {
> /* we failed translating address */
> diff --git a/fs/cifs/dns_resolve.c b/fs/cifs/dns_resolve.c
> index ff6fa2f..8de3b98 100644
> --- a/fs/cifs/dns_resolve.c
> +++ b/fs/cifs/dns_resolve.c
> @@ -40,11 +40,11 @@ static const struct cred *dns_resolver_cache;
> * 0 - name is not IP
> */
> static int
> -is_ip(char *name)
> +is_ip(const char *name, int len)
> {
> struct sockaddr_storage ss;
>
> - return cifs_convert_address((struct sockaddr *)&ss, name);
> + return cifs_convert_address((struct sockaddr *)&ss, name, len);
> }
>
> static int
> @@ -54,6 +54,10 @@ dns_resolver_instantiate(struct key *key, const void *data,
> int rc = 0;
> char *ip;
>
> + /* make sure this looks like an address */
> + if (!is_ip(data, datalen))
> + return -EINVAL;
> +
> ip = kmalloc(datalen + 1, GFP_KERNEL);
> if (!ip)
> return -ENOMEM;
> @@ -61,12 +65,6 @@ dns_resolver_instantiate(struct key *key, const void *data,
> memcpy(ip, data, datalen);
> ip[datalen] = '\0';
>
> - /* make sure this looks like an address */
> - if (!is_ip(ip)) {
> - kfree(ip);
> - return -EINVAL;
> - }
> -
> key->type_data.x[0] = datalen;
> key->payload.data = ip;
>
> @@ -93,7 +91,7 @@ struct key_type key_type_dns_resolver = {
> * unc - server UNC
> * output:
> * *ip_addr - pointer to server ip, caller responcible for freeing it.
> - * return 0 on success
> + * return the length of the returned string on success
> */
> int
> dns_resolve_server_name_to_ip(const char *unc, char **ip_addr)
> @@ -131,7 +129,7 @@ dns_resolve_server_name_to_ip(const char *unc, char **ip_addr)
> memcpy(name, unc+2, len);
> name[len] = 0;
>
> - if (is_ip(name)) {
> + if (is_ip(name, len)) {
> cFYI(1, "%s: it is IP, skipping dns upcall: %s",
> __func__, name);
> data = name;
> @@ -164,7 +162,7 @@ skip_upcall:
> name,
> *ip_addr
> );
> - rc = 0;
> + rc = len;
> } else {
> rc = -ENOMEM;
> }
> diff --git a/fs/cifs/netmisc.c b/fs/cifs/netmisc.c
> index 3489468..b7f5975 100644
> --- a/fs/cifs/netmisc.c
> +++ b/fs/cifs/netmisc.c
> @@ -139,17 +139,18 @@ static const struct smb_to_posix_error mapping_table_ERRHRD[] = {
> * Returns 0 on failure.
> */
> static int
> -cifs_inet_pton(const int address_family, const char *cp, void *dst)
> +cifs_inet_pton(const int address_family, const char *cp, int len, void *dst)
> {
> int ret = 0;
>
> /* calculate length by finding first slash or NULL */
> if (address_family == AF_INET)
> - ret = in4_pton(cp, -1 /* len */, dst, '\\', NULL);
> + ret = in4_pton(cp, len, dst, '\\', NULL);
> else if (address_family == AF_INET6)
> - ret = in6_pton(cp, -1 /* len */, dst , '\\', NULL);
> + ret = in6_pton(cp, len, dst , '\\', NULL);
>
> - cFYI(DBG2, "address conversion returned %d for %s", ret, cp);
> + cFYI(DBG2, "address conversion returned %d for %*.*s",
> + ret, len, len, cp);
> if (ret > 0)
> ret = 1;
> return ret;
> @@ -164,37 +165,39 @@ cifs_inet_pton(const int address_family, const char *cp, void *dst)
> * Returns 0 on failure.
> */
> int
> -cifs_convert_address(struct sockaddr *dst, char *src)
> +cifs_convert_address(struct sockaddr *dst, const char *src, int len)
> {
> - int rc;
> - char *pct, *endp;
> + int rc, alen, slen;
> + const char *pct;
> + char *endp, scope_id[13];
> struct sockaddr_in *s4 = (struct sockaddr_in *) dst;
> struct sockaddr_in6 *s6 = (struct sockaddr_in6 *) dst;
>
> /* IPv4 address */
> - if (cifs_inet_pton(AF_INET, src, &s4->sin_addr.s_addr)) {
> + if (cifs_inet_pton(AF_INET, src, len, &s4->sin_addr.s_addr)) {
> s4->sin_family = AF_INET;
> return 1;
> }
>
> - /* temporarily terminate string */
> - pct = strchr(src, '%');
> - if (pct)
> - *pct = '\0';
> -
> - rc = cifs_inet_pton(AF_INET6, src, &s6->sin6_addr.s6_addr);
> -
> - /* repair temp termination (if any) and make pct point to scopeid */
> - if (pct)
> - *pct++ = '%';
> + /* attempt to exclude the scope ID from the address part */
> + pct = memchr(src, '%', len);
> + alen = pct ? pct - src : len;
>
> + rc = cifs_inet_pton(AF_INET6, src, alen, &s6->sin6_addr.s6_addr);
> if (!rc)
> return rc;
>
> s6->sin6_family = AF_INET6;
> if (pct) {
> + /* grab the scope ID */
> + slen = len - (alen + 1);
> + if (slen <= 0 || slen > 12)
> + return 0;
> + memcpy(scope_id, pct + 1, slen);
> + scope_id[slen] = '\0';
> +
> s6->sin6_scope_id = (u32) simple_strtoul(pct, &endp, 0);
> - if (!*pct || *endp)
> + if (endp != scope_id + slen)
> return 0;
> }
>
> @@ -202,10 +205,10 @@ cifs_convert_address(struct sockaddr *dst, char *src)
> }
>
> int
> -cifs_fill_sockaddr(struct sockaddr *dst, char *src,
> +cifs_fill_sockaddr(struct sockaddr *dst, const char *src, int len,
> const unsigned short int port)
> {
> - if (!cifs_convert_address(dst, src))
> + if (!cifs_convert_address(dst, src, len))
> return 0;
>
> switch (dst->sa_family) {
>

Looks good. I like the fact that we'll no longer be munging the source
string in cifs_convert_address.

Acked-by: Jeff Layton <jlayton(a)redhat.com>
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Prev: Fix false positive BUG_ON in __page_set_anon_rmap
Next: [PATCH 4/6] CIFS: Use d_automount() rather than abusing follow_link()