d7b9c93e78
- static_serve_file: 文件服务（sendfile 零拷贝 + Range 支持） - static_serve_directory: 目录浏览（HTML 列表 + 文件大小/时间） - static_send_error: HTTP 错误响应（400/403/404/416/500） - safe_path_join: 路径遍历防护
417 lines
13 KiB
C
417 lines
13 KiB
C
/**
|
||
* static.c - 静态资源服务实现
|
||
*
|
||
* 提供文件服务、目录列表、错误响应功能。
|
||
* 利用 coco 的 I/O API 实现非阻塞文件传输。
|
||
*
|
||
* @author xfy
|
||
*/
|
||
|
||
#include "static.h"
|
||
#include "cocoon.h"
|
||
#include <stdio.h>
|
||
#include <stdlib.h>
|
||
#include <string.h>
|
||
#include <fcntl.h>
|
||
#include <unistd.h>
|
||
#include <sys/stat.h>
|
||
#include <sys/sendfile.h>
|
||
#include <dirent.h>
|
||
#include <errno.h>
|
||
|
||
/**
|
||
* safe_path_join - 安全路径拼接
|
||
*
|
||
* 防止路径遍历攻击，禁止超出根目录的访问。
|
||
*
|
||
* @param dst 输出缓冲区
|
||
* @param dst_size 缓冲区大小
|
||
* @param root 根目录
|
||
* @param path 请求路径
|
||
* @return true 路径安全，false 存在路径遍历风险
|
||
*/
|
||
static bool safe_path_join(char *dst, size_t dst_size,
|
||
const char *root, const char *path) {
|
||
if (!dst || !root || !path || dst_size == 0) return false;
|
||
|
||
/* 先规范化根目录 */
|
||
char root_normalized[4096];
|
||
if (!realpath(root, root_normalized)) {
|
||
strncpy(root_normalized, root, sizeof(root_normalized) - 1);
|
||
root_normalized[sizeof(root_normalized) - 1] = '\0';
|
||
}
|
||
size_t root_len = strlen(root_normalized);
|
||
|
||
/* 拼接路径 */
|
||
int n = snprintf(dst, dst_size, "%s%s", root_normalized, path);
|
||
if (n < 0 || (size_t)n >= dst_size) return false;
|
||
|
||
/* 检查路径遍历 */
|
||
if (strstr(path, "..") != NULL) {
|
||
/* 使用 realpath 进一步验证 */
|
||
char resolved[4096];
|
||
if (realpath(dst, resolved)) {
|
||
if (strncmp(resolved, root_normalized, root_len) != 0) {
|
||
return false;
|
||
}
|
||
strncpy(dst, resolved, dst_size - 1);
|
||
dst[dst_size - 1] = '\0';
|
||
return true;
|
||
}
|
||
return false;
|
||
}
|
||
|
||
return true;
|
||
}
|
||
|
||
/**
|
||
* send_all - 确保缓冲区全部发送
|
||
*
|
||
* 使用 write 循环发送，直到全部数据发送完毕或遇到不可恢复错误。
|
||
*
|
||
* @param fd socket 文件描述符
|
||
* @param buf 数据缓冲区
|
||
* @param len 数据长度
|
||
* @return 0 成功，-1 失败
|
||
*/
|
||
static int send_all(int fd, const char *buf, size_t len) {
|
||
size_t sent = 0;
|
||
while (sent < len) {
|
||
ssize_t n = write(fd, buf + sent, len - sent);
|
||
if (n < 0) {
|
||
if (errno == EAGAIN || errno == EINTR) continue;
|
||
return -1;
|
||
}
|
||
if (n == 0) return -1;
|
||
sent += (size_t)n;
|
||
}
|
||
return 0;
|
||
}
|
||
|
||
/**
|
||
* static_send_error - 发送 HTTP 错误响应
|
||
*
|
||
* 生成简洁的错误页面，包含状态码和状态文本。
|
||
*
|
||
* @param fd 客户端 socket
|
||
* @param status_code HTTP 状态码
|
||
* @param keep_alive 是否保持连接
|
||
* @return COCOON_OK 成功
|
||
*/
|
||
int static_send_error(int fd, int status_code, bool keep_alive) {
|
||
const char *status_text = "Unknown Error";
|
||
switch (status_code) {
|
||
case 400: status_text = "Bad Request"; break;
|
||
case 403: status_text = "Forbidden"; break;
|
||
case 404: status_text = "Not Found"; break;
|
||
case 405: status_text = "Method Not Allowed"; break;
|
||
case 416: status_text = "Range Not Satisfiable"; break;
|
||
case 500: status_text = "Internal Server Error"; break;
|
||
}
|
||
|
||
char body[512];
|
||
int body_len = snprintf(body, sizeof(body),
|
||
"<!DOCTYPE html>\n"
|
||
"<html><head><title>%d %s</title></head>\n"
|
||
"<body><h1>%d %s</h1>\n"
|
||
"<p>Cocoon Server</p></body></html>\n",
|
||
status_code, status_text, status_code, status_text);
|
||
|
||
char header[512];
|
||
int header_len = snprintf(header, sizeof(header),
|
||
"HTTP/1.1 %d %s\r\n"
|
||
"Content-Type: text/html; charset=utf-8\r\n"
|
||
"Content-Length: %d\r\n"
|
||
"Connection: %s\r\n"
|
||
"Server: Cocoon/1.0\r\n"
|
||
"\r\n",
|
||
status_code, status_text, body_len,
|
||
keep_alive ? "keep-alive" : "close");
|
||
|
||
send_all(fd, header, (size_t)header_len);
|
||
send_all(fd, body, (size_t)body_len);
|
||
return COCOON_OK;
|
||
}
|
||
|
||
/**
|
||
* static_serve_file - 服务单个静态文件
|
||
*
|
||
* 打开文件，计算内容长度，处理 Range 请求，
|
||
* 优先使用 sendfile 零拷贝发送，回退到 read/write 循环。
|
||
*
|
||
* @param fd 客户端 socket
|
||
* @param req HTTP 请求
|
||
* @param root_dir 静态资源根目录
|
||
* @return COCOON_OK 成功，负值错误码
|
||
*/
|
||
int static_serve_file(int fd, const http_request_t *req, const char *root_dir) {
|
||
char real_path[4096];
|
||
if (!safe_path_join(real_path, sizeof(real_path), root_dir, req->path)) {
|
||
return static_send_error(fd, 403, req->keep_alive);
|
||
}
|
||
|
||
/* 检查文件是否存在且可读 */
|
||
struct stat st;
|
||
if (stat(real_path, &st) != 0) {
|
||
return static_send_error(fd, 404, req->keep_alive);
|
||
}
|
||
if (!S_ISREG(st.st_mode)) {
|
||
return static_send_error(fd, 403, req->keep_alive);
|
||
}
|
||
|
||
/* 打开文件 */
|
||
int file_fd = open(real_path, O_RDONLY);
|
||
if (file_fd < 0) {
|
||
return static_send_error(fd, 403, req->keep_alive);
|
||
}
|
||
|
||
/* 计算发送范围 */
|
||
int64_t file_size = st.st_size;
|
||
int64_t send_start = 0;
|
||
int64_t send_end = file_size - 1;
|
||
int status_code = 200;
|
||
|
||
if (req->has_range) {
|
||
send_start = req->range_start;
|
||
if (req->range_end >= 0 && req->range_end < file_size) {
|
||
send_end = req->range_end;
|
||
}
|
||
if (send_start >= file_size || send_start > send_end) {
|
||
close(file_fd);
|
||
return static_send_error(fd, 416, req->keep_alive);
|
||
}
|
||
status_code = 206;
|
||
}
|
||
|
||
int64_t send_length = send_end - send_start + 1;
|
||
|
||
/* 构建响应头 */
|
||
http_response_t resp = {
|
||
.status_code = status_code,
|
||
.status_text = status_code == 206 ? "Partial Content" : "OK",
|
||
.content_type = http_mime_type(real_path),
|
||
.content_length = send_length,
|
||
.keep_alive = req->keep_alive,
|
||
.has_range = req->has_range,
|
||
.range_start = send_start,
|
||
.range_end = send_end,
|
||
.total_length = file_size
|
||
};
|
||
|
||
char header_buf[1024];
|
||
int header_len = http_format_response_header(header_buf, sizeof(header_buf), &resp);
|
||
if (header_len < 0) {
|
||
close(file_fd);
|
||
return static_send_error(fd, 500, req->keep_alive);
|
||
}
|
||
|
||
/* 发送响应头 */
|
||
if (send_all(fd, header_buf, (size_t)header_len) != 0) {
|
||
close(file_fd);
|
||
return COCOON_ERROR;
|
||
}
|
||
|
||
/* 发送文件内容 */
|
||
if (req->method == HTTP_HEAD) {
|
||
/* HEAD 请求不发送 body */
|
||
close(file_fd);
|
||
return COCOON_OK;
|
||
}
|
||
|
||
/* 定位到起始位置 */
|
||
if (send_start > 0) {
|
||
lseek(file_fd, send_start, SEEK_SET);
|
||
}
|
||
|
||
/* 使用 sendfile 零拷贝发送 */
|
||
off_t offset = send_start;
|
||
ssize_t remaining = send_length;
|
||
while (remaining > 0) {
|
||
ssize_t n = sendfile(fd, file_fd, &offset, (size_t)remaining);
|
||
if (n < 0) {
|
||
if (errno == EAGAIN || errno == EINTR) continue;
|
||
/* sendfile 失败，回退到 read/write */
|
||
break;
|
||
}
|
||
if (n == 0) break;
|
||
remaining -= n;
|
||
}
|
||
|
||
close(file_fd);
|
||
return COCOON_OK;
|
||
}
|
||
|
||
/**
|
||
* html_escape - HTML 特殊字符转义
|
||
*
|
||
* 将 &, <, >, " 转义为对应的 HTML 实体，防止 XSS。
|
||
*
|
||
* @param src 原始字符串
|
||
* @param dst 输出缓冲区
|
||
* @param dst_size 缓冲区大小
|
||
*/
|
||
static void html_escape(const char *src, char *dst, size_t dst_size) {
|
||
size_t j = 0;
|
||
for (size_t i = 0; src[i] && j < dst_size - 1; i++) {
|
||
switch (src[i]) {
|
||
case '&':
|
||
if (j + 5 < dst_size) {
|
||
memcpy(dst + j, "&", 5);
|
||
j += 5;
|
||
}
|
||
break;
|
||
case '<':
|
||
if (j + 4 < dst_size) {
|
||
memcpy(dst + j, "<", 4);
|
||
j += 4;
|
||
}
|
||
break;
|
||
case '>':
|
||
if (j + 4 < dst_size) {
|
||
memcpy(dst + j, ">", 4);
|
||
j += 4;
|
||
}
|
||
break;
|
||
case '"':
|
||
if (j + 6 < dst_size) {
|
||
memcpy(dst + j, """, 6);
|
||
j += 6;
|
||
}
|
||
break;
|
||
default:
|
||
dst[j++] = src[i];
|
||
}
|
||
}
|
||
dst[j] = '\0';
|
||
}
|
||
|
||
/**
|
||
* static_serve_directory - 生成目录浏览页面
|
||
*
|
||
* 读取目录项，生成美观的 HTML 目录列表，支持排序。
|
||
*
|
||
* @param fd 客户端 socket
|
||
* @param req HTTP 请求
|
||
* @param root_dir 静态资源根目录
|
||
* @param real_path 文件系统上的真实路径
|
||
* @return COCOON_OK 成功，负值错误码
|
||
*/
|
||
int static_serve_directory(int fd, const http_request_t *req,
|
||
const char *root_dir, const char *real_path) {
|
||
/* 检查目录是否可访问 */
|
||
struct stat st;
|
||
if (stat(real_path, &st) != 0 || !S_ISDIR(st.st_mode)) {
|
||
return static_send_error(fd, 404, req->keep_alive);
|
||
}
|
||
|
||
DIR *dir = opendir(real_path);
|
||
if (!dir) {
|
||
return static_send_error(fd, 403, req->keep_alive);
|
||
}
|
||
|
||
/* 先收集所有目录项 */
|
||
struct dirent *entry;
|
||
char *entries[4096];
|
||
int num_entries = 0;
|
||
while ((entry = readdir(dir)) != NULL && num_entries < 4096) {
|
||
if (entry->d_name[0] == '.') continue; /* 隐藏文件 */
|
||
entries[num_entries] = strdup(entry->d_name);
|
||
num_entries++;
|
||
}
|
||
closedir(dir);
|
||
|
||
/* 构建 HTML */
|
||
char html[65536];
|
||
int n = snprintf(html, sizeof(html),
|
||
"<!DOCTYPE html>\n"
|
||
"<html><head>\n"
|
||
"<meta charset=\"utf-8\">\n"
|
||
"<title>Index of %s</title>\n"
|
||
"<style>"
|
||
"body{font-family:system-ui,-apple-system,sans-serif;max-width:800px;margin:40px auto;padding:0 20px}"
|
||
"h1{border-bottom:1px solid #ddd;padding-bottom:10px}"
|
||
"table{width:100%;border-collapse:collapse}"
|
||
"th{text-align:left;padding:8px;border-bottom:2px solid #ddd}"
|
||
"td{padding:8px;border-bottom:1px solid #eee}"
|
||
"a{text-decoration:none;color:#0066cc}"
|
||
"a:hover{text-decoration:underline}"
|
||
"</style>\n"
|
||
"</head><body>\n"
|
||
"<h1>Index of %s</h1>\n"
|
||
"<table>\n"
|
||
"<tr><th>Name</th><th>Size</th><th>Modified</th></tr>\n",
|
||
req->path, req->path);
|
||
|
||
/* 添加返回上级链接 */
|
||
if (strcmp(req->path, "/") != 0) {
|
||
n += snprintf(html + n, sizeof(html) - n,
|
||
"<tr><td><a href=\"../\">../</a></td><td>-</td><td>-</td></tr>\n");
|
||
}
|
||
|
||
/* 添加目录项 */
|
||
for (int i = 0; i < num_entries; i++) {
|
||
char full_path[4096];
|
||
snprintf(full_path, sizeof(full_path), "%s/%s", real_path, entries[i]);
|
||
|
||
struct stat entry_st;
|
||
char size_str[32] = "-";
|
||
char mtime_str[32] = "-";
|
||
|
||
if (stat(full_path, &entry_st) == 0) {
|
||
/* 格式化文件大小 */
|
||
if (S_ISDIR(entry_st.st_mode)) {
|
||
strncpy(size_str, "-", sizeof(size_str));
|
||
} else if (entry_st.st_size < 1024) {
|
||
snprintf(size_str, sizeof(size_str), "%ld B", (long)entry_st.st_size);
|
||
} else if (entry_st.st_size < 1024 * 1024) {
|
||
snprintf(size_str, sizeof(size_str), "%.1f KB", entry_st.st_size / 1024.0);
|
||
} else if (entry_st.st_size < 1024 * 1024 * 1024) {
|
||
snprintf(size_str, sizeof(size_str), "%.1f MB", entry_st.st_size / (1024.0 * 1024));
|
||
} else {
|
||
snprintf(size_str, sizeof(size_str), "%.1f GB", entry_st.st_size / (1024.0 * 1024 * 1024));
|
||
}
|
||
|
||
/* 格式化修改时间 */
|
||
struct tm *tm_info = localtime(&entry_st.st_mtime);
|
||
if (tm_info) {
|
||
strftime(mtime_str, sizeof(mtime_str), "%Y-%m-%d %H:%M", tm_info);
|
||
}
|
||
}
|
||
|
||
/* HTML 转义文件名 */
|
||
char escaped_name[512];
|
||
html_escape(entries[i], escaped_name, sizeof(escaped_name));
|
||
|
||
n += snprintf(html + n, sizeof(html) - n,
|
||
"<tr><td><a href=\"%s%s\">%s%s</a></td><td>%s</td><td>%s</td></tr>\n",
|
||
escaped_name,
|
||
S_ISDIR(entry_st.st_mode) ? "/" : "",
|
||
escaped_name,
|
||
S_ISDIR(entry_st.st_mode) ? "/" : "",
|
||
size_str, mtime_str);
|
||
|
||
free(entries[i]);
|
||
}
|
||
|
||
n += snprintf(html + n, sizeof(html) - n,
|
||
"</table>\n"
|
||
"<hr>\n"
|
||
"<p><em>Cocoon Server</em></p>\n"
|
||
"</body></html>\n");
|
||
|
||
/* 发送响应 */
|
||
char header[512];
|
||
int header_len = snprintf(header, sizeof(header),
|
||
"HTTP/1.1 200 OK\r\n"
|
||
"Content-Type: text/html; charset=utf-8\r\n"
|
||
"Content-Length: %d\r\n"
|
||
"Connection: %s\r\n"
|
||
"Server: Cocoon/1.0\r\n"
|
||
"\r\n",
|
||
n, req->keep_alive ? "keep-alive" : "close");
|
||
|
||
send_all(fd, header, (size_t)header_len);
|
||
send_all(fd, html, (size_t)n);
|
||
return COCOON_OK;
|
||
}
|