s4-heimdal: Fix typos in comment.

[Samba.git] / source4 / ntvfs / posix / pvfs_resolve.c

/* 
   Unix SMB/CIFS implementation.

   POSIX NTVFS backend - filename resolution

   Copyright (C) Andrew Tridgell 2004

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

/*
  this is the core code for converting a filename from the format as
  given by a client to a posix filename, including any case-matching
  required, and checks for legal characters
*/


#include "includes.h"
#include "vfs_posix.h"
#include "system/dir.h"
#include "param/param.h"

/**
  compare two filename components. This is where the name mangling hook will go
*/
static int component_compare(struct pvfs_state *pvfs, const char *comp, const char *name)
{
        int ret;

        ret = strcasecmp_m(comp, name);

        if (ret != 0) {
                char *shortname = pvfs_short_name_component(pvfs, name);
                if (shortname) {
                        ret = strcasecmp_m(comp, shortname);
                        talloc_free(shortname);
                }
        }

        return ret;
}

/*
  search for a filename in a case insensitive fashion

  TODO: add a cache for previously resolved case-insensitive names
  TODO: add mangled name support
*/
static NTSTATUS pvfs_case_search(struct pvfs_state *pvfs,
                                 struct pvfs_filename *name,
                                 unsigned int flags)
{
        /* break into a series of components */
        int num_components;
        char **components;
        char *p, *partial_name;
        int i;

        /* break up the full name info pathname components */
        num_components=2;
        p = name->full_name + strlen(pvfs->base_directory) + 1;

        for (;*p;p++) {
                if (*p == '/') {
                        num_components++;
                }
        }

        components = talloc_array(name, char *, num_components);
        p = name->full_name + strlen(pvfs->base_directory);
        *p++ = 0;

        components[0] = name->full_name;

        for (i=1;i<num_components;i++) {
                components[i] = p;
                p = strchr(p, '/');
                if (p) *p++ = 0;
                if (pvfs_is_reserved_name(pvfs, components[i])) {
                        return NT_STATUS_ACCESS_DENIED;
                }
        }

        partial_name = talloc_strdup(name, components[0]);
        if (!partial_name) {
                return NT_STATUS_NO_MEMORY;
        }

        /* for each component, check if it exists as-is, and if not then
           do a directory scan */
        for (i=1;i<num_components;i++) {
                char *test_name;
                DIR *dir;
                struct dirent *de;
                char *long_component;

                /* possibly remap from the short name cache */
                long_component = pvfs_mangled_lookup(pvfs, name, components[i]);
                if (long_component) {
                        components[i] = long_component;
                }

                test_name = talloc_asprintf(name, "%s/%s", partial_name, components[i]);
                if (!test_name) {
                        return NT_STATUS_NO_MEMORY;
                }

                /* check if this component exists as-is */
                if (stat(test_name, &name->st) == 0) {
                        if (i<num_components-1 && !S_ISDIR(name->st.st_mode)) {
                                return NT_STATUS_OBJECT_PATH_NOT_FOUND;
                        }
                        talloc_free(partial_name);
                        partial_name = test_name;
                        if (i == num_components - 1) {
                                name->exists = true;
                        }
                        continue;
                }

                /* the filesystem might be case insensitive, in which
                   case a search is pointless unless the name is
                   mangled */
                if ((pvfs->flags & PVFS_FLAG_CI_FILESYSTEM) &&
                    !pvfs_is_mangled_component(pvfs, components[i])) {
                        if (i < num_components-1) {
                                return NT_STATUS_OBJECT_PATH_NOT_FOUND;
                        }
                        partial_name = test_name;
                        continue;
                }
                
                dir = opendir(partial_name);
                if (!dir) {
                        return pvfs_map_errno(pvfs, errno);
                }

                while ((de = readdir(dir))) {
                        if (component_compare(pvfs, components[i], de->d_name) == 0) {
                                break;
                        }
                }

                if (!de) {
                        if (i < num_components-1) {
                                closedir(dir);
                                return NT_STATUS_OBJECT_PATH_NOT_FOUND;
                        }
                } else {
                        components[i] = talloc_strdup(name, de->d_name);
                }
                test_name = talloc_asprintf(name, "%s/%s", partial_name, components[i]);
                talloc_free(partial_name);
                partial_name = test_name;

                closedir(dir);
        }

        if (!name->exists) {
                if (stat(partial_name, &name->st) == 0) {
                        name->exists = true;
                }
        }

        talloc_free(name->full_name);
        name->full_name = partial_name;

        if (name->exists) {
                return pvfs_fill_dos_info(pvfs, name, flags, -1);
        }

        return NT_STATUS_OK;
}

/*
  parse a alternate data stream name
*/
static NTSTATUS parse_stream_name(struct smb_iconv_convenience *ic,
                                  struct pvfs_filename *name,
                                  const char *s)
{
        char *p, *stream_name;
        if (s[1] == '\0') {
                return NT_STATUS_OBJECT_NAME_INVALID;
        }
        name->stream_name = stream_name = talloc_strdup(name, s+1);
        if (name->stream_name == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        p = stream_name;

        while (*p) {
                size_t c_size;
                codepoint_t c = next_codepoint_convenience(ic, p, &c_size);

                switch (c) {
                case '/':
                case '\\':
                        return NT_STATUS_OBJECT_NAME_INVALID;
                case ':':
                        *p= 0;
                        p++;
                        if (*p == '\0') {
                                return NT_STATUS_OBJECT_NAME_INVALID;
                        }
                        if (strcasecmp_m(p, "$DATA") != 0) {
                                if (strchr_m(p, ':')) {
                                        return NT_STATUS_OBJECT_NAME_INVALID;
                                }
                                return NT_STATUS_INVALID_PARAMETER;
                        }
                        c_size = 0;
                        p--;
                        break;
                }

                p += c_size;
        }

        if (strcmp(name->stream_name, "") == 0) {
                /*
                 * we don't set stream_name to NULL, here
                 * as this would be wrong for directories
                 *
                 * pvfs_fill_dos_info() will set it to NULL
                 * if it's not a directory.
                 */
                name->stream_id = 0;
        } else {
                name->stream_id = pvfs_name_hash(name->stream_name, 
                                                 strlen(name->stream_name));
        }
                                                 
        return NT_STATUS_OK;    
}


/*
  convert a CIFS pathname to a unix pathname. Note that this does NOT
  take into account case insensitivity, and in fact does not access
  the filesystem at all. It is merely a reformatting and charset
  checking routine.

  errors are returned if the filename is illegal given the flags
*/
static NTSTATUS pvfs_unix_path(struct pvfs_state *pvfs, const char *cifs_name,
                               unsigned int flags, struct pvfs_filename *name)
{
        char *ret, *p, *p_start;
        struct smb_iconv_convenience *ic = NULL;
        NTSTATUS status;

        name->original_name = talloc_strdup(name, cifs_name);

        /* remove any :$DATA */
        p = strrchr(name->original_name, ':');
        if (p && strcasecmp_m(p, ":$DATA") == 0) {
                if (p > name->original_name && p[-1] == ':') {
                        p--;
                }
                *p = 0;
        }

        name->stream_name = NULL;
        name->stream_id = 0;
        name->has_wildcard = false;

        while (*cifs_name == '\\') {
                cifs_name++;
        }

        if (*cifs_name == 0) {
                name->full_name = talloc_asprintf(name, "%s/.", pvfs->base_directory);
                if (name->full_name == NULL) {
                        return NT_STATUS_NO_MEMORY;
                }
                return NT_STATUS_OK;
        }

        ret = talloc_asprintf(name, "%s/%s", pvfs->base_directory, cifs_name);
        if (ret == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        p = ret + strlen(pvfs->base_directory) + 1;

        /* now do an in-place conversion of '\' to '/', checking
           for legal characters */
        p_start = p;

        ic = lp_iconv_convenience(pvfs->ntvfs->ctx->lp_ctx);
        while (*p) {
                size_t c_size;
                codepoint_t c = next_codepoint_convenience(ic, p, &c_size);

                if (c <= 0x1F) {
                        return NT_STATUS_OBJECT_NAME_INVALID;
                }

                switch (c) {
                case '\\':
                        if (name->has_wildcard) {
                                /* wildcards are only allowed in the last part
                                   of a name */
                                return NT_STATUS_OBJECT_NAME_INVALID;
                        }
                        if (p > p_start && (p[1] == '\\' || p[1] == '\0')) {
                                /* see if it is definately a "\\" or
                                 * a trailing "\". If it is then fail here,
                                 * and let the next layer up try again after
                                 * pvfs_reduce_name() if it wants to. This is
                                 * much more efficient on average than always
                                 * scanning for these separately
                                 */
                                return NT_STATUS_OBJECT_PATH_SYNTAX_BAD;
                        } else {
                                *p = '/';
                        }
                        break;
                case ':':
                        if (!(flags & PVFS_RESOLVE_STREAMS)) {
                                return NT_STATUS_OBJECT_NAME_INVALID;
                        }
                        if (name->has_wildcard) {
                                return NT_STATUS_OBJECT_NAME_INVALID;
                        }
                        status = parse_stream_name(ic, name, p);
                        if (!NT_STATUS_IS_OK(status)) {
                                return status;
                        }
                        *p-- = 0;
                        break;
                case '*':
                case '>':
                case '<':
                case '?':
                case '"':
                        if (!(flags & PVFS_RESOLVE_WILDCARD)) {
                                return NT_STATUS_OBJECT_NAME_INVALID;
                        }
                        name->has_wildcard = true;
                        break;
                case '/':
                case '|':
                        return NT_STATUS_OBJECT_NAME_INVALID;
                case '.':
                        /* see if it is definately a .. or
                           . component. If it is then fail here, and
                           let the next layer up try again after
                           pvfs_reduce_name() if it wants to. This is
                           much more efficient on average than always
                           scanning for these separately */
                        if (p[1] == '.' && 
                            (p[2] == 0 || p[2] == '\\') &&
                            (p == p_start || p[-1] == '/')) {
                                return NT_STATUS_OBJECT_PATH_SYNTAX_BAD;
                        }
                        if ((p[1] == 0 || p[1] == '\\') &&
                            (p == p_start || p[-1] == '/')) {
                                return NT_STATUS_OBJECT_PATH_SYNTAX_BAD;
                        }
                        break;
                }

                p += c_size;
        }

        name->full_name = ret;

        return NT_STATUS_OK;
}


/*
  reduce a name that contains .. components or repeated \ separators
  return NULL if it can't be reduced
*/
static NTSTATUS pvfs_reduce_name(TALLOC_CTX *mem_ctx, 
                                 struct smb_iconv_convenience *iconv_convenience, 
                                 const char **fname, unsigned int flags)
{
        codepoint_t c;
        size_t c_size, len;
        int i, num_components, err_count;
        char **components;
        char *p, *s, *ret;

        s = talloc_strdup(mem_ctx, *fname);
        if (s == NULL) return NT_STATUS_NO_MEMORY;

        for (num_components=1, p=s; *p; p += c_size) {
                c = next_codepoint_convenience(iconv_convenience, p, &c_size);
                if (c == '\\') num_components++;
        }

        components = talloc_array(s, char *, num_components+1);
        if (components == NULL) {
                talloc_free(s);
                return NT_STATUS_NO_MEMORY;
        }

        components[0] = s;
        for (i=0, p=s; *p; p += c_size) {
                c = next_codepoint_convenience(iconv_convenience, p, &c_size);
                if (c == '\\') {
                        *p = 0;
                        components[++i] = p+1;
                }
        }
        components[i+1] = NULL;

        /*
          rather bizarre!

          '.' components are not allowed, but the rules for what error
          code to give don't seem to make sense. This is a close
          approximation.
        */
        for (err_count=i=0;components[i];i++) {
                if (strcmp(components[i], "") == 0) {
                        continue;
                }
                if (ISDOT(components[i]) || err_count) {
                        err_count++;
                }
        }
        if (err_count) {
                if (flags & PVFS_RESOLVE_WILDCARD) err_count--;

                if (err_count==1) {
                        return NT_STATUS_OBJECT_NAME_INVALID;
                } else {
                        return NT_STATUS_OBJECT_PATH_NOT_FOUND;
                }
        }

        /* remove any null components */
        for (i=0;components[i];i++) {
                if (strcmp(components[i], "") == 0) {
                        memmove(&components[i], &components[i+1], 
                                sizeof(char *)*(num_components-i));
                        i--;
                        continue;
                }
                if (ISDOTDOT(components[i])) {
                        if (i < 1) return NT_STATUS_OBJECT_PATH_SYNTAX_BAD;
                        memmove(&components[i-1], &components[i+1], 
                                sizeof(char *)*(num_components-i));
                        i -= 2;
                        continue;
                }
        }

        if (components[0] == NULL) {
                talloc_free(s);
                *fname = talloc_strdup(mem_ctx, "\\");
                return NT_STATUS_OK;
        }

        for (len=i=0;components[i];i++) {
                len += strlen(components[i]) + 1;
        }

        /* rebuild the name */
        ret = talloc_array(mem_ctx, char, len+1);
        if (ret == NULL) {
                talloc_free(s);
                return NT_STATUS_NO_MEMORY;
        }

        for (len=0,i=0;components[i];i++) {
                size_t len1 = strlen(components[i]);
                ret[len] = '\\';
                memcpy(ret+len+1, components[i], len1);
                len += len1 + 1;
        }       
        ret[len] = 0;

        talloc_set_name_const(ret, ret);

        talloc_free(s);

        *fname = ret;
        
        return NT_STATUS_OK;
}


/*
  resolve a name from relative client format to a struct pvfs_filename
  the memory for the filename is made as a talloc child of 'name'

  flags include:
     PVFS_RESOLVE_NO_WILDCARD = wildcards are considered illegal characters
     PVFS_RESOLVE_STREAMS     = stream names are allowed

     TODO: ../ collapsing, and outside share checking
*/
NTSTATUS pvfs_resolve_name(struct pvfs_state *pvfs, 
                           struct ntvfs_request *req,
                           const char *cifs_name,
                           unsigned int flags, struct pvfs_filename **name)
{
        NTSTATUS status;

        *name = talloc(req, struct pvfs_filename);
        if (*name == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        (*name)->exists = false;
        (*name)->stream_exists = false;

        if (!(pvfs->fs_attribs & FS_ATTR_NAMED_STREAMS)) {
                flags &= ~PVFS_RESOLVE_STREAMS;
        }

        /* SMB2 doesn't allow a leading slash */
        if (req->ctx->protocol == PROTOCOL_SMB2 &&
            *cifs_name == '\\') {
                return NT_STATUS_INVALID_PARAMETER;
        }

        /* do the basic conversion to a unix formatted path,
           also checking for allowable characters */
        status = pvfs_unix_path(pvfs, cifs_name, flags, *name);

        if (NT_STATUS_EQUAL(status, NT_STATUS_OBJECT_PATH_SYNTAX_BAD)) {
                /* it might contain .. components which need to be reduced */
                status = pvfs_reduce_name(*name, lp_iconv_convenience(pvfs->ntvfs->ctx->lp_ctx), &cifs_name, flags);
                if (!NT_STATUS_IS_OK(status)) {
                        return status;
                }
                status = pvfs_unix_path(pvfs, cifs_name, flags, *name);
        }

        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }

        /* if it has a wildcard then no point doing a stat() of the
           full name. Instead We need check if the directory exists 
         */
        if ((*name)->has_wildcard) {
                const char *p;
                char *dir_name, *saved_name;
                p = strrchr((*name)->full_name, '/');
                if (p == NULL) {
                        /* root directory wildcard is OK */
                        return NT_STATUS_OK;
                }
                dir_name = talloc_strndup(*name, (*name)->full_name, (p-(*name)->full_name));
                if (stat(dir_name, &(*name)->st) == 0) {
                        talloc_free(dir_name);
                        return NT_STATUS_OK;
                }
                /* we need to search for a matching name */
                saved_name = (*name)->full_name;
                (*name)->full_name = dir_name;
                status = pvfs_case_search(pvfs, *name, flags);
                if (!NT_STATUS_IS_OK(status)) {
                        /* the directory doesn't exist */
                        (*name)->full_name = saved_name;
                        return status;
                }
                /* it does exist, but might need a case change */
                if (dir_name != (*name)->full_name) {
                        (*name)->full_name = talloc_asprintf(*name, "%s%s",
                                                             (*name)->full_name, p);
                        NT_STATUS_HAVE_NO_MEMORY((*name)->full_name);
                } else {
                        (*name)->full_name = saved_name;
                        talloc_free(dir_name);
                }
                return NT_STATUS_OK;
        }

        /* if we can stat() the full name now then we are done */
        if (stat((*name)->full_name, &(*name)->st) == 0) {
                (*name)->exists = true;
                return pvfs_fill_dos_info(pvfs, *name, flags, -1);
        }

        /* search for a matching filename */
        status = pvfs_case_search(pvfs, *name, flags);

        return status;
}


/*
  do a partial resolve, returning a pvfs_filename structure given a
  base path and a relative component. It is an error if the file does
  not exist. No case-insensitive matching is done.

  this is used in places like directory searching where we need a pvfs_filename
  to pass to a function, but already know the unix base directory and component
*/
NTSTATUS pvfs_resolve_partial(struct pvfs_state *pvfs, TALLOC_CTX *mem_ctx,
                              const char *unix_dir, const char *fname,
                              unsigned int flags, struct pvfs_filename **name)
{
        NTSTATUS status;

        *name = talloc(mem_ctx, struct pvfs_filename);
        if (*name == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        (*name)->full_name = talloc_asprintf(*name, "%s/%s", unix_dir, fname);
        if ((*name)->full_name == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        if (stat((*name)->full_name, &(*name)->st) == -1) {
                return NT_STATUS_OBJECT_NAME_NOT_FOUND;
        }

        (*name)->exists = true;
        (*name)->stream_exists = true;
        (*name)->has_wildcard = false;
        (*name)->original_name = talloc_strdup(*name, fname);
        (*name)->stream_name = NULL;
        (*name)->stream_id = 0;

        status = pvfs_fill_dos_info(pvfs, *name, flags, -1);

        return status;
}


/*
  fill in the pvfs_filename info for an open file, given the current
  info for a (possibly) non-open file. This is used by places that need
  to update the pvfs_filename stat information, and by pvfs_open()
*/
NTSTATUS pvfs_resolve_name_fd(struct pvfs_state *pvfs, int fd,
                              struct pvfs_filename *name, unsigned int flags)
{
        dev_t device = (dev_t)0;
        ino_t inode = 0;

        if (name->exists) {
                device = name->st.st_dev;
                inode = name->st.st_ino;
        }

        if (fd == -1) {
                if (stat(name->full_name, &name->st) == -1) {
                        return NT_STATUS_INVALID_HANDLE;
                }
        } else {
                if (fstat(fd, &name->st) == -1) {
                        return NT_STATUS_INVALID_HANDLE;
                }
        }

        if (name->exists &&
            (device != name->st.st_dev || inode != name->st.st_ino)) {
                /* the file we are looking at has changed! this could
                 be someone trying to exploit a race
                 condition. Certainly we don't want to continue
                 operating on this file */
                DEBUG(0,("pvfs: WARNING: file '%s' changed during resolve - failing\n",
                         name->full_name));
                return NT_STATUS_UNEXPECTED_IO_ERROR;
        }

        name->exists = true;
        
        return pvfs_fill_dos_info(pvfs, name, flags, fd);
}

/*
  fill in the pvfs_filename info for an open file, given the current
  info for a (possibly) non-open file. This is used by places that need
  to update the pvfs_filename stat information, and the path
  after a possible rename on a different handle.
*/
NTSTATUS pvfs_resolve_name_handle(struct pvfs_state *pvfs,
                                  struct pvfs_file_handle *h)
{
        NTSTATUS status;

        if (h->have_opendb_entry) {
                struct odb_lock *lck;
                char *name = NULL;

                lck = odb_lock(h, h->pvfs->odb_context, &h->odb_locking_key);
                if (lck == NULL) {
                        DEBUG(0,("%s: failed to lock file '%s' in opendb\n",
                                 __FUNCTION__, h->name->full_name));
                        /* we were supposed to do a blocking lock, so something
                           is badly wrong! */
                        return NT_STATUS_INTERNAL_DB_CORRUPTION;
                }

                status = odb_get_path(lck, (const char **) &name);
                if (NT_STATUS_IS_OK(status)) {
                        /*
                         * This relies an the fact that
                         * renames of open files are only
                         * allowed by setpathinfo() and setfileinfo()
                         * and there're only renames within the same
                         * directory supported
                         */
                        if (strcmp(h->name->full_name, name) != 0) {
                                const char *orig_dir;
                                const char *new_file;
                                char *new_orig;
                                char *delim;

                                delim = strrchr(name, '/');
                                if (!delim) {
                                        talloc_free(lck);
                                        return NT_STATUS_INTERNAL_ERROR;
                                }

                                new_file = delim + 1;
                                delim = strrchr(h->name->original_name, '\\');
                                if (delim) {
                                        delim[0] = '\0';
                                        orig_dir = h->name->original_name;
                                        new_orig = talloc_asprintf(h->name, "%s\\%s",
                                                                   orig_dir, new_file);
                                        if (!new_orig) {
                                                talloc_free(lck);
                                                return NT_STATUS_NO_MEMORY;
                                        }
                                } else {
                                        new_orig = talloc_strdup(h->name, new_file);
                                        if (!new_orig) {
                                                talloc_free(lck);
                                                return NT_STATUS_NO_MEMORY;
                                        }
                                }

                                talloc_free(h->name->original_name);
                                talloc_free(h->name->full_name);
                                h->name->full_name = talloc_steal(h->name, name);
                                h->name->original_name = new_orig;
                        }
                }

                talloc_free(lck);
        }

        /*
         * TODO: pass PVFS_RESOLVE_NO_OPENDB and get
         *       the write time from odb_lock() above.
         */
        status = pvfs_resolve_name_fd(pvfs, h->fd, h->name, 0);
        NT_STATUS_NOT_OK_RETURN(status);

        if (!null_nttime(h->write_time.close_time)) {
                h->name->dos.write_time = h->write_time.close_time;
        }

        return NT_STATUS_OK;
}


/*
  resolve the parent of a given name
*/
NTSTATUS pvfs_resolve_parent(struct pvfs_state *pvfs, TALLOC_CTX *mem_ctx,
                             const struct pvfs_filename *child,
                             struct pvfs_filename **name)
{
        NTSTATUS status;
        char *p;

        *name = talloc(mem_ctx, struct pvfs_filename);
        if (*name == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        (*name)->full_name = talloc_strdup(*name, child->full_name);
        if ((*name)->full_name == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        p = strrchr_m((*name)->full_name, '/');
        if (p == NULL) {
                return NT_STATUS_OBJECT_PATH_SYNTAX_BAD;
        }

        /* this handles the root directory */
        if (p == (*name)->full_name) {
                p[1] = 0;
        } else {
                p[0] = 0;
        }

        if (stat((*name)->full_name, &(*name)->st) == -1) {
                return NT_STATUS_OBJECT_NAME_NOT_FOUND;
        }

        (*name)->exists = true;
        (*name)->stream_exists = true;
        (*name)->has_wildcard = false;
        /* we can't get the correct 'original_name', but for the purposes
           of this call this is close enough */
        (*name)->original_name = talloc_strdup(*name, child->original_name);
        if ((*name)->original_name == NULL) {
                return NT_STATUS_NO_MEMORY;
        }
        (*name)->stream_name = NULL;
        (*name)->stream_id = 0;

        status = pvfs_fill_dos_info(pvfs, *name, PVFS_RESOLVE_NO_OPENDB, -1);

        return status;
}