diff options
Diffstat (limited to 'fs/cifs/cifs_dfs_ref.c')
| -rw-r--r-- | fs/cifs/cifs_dfs_ref.c | 141 |
1 files changed, 72 insertions, 69 deletions
diff --git a/fs/cifs/cifs_dfs_ref.c b/fs/cifs/cifs_dfs_ref.c index 8e33ec65847b..58df174deb10 100644 --- a/fs/cifs/cifs_dfs_ref.c +++ b/fs/cifs/cifs_dfs_ref.c @@ -18,6 +18,7 @@ #include <linux/slab.h> #include <linux/vfs.h> #include <linux/fs.h> +#include <linux/inet.h> #include "cifsglob.h" #include "cifsproto.h" #include "cifsfs.h" @@ -48,58 +49,74 @@ void cifs_dfs_release_automount_timer(void) } /** - * cifs_get_share_name - extracts share name from UNC - * @node_name: pointer to UNC string + * cifs_build_devname - build a devicename from a UNC and optional prepath + * @nodename: pointer to UNC string + * @prepath: pointer to prefixpath (or NULL if there isn't one) * - * Extracts sharename form full UNC. - * i.e. strips from UNC trailing path that is not part of share - * name and fixup missing '\' in the beginning of DFS node refferal - * if necessary. - * Returns pointer to share name on success or ERR_PTR on error. - * Caller is responsible for freeing returned string. + * Build a new cifs devicename after chasing a DFS referral. Allocate a buffer + * big enough to hold the final thing. Copy the UNC from the nodename, and + * concatenate the prepath onto the end of it if there is one. + * + * Returns pointer to the built string, or a ERR_PTR. Caller is responsible + * for freeing the returned string. */ -static char *cifs_get_share_name(const char *node_name) +static char * +cifs_build_devname(char *nodename, const char *prepath) { - int len; - char *UNC; - char *pSep; - - len = strlen(node_name); - UNC = kmalloc(len+2 /*for term null and additional \ if it's missed */, - GFP_KERNEL); - if (!UNC) - return ERR_PTR(-ENOMEM); + size_t pplen; + size_t unclen; + char *dev; + char *pos; + + /* skip over any preceding delimiters */ + nodename += strspn(nodename, "\\"); + if (!*nodename) + return ERR_PTR(-EINVAL); - /* get share name and server name */ - if (node_name[1] != '\\') { - UNC[0] = '\\'; - strncpy(UNC+1, node_name, len); - len++; - UNC[len] = 0; - } else { - strncpy(UNC, node_name, len); - UNC[len] = 0; - } + /* get length of UNC and set pos to last char */ + unclen = strlen(nodename); + pos = nodename + unclen - 1; - /* find server name end */ - pSep = memchr(UNC+2, '\\', len-2); - if (!pSep) { - cifs_dbg(VFS, "%s: no server name end in node name: %s\n", - __func__, node_name); - kfree(UNC); - return ERR_PTR(-EINVAL); + /* trim off any trailing delimiters */ + while (*pos == '\\') { + --pos; + --unclen; } - /* find sharename end */ - pSep++; - pSep = memchr(UNC+(pSep-UNC), '\\', len-(pSep-UNC)); - if (pSep) { - /* trim path up to sharename end - * now we have share name in UNC */ - *pSep = 0; + /* allocate a buffer: + * +2 for preceding "//" + * +1 for delimiter between UNC and prepath + * +1 for trailing NULL + */ + pplen = prepath ? strlen(prepath) : 0; + dev = kmalloc(2 + unclen + 1 + pplen + 1, GFP_KERNEL); + if (!dev) + return ERR_PTR(-ENOMEM); + + pos = dev; + /* add the initial "//" */ + *pos = '/'; + ++pos; + *pos = '/'; + ++pos; + + /* copy in the UNC portion from referral */ + memcpy(pos, nodename, unclen); + pos += unclen; + + /* copy the prefixpath remainder (if there is one) */ + if (pplen) { + *pos = '/'; + ++pos; + memcpy(pos, prepath, pplen); + pos += pplen; } - return UNC; + /* NULL terminator */ + *pos = '\0'; + + convert_delimiter(dev, '/'); + return dev; } @@ -123,6 +140,7 @@ char *cifs_compose_mount_options(const char *sb_mountdata, { int rc; char *mountdata = NULL; + const char *prepath = NULL; int md_len; char *tkn_e; char *srvIP = NULL; @@ -132,7 +150,10 @@ char *cifs_compose_mount_options(const char *sb_mountdata, if (sb_mountdata == NULL) return ERR_PTR(-EINVAL); - *devname = cifs_get_share_name(ref->node_name); + if (strlen(fullpath) - ref->path_consumed) + prepath = fullpath + ref->path_consumed; + + *devname = cifs_build_devname(ref->node_name, prepath); if (IS_ERR(*devname)) { rc = PTR_ERR(*devname); *devname = NULL; @@ -146,12 +167,14 @@ char *cifs_compose_mount_options(const char *sb_mountdata, goto compose_mount_options_err; } - /* md_len = strlen(...) + 12 for 'sep+prefixpath=' - * assuming that we have 'unc=' and 'ip=' in - * the original sb_mountdata + /* + * In most cases, we'll be building a shorter string than the original, + * but we do have to assume that the address in the ip= option may be + * much longer than the original. Add the max length of an address + * string to the length of the original string to allow for worst case. */ - md_len = strlen(sb_mountdata) + rc + strlen(ref->node_name) + 12; - mountdata = kzalloc(md_len+1, GFP_KERNEL); + md_len = strlen(sb_mountdata) + INET6_ADDRSTRLEN; + mountdata = kzalloc(md_len + 1, GFP_KERNEL); if (mountdata == NULL) { rc = -ENOMEM; goto compose_mount_options_err; @@ -195,26 +218,6 @@ char *cifs_compose_mount_options(const char *sb_mountdata, strncat(mountdata, &sep, 1); strcat(mountdata, "ip="); strcat(mountdata, srvIP); - strncat(mountdata, &sep, 1); - strcat(mountdata, "unc="); - strcat(mountdata, *devname); - - /* find & copy prefixpath */ - tkn_e = strchr(ref->node_name + 2, '\\'); - if (tkn_e == NULL) { - /* invalid unc, missing share name*/ - rc = -EINVAL; - goto compose_mount_options_err; - } - - tkn_e = strchr(tkn_e + 1, '\\'); - if (tkn_e || (strlen(fullpath) - ref->path_consumed)) { - strncat(mountdata, &sep, 1); - strcat(mountdata, "prefixpath="); - if (tkn_e) - strcat(mountdata, tkn_e + 1); - strcat(mountdata, fullpath + ref->path_consumed); - } /*cifs_dbg(FYI, "%s: parent mountdata: %s\n", __func__, sb_mountdata);*/ /*cifs_dbg(FYI, "%s: submount mountdata: %s\n", __func__, mountdata );*/ |