static.c File Reference

Static file serving middleware implementation. More...

#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>
#include <uv.h>
#include "csilk/csilk.h"
#include "csilk/core/internal.h"

Include dependency graph for static.c:

Functions
static const char *	get_mime_type (const char *path)
	Internal helper to get MIME type from file path.
static void	set_range_response (csilk_ctx_t *c, int fd, size_t size, const char *mime_type)
	Setup a file response with optional 206 Partial Content for range requests.
static void	static_work_cb (uv_work_t *req)
	libuv work callback: resolve and open the requested static file.
static void	file_work_cb (uv_work_t *req)
	libuv work callback: open and stat a specific file.
static void	static_after_work_cb (uv_work_t *req, int status)
	libuv after-work callback: send the static file response.
void	csilk_static (csilk_ctx_t *c, const char *root_dir)
	Serve static files from a local directory (async, offloaded).
void	csilk_file (csilk_ctx_t *c, const char *file_path)
	Serve a specific file (async, offloaded).

Detailed Description

Static file serving middleware implementation.

Copyright

MIT License

Function Documentation

csilk_file()

void csilk_file	(	csilk_ctx_t *	c,
		const char *	file_path
	)

Serve a specific file (async, offloaded).

Serve a specific file from the local filesystem.

Offloads file open/stat operations to the libuv thread pool. The response is sent via the normal _csilk_send_response() path using zero-copy.

Parameters

c	The request context.
file_path	Path to the file to serve.

csilk_static()

void csilk_static	(	csilk_ctx_t *	c,
		const char *	root_dir
	)

Serve static files from a local directory (async, offloaded).

Serve static files from a local directory.

Offloads file resolution, path traversal checks, and file open/stat operations to the libuv thread pool. The response is sent via the normal _csilk_send_response() path, which sends the file using platform-specific zero-copy mechanisms (e.g. sendfile on Linux).

The URL prefix is automatically stripped from the request path before resolving against root_dir — the "static_prefix" must be set via csilk_set(c, "static_prefix", prefix_string) before calling this function.

Parameters

c	The request context.
root_dir	Absolute or relative path to the static file root directory. Must not be NULL.

Note

The prefix is configured separately via csilk_set(c, "static_prefix", ...) NOT via this function's parameters.

Warning

Path traversal attacks are mitigated via realpath() comparison. Ensure root_dir does not contain symlinks that could be exploited.

file_work_cb()

static void file_work_cb ( uv_work_t *  req )

static

libuv work callback: open and stat a specific file.

Runs in the libuv thread pool. Opens the file specified by the "serve_file_path" context property and sets up a range response.

Parameters

req	libuv work request. req->data points to the csilk_ctx_t.

get_mime_type()

static const char * get_mime_type ( const char *  path )

static

Internal helper to get MIME type from file path.

Maps the file extension to a MIME type string. Currently supports .html, .css, and .js. All other extensions (including files without an extension) return application/octet-stream.

Parameters

path	The file path to evaluate.

Returns

A static string pointer to the MIME type. Must NOT be freed.

set_range_response()

static void set_range_response ( csilk_ctx_t *  c, int  fd, size_t  size, const char *  mime_type  )

static

Setup a file response with optional 206 Partial Content for range requests.

Examines the incoming "Range" header. If absent or malformed, the entire file is served with a 200 OK status. If a valid "bytes=" range is present, a 206 Partial Content response is configured with the appropriate Content-Range header.

In both cases, the file descriptor, offset, and size are stored on the context for subsequent async sending.

Parameters

c	The request context.
fd	Open file descriptor for the requested file.
size	Total file size in bytes.
mime_type	The MIME type string for Content-Type header.

Note

On range errors (non-numeric range, start > end, or unsatisfiable), a 416 Range Not Satisfiable status is set and the FD is closed.

static_after_work_cb()

static void static_after_work_cb ( uv_work_t *  req, int  status  )

static

libuv after-work callback: send the static file response.

Runs on the event loop after static_work_cb completes. If the client connection is still alive (_internal_client is non-NULL), it triggers _csilk_send_response() to transmit the file (using sendfile or chunked I/O depending on the platform).

Parameters

req	libuv work request. req->data points to the csilk_ctx_t.
status	Work status — 0 on success, negative on cancellation.

static_work_cb()

static void static_work_cb ( uv_work_t *  req )

static

libuv work callback: resolve and open the requested static file.

Runs on the libuv thread pool. Resolves the requested path relative to the configured root directory, performs a path traversal check (ensuring the resolved path stays within the root), opens the file, stats it, determines the MIME type, and configures the response (including any range handling). The actual file content is sent later in static_after_work_cb via _csilk_send_response.

Parameters

req	libuv work request. req->data points to the csilk_ctx_t. The context must have "static_root" and "static_prefix" set via csilk_set().

Note

Path traversal protection uses realpath() to canonicalize both root and requested paths, then verifies the requested path starts with the root prefix.