lighttpd 1.4.x https://www.lighttpd.net/
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#include "first.h"
/**
* the HTTP chunk-API
*
*
*/
#include "http_chunk.h"
#include "base.h"
#include "chunk.h"
[core] open fd when appending file to cq (fixes #2655) http_chunk_append_file() opens fd when appending file to chunkqueue. Defers calculation of content length until response is finished. This reduces race conditions pertaining to stat() and then (later) open(), when the result of the stat() was used for Content-Length or to generate chunked headers. Note: this does not change how lighttpd handles files that are modified in-place by another process after having been opened by lighttpd -- don't do that. This *does* improve handling of files that are frequently modified via a temporary file and then atomically renamed into place. mod_fastcgi has been modified to use http_chunk_append_file_range() with X-Sendfile2 and will open the target file multiple times if there are multiple ranges. Note: (future todo) not implemented for chunk.[ch] interfaces used by range requests in mod_staticfile or by mod_ssi. Those uses could lead to too many open fds. For mod_staticfile, limits should be put in place for max number of ranges accepted by mod_staticfile. For mod_ssi, limits would need to be placed on the maximum number of includes, and the primary SSI file split across lots of SSI directives should either copy the pieces or perhaps chunk.h could be extended to allow for an open fd to be shared across multiple chunks. Doing either of these would improve the performance of SSI since they would replace many file opens on the pieces of the SSI file around the SSI directives. x-ref: "Serving a file that is getting updated can cause an empty response or incorrect content-length error" https://redmine.lighttpd.net/issues/2655 github: Closes #49
6 years ago
#include "stat_cache.h"
#include "fdevent.h"
#include "log.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
static void http_chunk_len_append(chunkqueue * const cq, uintmax_t len) {
char buf[24]; /* 64-bit (8 bytes) is 16 hex chars (+2 \r\n, +1 \0 = 19) */
#if 0
buffer b = { buf, 0, sizeof(buf) };
buffer_append_uint_hex(&b, len);
buffer_append_string_len(&b, CONST_STR_LEN("\r\n"));
chunkqueue_append_mem(cq, b.ptr, b.used-1);
#else
int i = (int)(sizeof(buf));
buf[--i] = '\n';
buf[--i] = '\r';
do { buf[--i] = "0123456789abcdef"[len & 0x0F]; } while (len >>= 4);
chunkqueue_append_mem(cq, buf+i, sizeof(buf)-i);
#endif
}
static int http_chunk_len_append_tempfile(chunkqueue * const cq, uintmax_t len, log_error_st * const errh) {
char buf[24]; /* 64-bit (8 bytes) is 16 hex chars (+2 \r\n, +1 \0 = 19) */
#if 0
buffer b = { buf, 0, sizeof(buf) };
buffer_append_uint_hex(&b, len);
buffer_append_string_len(&b, CONST_STR_LEN("\r\n"));
return chunkqueue_append_mem_to_tempfile(cq, b.ptr, b.used-1, errh);
#else
int i = (int)(sizeof(buf));
buf[--i] = '\n';
buf[--i] = '\r';
do { buf[--i] = "0123456789abcdef"[len & 0x0F]; } while (len >>= 4);
return chunkqueue_append_mem_to_tempfile(cq, buf+i, sizeof(buf)-i, errh);
#endif
}
static int http_chunk_append_file_open_fstat(const request_st * const r, const buffer * const fn, struct stat * const st) {
return
(r->conf.follow_symlink
|| !stat_cache_path_contains_symlink(fn, r->conf.errh))
? stat_cache_open_rdonly_fstat(fn, st, r->conf.follow_symlink)
: -1;
[core] open fd when appending file to cq (fixes #2655) http_chunk_append_file() opens fd when appending file to chunkqueue. Defers calculation of content length until response is finished. This reduces race conditions pertaining to stat() and then (later) open(), when the result of the stat() was used for Content-Length or to generate chunked headers. Note: this does not change how lighttpd handles files that are modified in-place by another process after having been opened by lighttpd -- don't do that. This *does* improve handling of files that are frequently modified via a temporary file and then atomically renamed into place. mod_fastcgi has been modified to use http_chunk_append_file_range() with X-Sendfile2 and will open the target file multiple times if there are multiple ranges. Note: (future todo) not implemented for chunk.[ch] interfaces used by range requests in mod_staticfile or by mod_ssi. Those uses could lead to too many open fds. For mod_staticfile, limits should be put in place for max number of ranges accepted by mod_staticfile. For mod_ssi, limits would need to be placed on the maximum number of includes, and the primary SSI file split across lots of SSI directives should either copy the pieces or perhaps chunk.h could be extended to allow for an open fd to be shared across multiple chunks. Doing either of these would improve the performance of SSI since they would replace many file opens on the pieces of the SSI file around the SSI directives. x-ref: "Serving a file that is getting updated can cause an empty response or incorrect content-length error" https://redmine.lighttpd.net/issues/2655 github: Closes #49
6 years ago
}
static int http_chunk_append_read_fd_range(request_st * const r, const buffer * const fn, const int fd, off_t offset, off_t len) {
/* note: this routine should not be used for range requests
* unless the total size of ranges requested is small */
/* note: future: could read into existing MEM_CHUNK in cq->last if
* there is sufficient space, but would need to adjust for existing
* offset in for cq->bytes_in in chunkqueue_append_buffer_commit() */
UNUSED(fn);
chunkqueue * const cq = r->write_queue;
if (r->resp_send_chunked)
http_chunk_len_append(cq, (uintmax_t)len);
if (0 != offset && -1 == lseek(fd, offset, SEEK_SET)) return -1;
buffer * const b = chunkqueue_append_buffer_open_sz(cq, len+2);
ssize_t rd;
offset = 0;
do {
rd = read(fd, b->ptr+offset, len-offset);
} while (rd > 0 ? (offset += rd, len -= rd) : errno == EINTR);
buffer_commit(b, offset);
if (r->resp_send_chunked)
buffer_append_string_len(b, CONST_STR_LEN("\r\n"));
chunkqueue_append_buffer_commit(cq);
return (rd >= 0) ? 0 : -1;
}
static void http_chunk_append_file_fd_range(request_st * const r, const buffer * const fn, const int fd, const off_t offset, const off_t len) {
chunkqueue * const cq = r->write_queue;
fix buffer, chunk and http_chunk API * remove unused structs and functions (buffer_array, read_buffer) * change return type from int to void for many functions, as the return value (indicating error/success) was never checked, and the function would only fail on programming errors and not on invalid input; changed functions to use force_assert instead of returning an error. * all "len" parameters now are the real size of the memory to be read. the length of strings is given always without the terminating 0. * the "buffer" struct still counts the terminating 0 in ->used, provide buffer_string_length() to get the length of a string in a buffer. unset config "strings" have used == 0, which is used in some places to distinguish unset values from "" (empty string) values. * most buffer usages should now use it as string container. * optimise some buffer copying by "moving" data to other buffers * use (u)intmax_t for generic int-to-string functions * remove unused enum values: UNUSED_CHUNK, ENCODING_UNSET * converted BUFFER_APPEND_SLASH to inline function (no macro feature needed) * refactor: create chunkqueue_steal: moving (partial) chunks into another queue * http_chunk: added separate function to terminate chunked body instead of magic handling in http_chunk_append_mem(). http_chunk_append_* now handle empty chunks, and never terminate the chunked body. From: Stefan Bühler <stbuehler@web.de> git-svn-id: svn://svn.lighttpd.net/lighttpd/branches/lighttpd-1.4.x@2975 152afb58-edef-0310-8abb-c4023f1b3aa9
7 years ago
if (r->resp_send_chunked)
http_chunk_len_append(cq, (uintmax_t)len);
chunkqueue_append_file_fd(cq, fn, fd, offset, len);
if (r->resp_send_chunked)
chunkqueue_append_mem(cq, CONST_STR_LEN("\r\n"));
}
int http_chunk_append_file_range(request_st * const r, const buffer * const fn, const off_t offset, off_t len) {
struct stat st;
const int fd = http_chunk_append_file_open_fstat(r, fn, &st);
if (fd < 0) return -1;
[core] open fd when appending file to cq (fixes #2655) http_chunk_append_file() opens fd when appending file to chunkqueue. Defers calculation of content length until response is finished. This reduces race conditions pertaining to stat() and then (later) open(), when the result of the stat() was used for Content-Length or to generate chunked headers. Note: this does not change how lighttpd handles files that are modified in-place by another process after having been opened by lighttpd -- don't do that. This *does* improve handling of files that are frequently modified via a temporary file and then atomically renamed into place. mod_fastcgi has been modified to use http_chunk_append_file_range() with X-Sendfile2 and will open the target file multiple times if there are multiple ranges. Note: (future todo) not implemented for chunk.[ch] interfaces used by range requests in mod_staticfile or by mod_ssi. Those uses could lead to too many open fds. For mod_staticfile, limits should be put in place for max number of ranges accepted by mod_staticfile. For mod_ssi, limits would need to be placed on the maximum number of includes, and the primary SSI file split across lots of SSI directives should either copy the pieces or perhaps chunk.h could be extended to allow for an open fd to be shared across multiple chunks. Doing either of these would improve the performance of SSI since they would replace many file opens on the pieces of the SSI file around the SSI directives. x-ref: "Serving a file that is getting updated can cause an empty response or incorrect content-length error" https://redmine.lighttpd.net/issues/2655 github: Closes #49
6 years ago
if (-1 == len) {
if (offset >= st.st_size) {
close(fd);
return (offset == st.st_size) ? 0 : -1;
}
len = st.st_size - offset;
}
else if (st.st_size - offset < len) {
close(fd);
return -1;
}
[core] open fd when appending file to cq (fixes #2655) http_chunk_append_file() opens fd when appending file to chunkqueue. Defers calculation of content length until response is finished. This reduces race conditions pertaining to stat() and then (later) open(), when the result of the stat() was used for Content-Length or to generate chunked headers. Note: this does not change how lighttpd handles files that are modified in-place by another process after having been opened by lighttpd -- don't do that. This *does* improve handling of files that are frequently modified via a temporary file and then atomically renamed into place. mod_fastcgi has been modified to use http_chunk_append_file_range() with X-Sendfile2 and will open the target file multiple times if there are multiple ranges. Note: (future todo) not implemented for chunk.[ch] interfaces used by range requests in mod_staticfile or by mod_ssi. Those uses could lead to too many open fds. For mod_staticfile, limits should be put in place for max number of ranges accepted by mod_staticfile. For mod_ssi, limits would need to be placed on the maximum number of includes, and the primary SSI file split across lots of SSI directives should either copy the pieces or perhaps chunk.h could be extended to allow for an open fd to be shared across multiple chunks. Doing either of these would improve the performance of SSI since they would replace many file opens on the pieces of the SSI file around the SSI directives. x-ref: "Serving a file that is getting updated can cause an empty response or incorrect content-length error" https://redmine.lighttpd.net/issues/2655 github: Closes #49
6 years ago
http_chunk_append_file_fd_range(r, fn, fd, offset, len);
return 0;
[core] open fd when appending file to cq (fixes #2655) http_chunk_append_file() opens fd when appending file to chunkqueue. Defers calculation of content length until response is finished. This reduces race conditions pertaining to stat() and then (later) open(), when the result of the stat() was used for Content-Length or to generate chunked headers. Note: this does not change how lighttpd handles files that are modified in-place by another process after having been opened by lighttpd -- don't do that. This *does* improve handling of files that are frequently modified via a temporary file and then atomically renamed into place. mod_fastcgi has been modified to use http_chunk_append_file_range() with X-Sendfile2 and will open the target file multiple times if there are multiple ranges. Note: (future todo) not implemented for chunk.[ch] interfaces used by range requests in mod_staticfile or by mod_ssi. Those uses could lead to too many open fds. For mod_staticfile, limits should be put in place for max number of ranges accepted by mod_staticfile. For mod_ssi, limits would need to be placed on the maximum number of includes, and the primary SSI file split across lots of SSI directives should either copy the pieces or perhaps chunk.h could be extended to allow for an open fd to be shared across multiple chunks. Doing either of these would improve the performance of SSI since they would replace many file opens on the pieces of the SSI file around the SSI directives. x-ref: "Serving a file that is getting updated can cause an empty response or incorrect content-length error" https://redmine.lighttpd.net/issues/2655 github: Closes #49
6 years ago
}
int http_chunk_append_file(request_st * const r, const buffer * const fn) {
struct stat st;
const int fd = http_chunk_append_file_open_fstat(r, fn, &st);
if (fd < 0) return -1;
http_chunk_append_file_fd(r, fn, fd, st.st_size);
return 0;
}
int http_chunk_append_file_fd(request_st * const r, const buffer * const fn, const int fd, const off_t sz) {
if (sz > 32768) {
http_chunk_append_file_fd_range(r, fn, fd, 0, sz);
return 0;
}
/*(read small files into memory)*/
int rc = (0 != sz) ? http_chunk_append_read_fd_range(r,fn,fd,0,sz) : 0;
close(fd);
return rc;
}
static int http_chunk_append_to_tempfile(request_st * const r, const char * const mem, const size_t len) {
chunkqueue * const cq = r->write_queue;
log_error_st * const errh = r->conf.errh;
if (r->resp_send_chunked
&& 0 != http_chunk_len_append_tempfile(cq, len, errh))
return -1;
if (0 != chunkqueue_append_mem_to_tempfile(cq, mem, len, errh))
return -1;
if (r->resp_send_chunked
&& 0 !=
chunkqueue_append_mem_to_tempfile(cq, CONST_STR_LEN("\r\n"), errh))
return -1;
return 0;
}
static int http_chunk_append_cq_to_tempfile(request_st * const r, chunkqueue * const src, const size_t len) {
chunkqueue * const cq = r->write_queue;
log_error_st * const errh = r->conf.errh;
if (r->resp_send_chunked
&& 0 != http_chunk_len_append_tempfile(cq, len, errh))
return -1;
if (0 != chunkqueue_steal_with_tempfiles(cq, src, len, errh))
return -1;
if (r->resp_send_chunked
&& 0 !=
chunkqueue_append_mem_to_tempfile(cq, CONST_STR_LEN("\r\n"), errh))
return -1;
return 0;
}
__attribute_pure__
static int http_chunk_uses_tempfile(const request_st * const r, const chunkqueue * const cq, const size_t len) {
/* current usage does not append_mem or append_buffer after appending
* file, so not checking if users of this interface have appended large
* (references to) files to chunkqueue, which would not be in memory
* (but included in calculation for whether or not to use temp file) */
/*(allow slightly larger mem use if FDEVENT_STREAM_RESPONSE_BUFMIN
* to reduce creation of temp files when backend producer will be
* blocked until more data is sent to network to client)*/
const chunk * const c = cq->last;
return
((c && c->type == FILE_CHUNK && c->file.is_temp)
|| cq->bytes_in - cq->bytes_out + len
> ((r->conf.stream_response_body & FDEVENT_STREAM_RESPONSE_BUFMIN)
? 128*1024
: 64*1024));
}
int http_chunk_append_buffer(request_st * const r, buffer * const mem) {
size_t len = buffer_string_length(mem);
if (0 == len) return 0;
chunkqueue * const cq = r->write_queue;
if (http_chunk_uses_tempfile(r, cq, len))
return http_chunk_append_to_tempfile(r, mem->ptr, len);
if (r->resp_send_chunked)
http_chunk_len_append(cq, len);
/*(chunkqueue_append_buffer() might steal buffer contents)*/
chunkqueue_append_buffer(cq, mem);
if (r->resp_send_chunked)
chunkqueue_append_mem(cq, CONST_STR_LEN("\r\n"));
return 0;
}
int http_chunk_append_mem(request_st * const r, const char * const mem, const size_t len) {
if (0 == len) return 0;
force_assert(NULL != mem);
chunkqueue * const cq = r->write_queue;
if (http_chunk_uses_tempfile(r, cq, len))
return http_chunk_append_to_tempfile(r, mem, len);
if (r->resp_send_chunked)
http_chunk_len_append(cq, len);
chunkqueue_append_mem(cq, mem, len);
if (r->resp_send_chunked)
chunkqueue_append_mem(cq, CONST_STR_LEN("\r\n"));
return 0;
}
int http_chunk_transfer_cqlen(request_st * const r, chunkqueue * const src, const size_t len) {
if (0 == len) return 0;
chunkqueue * const cq = r->write_queue;
if (http_chunk_uses_tempfile(r, cq, len))
return http_chunk_append_cq_to_tempfile(r, src, len);
if (r->resp_send_chunked)
http_chunk_len_append(cq, len);
chunkqueue_steal(cq, src, len);
if (r->resp_send_chunked)
chunkqueue_append_mem(cq, CONST_STR_LEN("\r\n"));
return 0;
}
void http_chunk_close(request_st * const r) {
if (r->resp_send_chunked)
chunkqueue_append_mem(r->write_queue, CONST_STR_LEN("0\r\n\r\n"));
}