lighttpd
/
lighttpd1.4
2
0
Fork 0
Code Issues Releases Wiki Activity

[mod_alias] modify r->physical.path in place 

(reduce string copying)

split out func mod_alias_remap() from handler func for unit testing
personal/stbuehler/tests-path
Glenn Strauss 2021-01-16 21:54:49 -05:00
parent 43cc87dd67
commit 62a874df32
1 changed files with 58 additions and 47 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

105
src/mod_alias.c
View File

@ -117,54 +117,65 @@ SETDEFAULTS_FUNC(mod_alias_set_defaults) {
return HANDLER_GO_ON;
}
static handler_t
mod_alias_remap (request_st * const r, const array * const aliases)
{
/* do not include trailing slash on basedir */
uint32_t basedir_len = buffer_string_length(&r->physical.basedir);
if ('/' == r->physical.basedir.ptr[basedir_len-1]) --basedir_len;
const uint32_t path_len = buffer_string_length(&r->physical.path);
if (0 == path_len || path_len < basedir_len) return HANDLER_GO_ON;
const uint32_t uri_len = path_len - basedir_len;
const char * const uri_ptr = r->physical.path.ptr + basedir_len;
data_string * const ds = (data_string *)
(!r->conf.force_lowercase_filenames
? array_match_key_prefix_klen(aliases, uri_ptr, uri_len)
: array_match_key_prefix_nc_klen(aliases, uri_ptr, uri_len));
if (NULL == ds) return HANDLER_GO_ON;
/* matched */
const uint32_t alias_len = buffer_string_length(&ds->key);
const uint32_t vlen = buffer_string_length(&ds->value);
/* check for path traversal in url-path following alias if key
* does not end in slash, but replacement value ends in slash */
if (uri_ptr[alias_len] == '.') {
const char *s = uri_ptr + alias_len + 1;
if (*s == '.') ++s;
if (*s == '/' || *s == '\0') {
if (0 != alias_len && ds->key.ptr[alias_len-1] != '/'
&& 0 != vlen && ds->value.ptr[vlen-1] == '/') {
r->http_status = 403;
return HANDLER_FINISHED;
}
}
}
/*(not buffer_append_path_len();
* alias could be prefix instead of complete path segment,
* (though resulting r->physical.basedir would not be a dir))*/
if (vlen != basedir_len + alias_len) {
const uint32_t nlen = vlen + uri_len - alias_len;
if (path_len + buffer_string_space(&r->physical.path) < nlen)
buffer_string_prepare_append(&r->physical.path, nlen - path_len);
memmove(r->physical.path.ptr + vlen,
uri_ptr + alias_len, uri_len - alias_len);
buffer_string_set_length(&r->physical.path, nlen);
}
memcpy(r->physical.path.ptr, ds->value.ptr, vlen);
buffer_copy_string_len(&r->physical.basedir, ds->value.ptr, vlen);
return HANDLER_GO_ON;
}
PHYSICALPATH_FUNC(mod_alias_physical_handler) {
plugin_data *p = p_d;
char *uri_ptr;
size_t uri_len = buffer_string_length(&r->physical.path);
size_t basedir_len, alias_len;
data_string *ds;
if (0 == uri_len) return HANDLER_GO_ON;
mod_alias_patch_config(r, p);
if (NULL == p->conf.alias) return HANDLER_GO_ON;
/* do not include trailing slash on basedir */
basedir_len = buffer_string_length(&r->physical.basedir);
if ('/' == r->physical.basedir.ptr[basedir_len-1]) --basedir_len;
uri_len -= basedir_len;
uri_ptr = r->physical.path.ptr + basedir_len;
ds = (!r->conf.force_lowercase_filenames)
? (data_string *)array_match_key_prefix_klen(p->conf.alias, uri_ptr, uri_len)
: (data_string *)array_match_key_prefix_nc_klen(p->conf.alias, uri_ptr, uri_len);
if (NULL == ds) { return HANDLER_GO_ON; }
/* matched */
/* check for path traversal in url-path following alias if key
* does not end in slash, but replacement value ends in slash */
alias_len = buffer_string_length(&ds->key);
if (uri_ptr[alias_len] == '.') {
char *s = uri_ptr + alias_len + 1;
if (*s == '.') ++s;
if (*s == '/' || *s == '\0') {
size_t vlen = buffer_string_length(&ds->value);
if (0 != alias_len && ds->key.ptr[alias_len-1] != '/'
&& 0 != vlen && ds->value.ptr[vlen-1] == '/') {
r->http_status = 403;
return HANDLER_FINISHED;
}
}
}
buffer * const tb = r->tmp_buf;
buffer_copy_buffer(&r->physical.basedir, &ds->value);
buffer_copy_buffer(tb, &ds->value);
buffer_append_string(tb, uri_ptr + alias_len);
buffer_copy_buffer(&r->physical.path, tb);
return HANDLER_GO_ON;
plugin_data * const p = p_d;
mod_alias_patch_config(r, p);
return p->conf.alias ? mod_alias_remap(r, p->conf.alias) : HANDLER_GO_ON;
}