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libhttp/src/httplib_handle_form_request.c
Lammert Bies a03f2e301f Added debug levels to warnings
2016-12-29 03:10:24 +01:00

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/*
* Copyright (c) 2016 Lammert Bies
* Copyright (c) 2016 the Civetweb developers
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*
* ============
* Release: 2.0
*/
#include "httplib_main.h"
static int url_encoded_field_found(const struct httplib_connection *conn,
const char *key,
size_t key_len,
const char *filename,
size_t filename_len,
char *path,
size_t path_len,
struct httplib_form_data_handler *fdh) {
char key_dec[1024];
char filename_dec[1024];
int key_dec_len;
int filename_dec_len;
int ret;
key_dec_len = httplib_url_decode(key, (int)key_len, key_dec, (int)sizeof(key_dec), 1);
if (((size_t)key_dec_len >= (size_t)sizeof(key_dec)) || (key_dec_len < 0)) return FORM_FIELD_STORAGE_SKIP;
if ( filename != NULL ) {
filename_dec_len = httplib_url_decode( filename, (int)filename_len, filename_dec, (int)sizeof(filename_dec), 1 );
if (((size_t)filename_dec_len >= (size_t)sizeof(filename_dec)) || (filename_dec_len < 0)) {
/*
* Log error message and skip this field.
*/
httplib_cry( DEBUG_LEVEL_WARNING, conn->ctx, conn, "%s: Cannot decode filename", __func__ );
return FORM_FIELD_STORAGE_SKIP;
}
} else filename_dec[0] = 0;
ret = fdh->field_found( key_dec, filename_dec, path, path_len, fdh->user_data );
if ( (ret & 0xF) == FORM_FIELD_STORAGE_GET ) {
if ( fdh->field_get == NULL ) {
httplib_cry( DEBUG_LEVEL_WARNING, conn->ctx, conn, "%s: Function \"Get\" not available", __func__ );
return FORM_FIELD_STORAGE_SKIP;
}
}
if ( (ret & 0xF) == FORM_FIELD_STORAGE_STORE ) {
if ( fdh->field_store == NULL ) {
httplib_cry( DEBUG_LEVEL_WARNING, conn->ctx, conn, "%s: Function \"Store\" not available", __func__ );
return FORM_FIELD_STORAGE_SKIP;
}
}
return ret;
}
static int url_encoded_field_get(const struct httplib_connection *conn,
const char *key,
size_t key_len,
const char *value,
size_t value_len,
struct httplib_form_data_handler *fdh) {
char key_dec[1024];
char *value_dec = httplib_malloc( value_len+1 );
int value_dec_len;
int ret;
if ( value_dec == NULL ) {
/*
* Log error message and stop parsing the form data.
*/
httplib_cry( DEBUG_LEVEL_ERROR, conn->ctx, conn, "%s: Not enough memory (required: %lu)", __func__, (unsigned long)(value_len + 1));
return FORM_FIELD_STORAGE_ABORT;
}
httplib_url_decode( key, (int)key_len, key_dec, (int)sizeof(key_dec), 1 );
value_dec_len = httplib_url_decode( value, (int)value_len, value_dec, (int)value_len + 1, 1 );
ret = fdh->field_get( key_dec, value_dec, (size_t)value_dec_len, fdh->user_data );
value_dec = httplib_free( value_dec );
return ret;
} /* url_encoded_field_get */
static int unencoded_field_get(const struct httplib_connection *conn,
const char *key,
size_t key_len,
const char *value,
size_t value_len,
struct httplib_form_data_handler *fdh) {
char key_dec[1024];
UNUSED_PARAMETER(conn);
httplib_url_decode( key, (int)key_len, key_dec, (int)sizeof(key_dec), 1 );
return fdh->field_get( key_dec, value, value_len, fdh->user_data );
} /* unencoded_field_get */
static int field_stored( const struct httplib_connection *conn, const char *path, int64_t file_size, struct httplib_form_data_handler *fdh ) {
/*
* Equivalent to "upload" callback of "httplib_upload".
*/
UNUSED_PARAMETER(conn); /* we do not need httplib_cry here, so conn is currently unused */
return fdh->field_store( path, file_size, fdh->user_data );
}
static const char * search_boundary(const char *buf, size_t buf_len, const char *boundary, size_t boundary_len) {
/*
* We must do a binary search here, not a string search, since the buffer
* may contain '\x00' bytes, if binary data is transferred.
*/
int clen = (int)buf_len - (int)boundary_len - 4;
int i;
for (i = 0; i <= clen; i++) {
if (!memcmp(buf + i, "\r\n--", 4)) {
if (!memcmp(buf + i + 4, boundary, boundary_len)) return buf+i;
}
}
return NULL;
}
int httplib_handle_form_request(struct httplib_connection *conn, struct httplib_form_data_handler *fdh) {
const char *content_type;
char path[512];
char buf[1024];
int field_storage;
int buf_fill = 0;
int r;
int field_count = 0;
struct file fstore = STRUCT_FILE_INITIALIZER;
int64_t file_size = 0; /* init here, to a avoid a false positive
"uninitialized variable used" warning */
int has_body_data = (conn->request_info.content_length > 0) || (conn->is_chunked);
/*
* There are three ways to encode data from a HTML form:
* 1) method: GET (default)
* The form data is in the HTTP query string.
* 2) method: POST, enctype: "application/x-www-form-urlencoded"
* The form data is in the request body.
* The body is url encoded (the default encoding for POST).
* 3) method: POST, enctype: "multipart/form-data".
* The form data is in the request body of a multipart message.
* This is the typical way to handle file upload from a form.
*/
if ( ! has_body_data ) {
const char *data;
if ( strcmp( conn->request_info.request_method, "GET" ) ) {
/*
* No body data, but not a GET request.
* This is not a valid form request.
*/
return -1;
}
/*
* GET request: form data is in the query string.
* The entire data has already been loaded, so there is no nead to
* call httplib_read. We just need to split the query string into key-value
* pairs.
*/
data = conn->request_info.query_string;
if ( data == NULL ) return -1; /* No query string. */
/*
* Split data in a=1&b=xy&c=3&c=4 ...
*/
while ( *data ) {
const char *val = strchr(data, '=');
const char *next;
ptrdiff_t keylen, vallen;
if ( val == NULL ) break;
keylen = val - data;
/*
* In every "field_found" callback we ask what to do with the
* data ("field_storage"). This could be:
* FORM_FIELD_STORAGE_SKIP (0) ... ignore the value of this field
* FORM_FIELD_STORAGE_GET (1) ... read the data and call the get
* callback function
* FORM_FIELD_STORAGE_STORE (2) ... store the data in a file
* FORM_FIELD_STORAGE_READ (3) ... let the user read the data
* (for parsing long data on the fly)
* (currently not implemented)
* FORM_FIELD_STORAGE_ABORT (flag) ... stop parsing
*/
memset( path, 0, sizeof(path) );
field_count++;
field_storage = url_encoded_field_found( conn, data, (size_t)keylen, NULL, 0, path, sizeof(path) - 1, fdh );
val++;
next = strchr( val, '&' );
if ( next != NULL ) {
vallen = next - val;
next++;
}
else {
vallen = (ptrdiff_t)strlen(val);
next = val + vallen;
}
if ( field_storage == FORM_FIELD_STORAGE_GET ) {
/*
* Call callback
*/
url_encoded_field_get( conn, data, (size_t)keylen, val, (size_t)vallen, fdh );
}
if ( field_storage == FORM_FIELD_STORAGE_STORE ) {
/*
* Store the content to a file
*/
if ( XX_httplib_fopen( conn, path, "wb", &fstore ) == 0 ) fstore.fp = NULL;
file_size = 0;
if ( fstore.fp != NULL ) {
size_t n = (size_t)fwrite(val, 1, (size_t)vallen, fstore.fp);
if ((n != (size_t)vallen) || (ferror(fstore.fp))) {
httplib_cry( DEBUG_LEVEL_ERROR, conn->ctx, conn, "%s: Cannot write file %s", __func__, path );
fclose( fstore.fp );
fstore.fp = NULL;
XX_httplib_remove_bad_file( conn, path );
}
file_size += (int64_t)n;
if ( fstore.fp ) {
r = fclose( fstore.fp );
if (r == 0) {
/*
* stored successfully
*/
field_stored( conn, path, file_size, fdh );
}
else {
httplib_cry( DEBUG_LEVEL_ERROR, conn->ctx, conn, "%s: Error saving file %s", __func__, path );
XX_httplib_remove_bad_file( conn, path );
}
fstore.fp = NULL;
}
} else httplib_cry( DEBUG_LEVEL_ERROR, conn->ctx, conn, "%s: Cannot create file %s", __func__, path );
}
/*
* if (field_storage == FORM_FIELD_STORAGE_READ) {
* The idea of "field_storage=read" is to let the API user read
* data chunk by chunk and to some data processing on the fly.
* This should avoid the need to store data in the server:
* It should neither be stored in memory, like
* "field_storage=get" does, nor in a file like
* "field_storage=store".
* However, for a "GET" request this does not make any much
* sense, since the data is already stored in memory, as it is
* part of the query string.
*
* } */
if ((field_storage & FORM_FIELD_STORAGE_ABORT) == FORM_FIELD_STORAGE_ABORT) break; /* Stop parsing the request */
/*
* Proceed to next entry
*/
data = next;
}
return field_count;
}
content_type = httplib_get_header( conn, "Content-Type" );
if ( content_type == NULL
|| ! httplib_strcasecmp(content_type, "APPLICATION/X-WWW-FORM-URLENCODED")
|| ! httplib_strcasecmp(content_type, "APPLICATION/WWW-FORM-URLENCODED")) {
/*
* The form data is in the request body data, encoded in key/value
* pairs.
*/
int all_data_read = 0;
/*
* Read body data and split it in keys and values.
* The encoding is like in the "GET" case above: a=1&b&c=3&c=4.
* Here we use "POST", and read the data from the request body.
* The data read on the fly, so it is not required to buffer the
* entire request in memory before processing it.
*/
for (;;) {
const char *val;
const char *next;
ptrdiff_t keylen, vallen;
ptrdiff_t used;
int end_of_key_value_pair_found = 0;
int get_block;
if ((size_t)buf_fill < (sizeof(buf) - 1)) {
size_t to_read = sizeof(buf) - 1 - (size_t)buf_fill;
r = httplib_read( conn, buf + (size_t)buf_fill, to_read );
if ( r < 0 ) return -1; /* read error */
if ( r != (int)to_read ) {
/*
* TODO: Create a function to get "all_data_read" from
* the conn object. All data is read if the Content-Length
* has been reached, or if chunked encoding is used and
* the end marker has been read, or if the connection has
* been closed.
*/
all_data_read = 1;
}
buf_fill += r;
buf[buf_fill] = 0;
if ( buf_fill < 1 ) break;
}
val = strchr(buf, '=');
if ( val == NULL ) break;
keylen = val - buf;
val++;
/*
* Call callback
*/
memset( path, 0, sizeof(path) );
field_count++;
field_storage = url_encoded_field_found( conn, buf, (size_t)keylen, NULL, 0, path, sizeof(path) - 1, fdh );
if ( (field_storage & FORM_FIELD_STORAGE_ABORT) == FORM_FIELD_STORAGE_ABORT ) break; /* Stop parsing the request */
if ( field_storage == FORM_FIELD_STORAGE_STORE ) {
if (XX_httplib_fopen(conn, path, "wb", &fstore) == 0) fstore.fp = NULL;
file_size = 0;
if (!fstore.fp) httplib_cry( DEBUG_LEVEL_ERROR, conn->ctx, conn, "%s: Cannot create file %s", __func__, path);
}
get_block = 0;
/*
* Loop to read values larger than sizeof(buf)-keylen-2
*/
do {
next = strchr(val, '&');
if (next != NULL ) {
vallen = next - val;
next++;
end_of_key_value_pair_found = 1;
}
else {
vallen = (ptrdiff_t)strlen(val);
next = val + vallen;
}
if ( field_storage == FORM_FIELD_STORAGE_GET ) {
#if 0
if (!end_of_key_value_pair_found && !all_data_read) {
/* This callback will deliver partial contents */
}
#else
(void)all_data_read; /* avoid warning */
#endif
/* Call callback */
url_encoded_field_get(conn,
((get_block > 0) ? NULL : buf),
((get_block > 0) ? 0 : (size_t)keylen),
val,
(size_t)vallen,
fdh);
get_block++;
}
if ( fstore.fp ) {
size_t n = (size_t)fwrite(val, 1, (size_t)vallen, fstore.fp);
if ((n != (size_t)vallen) || (ferror(fstore.fp))) {
httplib_cry( DEBUG_LEVEL_ERROR, conn->ctx, conn, "%s: Cannot write file %s", __func__, path);
fclose(fstore.fp);
fstore.fp = NULL;
XX_httplib_remove_bad_file(conn, path);
}
file_size += (int64_t)n;
}
if ( ! end_of_key_value_pair_found ) {
used = next - buf;
memmove( buf, buf + (size_t)used, sizeof(buf) - (size_t)used );
buf_fill -= (int)used;
if ((size_t)buf_fill < (sizeof(buf) - 1)) {
size_t to_read = sizeof(buf) - 1 - (size_t)buf_fill;
r = httplib_read(conn, buf + (size_t)buf_fill, to_read);
if ( r < 0 ) return -1; /* read error */
if (r != (int)to_read) {
/*
* TODO: Create a function to get "all_data_read"
* from the conn object. All data is read if the
* Content-Length has been reached, or if chunked
* encoding is used and the end marker has been
* read, or if the connection has been closed.
*/
all_data_read = 1;
}
buf_fill += r;
buf[buf_fill] = 0;
if (buf_fill < 1) break;
val = buf;
}
}
} while ( ! end_of_key_value_pair_found );
if ( fstore.fp ) {
r = fclose(fstore.fp);
if ( r == 0 ) {
/*
* stored successfully
*/
field_stored( conn, path, file_size, fdh );
}
else {
httplib_cry( DEBUG_LEVEL_ERROR, conn->ctx, conn, "%s: Error saving file %s", __func__, path );
XX_httplib_remove_bad_file( conn, path );
}
fstore.fp = NULL;
}
/*
* Proceed to next entry
*/
used = next - buf;
memmove( buf, buf + (size_t)used, sizeof(buf) - (size_t)used );
buf_fill -= (int)used;
}
return field_count;
}
if ( ! httplib_strncasecmp( content_type, "MULTIPART/FORM-DATA;", 20) ) {
/*
* The form data is in the request body data, encoded as multipart
* content (see https://www.ietf.org/rfc/rfc1867.txt,
* https://www.ietf.org/rfc/rfc2388.txt).
*/
const char *boundary;
size_t bl;
ptrdiff_t used;
struct httplib_request_info part_header;
char *hbuf;
char *hend;
char *fbeg;
char *fend;
char *nbeg;
char *nend;
const char *content_disp;
const char *next;
memset( & part_header, 0, sizeof(part_header) );
/*
* Skip all spaces between MULTIPART/FORM-DATA; and BOUNDARY=
*/
bl = 20;
while (content_type[bl] == ' ') bl++;
/*
* There has to be a BOUNDARY definition in the Content-Type header
*/
if ( httplib_strncasecmp( content_type + bl, "BOUNDARY=", 9 ) ) {
/*
* Malformed request
*/
return -1;
}
boundary = content_type + bl + 9;
bl = strlen( boundary );
if ( bl + 800 > sizeof(buf) ) {
/*
* Sanity check: The algorithm can not work if bl >= sizeof(buf),
* and it will not work effectively, if the buf is only a few byte
* larger than bl, or it buf can not hold the multipart header
* plus the boundary.
* Check some reasonable number here, that should be fulfilled by
* any reasonable request from every browser. If it is not
* fulfilled, it might be a hand-made request, intended to
* interfere with the algorithm.
*/
return -1;
}
for (;;) {
size_t towrite;
size_t n;
int get_block;
r = httplib_read( conn, buf + (size_t)buf_fill, sizeof(buf) - 1 - (size_t)buf_fill );
if ( r < 0 ) return -1; /* read error */
buf_fill += r;
buf[buf_fill] = 0;
if ( buf_fill < 1 ) return -1; /* No data */
if ( buf[0] != '-' || buf[1] != '-' ) return -1; /* Malformed request */
if ( strncmp( buf + 2, boundary, bl ) ) return -1; /* Malformed request */
if ( buf[bl + 2] != '\r' || buf[bl + 3] != '\n' ) {
/*
* Every part must end with \r\n, if there is another part.
* The end of the request has an extra --
*/
if (((size_t)buf_fill != (size_t)(bl + 6)) || (strncmp(buf + bl + 2, "--\r\n", 4))) return -1; /* Malformed request */
/*
* End of the request
*/
break;
}
/*
* Next, we need to get the part header: Read until \r\n\r\n
*/
hbuf = buf + bl + 4;
hend = strstr(hbuf, "\r\n\r\n");
if ( hend == NULL ) return -1; /* Malformed request */
XX_httplib_parse_http_headers( &hbuf, &part_header );
if ( (hend + 2) != hbuf ) return -1; /* Malformed request */
/*
* Skip \r\n\r\n
*/
hend += 4;
/*
* According to the RFC, every part has to have a header field like:
* Content-Disposition: form-data; name="..."
*/
content_disp = XX_httplib_get_header( & part_header, "Content-Disposition" );
if ( ! content_disp ) return -1; /* Malformed request */
/*
* Get the mandatory name="..." part of the Content-Disposition
* header.
*/
nbeg = strstr( content_disp, "name=\"" );
if ( nbeg == NULL ) return -1; /* Malformed request */
nbeg += 6;
nend = strchr(nbeg, '\"');
if ( nend == NULL ) return -1; /* Malformed request */
/*
* Get the optional filename="..." part of the Content-Disposition
* header.
*/
fbeg = strstr( content_disp, "filename=\"" );
if ( fbeg != NULL ) {
fbeg += 10;
fend = strchr(fbeg, '\"');
if ( fend == NULL ) {
/*
* Malformed request (the filename field is optional, but if
* it exists, it needs to be terminated correctly).
*/
return -1;
}
/*
* TODO: check Content-Type
* Content-Type: application/octet-stream
*/
} else fend = fbeg;
memset( path, 0, sizeof(path) );
field_count++;
field_storage = url_encoded_field_found( conn, nbeg, (size_t)(nend - nbeg), fbeg, (size_t)(fend - fbeg), path, sizeof(path) - 1, fdh );
/*
* If the boundary is already in the buffer, get the address,
* otherwise next will be NULL.
*/
next = search_boundary( hbuf, (size_t)((buf - hbuf) + buf_fill), boundary, bl );
if ( field_storage == FORM_FIELD_STORAGE_STORE ) {
/*
* Store the content to a file
*/
if ( XX_httplib_fopen( conn, path, "wb", &fstore ) == 0 ) fstore.fp = NULL;
file_size = 0;
if ( ! fstore.fp ) httplib_cry( DEBUG_LEVEL_ERROR, conn->ctx, conn, "%s: Cannot create file %s", __func__, path );
}
get_block = 0;
while ( ! next ) {
/*
* Set "towrite" to the number of bytes available
* in the buffer
*/
towrite = (size_t)(buf - hend + buf_fill);
/*
* Subtract the boundary length, to deal with
* cases the boundary is only partially stored
* in the buffer.
*/
towrite -= bl + 4;
if (field_storage == FORM_FIELD_STORAGE_GET) {
unencoded_field_get(conn,
((get_block > 0) ? NULL : nbeg),
((get_block > 0) ? 0 : (size_t)(nend - nbeg)),
hend,
towrite,
fdh);
get_block++;
}
if ( field_storage == FORM_FIELD_STORAGE_STORE ) {
if (fstore.fp) {
/*
* Store the content of the buffer.
*/
n = (size_t)fwrite( hend, 1, towrite, fstore.fp );
if ( n != towrite || ferror( fstore.fp ) ) {
httplib_cry( DEBUG_LEVEL_ERROR, conn->ctx, conn, "%s: Cannot write file %s", __func__, path );
fclose( fstore.fp );
fstore.fp = NULL;
XX_httplib_remove_bad_file( conn, path );
}
file_size += (int64_t)n;
}
}
memmove( buf, hend + towrite, bl + 4 );
buf_fill = (int)(bl + 4);
hend = buf;
/*
* Read new data
*/
r = httplib_read( conn, buf + (size_t)buf_fill, sizeof(buf) - 1 - (size_t)buf_fill );
if ( r < 0 ) return -1; /* read error */
buf_fill += r;
buf[buf_fill] = 0;
if (buf_fill < 1) return -1; /* No data */
/*
* Find boundary
*/
next = search_boundary( buf, (size_t)buf_fill, boundary, bl );
}
towrite = (size_t)(next - hend);
if ( field_storage == FORM_FIELD_STORAGE_GET ) {
/*
* Call callback
*/
unencoded_field_get(conn,
((get_block > 0) ? NULL : nbeg),
((get_block > 0) ? 0 : (size_t)(nend - nbeg)),
hend,
towrite,
fdh);
}
if ( field_storage == FORM_FIELD_STORAGE_STORE ) {
if ( fstore.fp ) {
n = (size_t)fwrite( hend, 1, towrite, fstore.fp );
if ( n != towrite || ferror( fstore.fp ) ) {
httplib_cry( DEBUG_LEVEL_ERROR, conn->ctx, conn, "%s: Cannot write file %s", __func__, path );
fclose( fstore.fp );
fstore.fp = NULL;
XX_httplib_remove_bad_file( conn, path );
}
file_size += (int64_t)n;
}
}
if ( field_storage == FORM_FIELD_STORAGE_STORE ) {
if ( fstore.fp ) {
r = fclose( fstore.fp );
if ( r == 0 ) {
/*
* stored successfully
*/
field_stored( conn, path, file_size, fdh );
}
else {
httplib_cry( DEBUG_LEVEL_ERROR, conn->ctx, conn, "%s: Error saving file %s", __func__, path );
XX_httplib_remove_bad_file( conn, path );
}
fstore.fp = NULL;
}
}
if ( (field_storage & FORM_FIELD_STORAGE_ABORT) == FORM_FIELD_STORAGE_ABORT ) break; /* Stop parsing the request */
/*
* Remove from the buffer
*/
used = next - buf + 2;
memmove(buf, buf + (size_t)used, sizeof(buf) - (size_t)used);
buf_fill -= (int)used;
}
/*
* All parts handled
*/
return field_count;
}
/* Unknown Content-Type */
return -1;
}
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