#include <stdio.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <ctype.h>
#include <strings.h>
#include <string.h>
#include <sys/stat.h>
#include <pthread.h>
#include <sys/wait.h>
#include <stdlib.h>
#include <dirent.h>
#include <time.h>
#include <errno.h> // 添加errno头文件
#define ISspace
(x
) isspace
((int)(x
))
#define SERVER_STRING "Server: jdbhttpd/0.2.0\r\n"
// 函数声明
void* accept_request
(void *
);
void bad_request
(int);
void cat
(int,
FILE *
);
void error_die
(const char *
);
int get_line
(int, char
*, int);
void headers
(int, const char
*, const char *
);
void not_found
(int);
void serve_
file(int, const char *
);
void serve_
file_post
(int, const char *
);
int startup
(unsigned short *
);
void unimplemented
(int);
void forbidden
(int);
void serve_directory
(int, const char *
);
void url_decode
(char
*, const char *
);
const char *get_mime_type
(const char *
);
void log_request
(const char
*, const char
*, int);
void set_socket_timeout
(int,
int);
/**********************************************************************/
/* 处理客户端请求 */
/**********************************************************************/
void* accept_request
(void *pclient
)
{
int client = *
(int*
)pclient;
free
(pclient
);
set_socket_timeout
(client, 2
);
char buf[65536];
int numchars;
char method[255];
char url[255];
char path[1024]; // 增加路径长度
char decoded_url[1024]; // 存储解码后的URL
size_t i, j;
struct stat st;
// 获取请求的第一行
numchars = get_line
(client, buf, sizeof
(buf
));
i = 0; j = 0;
while
(!ISspace
(buf[j]
) &&
(i < sizeof
(method
) - 1
))
{
method[i] = buf[j];
i++; j++;
}
method[i] = '\0';
// 只支持GET和POST方法
if
(strcasecmp
(method, "GET"
) && strcasecmp
(method, "POST"
) && strcasecmp
(method, "OPTIONS"
))
{
unimplemented
(client
);
return
NULL;
}
// 读取URL
i = 0;
while
(ISspace
(buf[j]
) &&
(j < sizeof
(buf
)))
j++;
while
(!ISspace
(buf[j]
) &&
(i < sizeof
(url
) - 1
) &&
(j < sizeof
(buf
)))
{
url[i] = buf[j];
i++; j++;
}
url[i] = '\0';
// URL解码
url_decode
(decoded_url, url
);
// 记录请求日志
log_request
(method, decoded_url, client
);
// 构建文件路径（使用当前目录）
spr
intf
(path, "web%s", decoded_url
);
// 防止路径遍历攻击
if
(strstr
(path, ".."
)) {
forbidden
(client
);
close
(client
);
return
NULL;
}
// 处理目录请求
if
(path[strlen
(path
) - 1] == '/'
)
strcat
(path, "Index.html"
);
// 检查文件/目录是否存在
if
(stat
(path, &st
) == -1
) {
// 检查是否存在.html扩展名文件
char alt_path[1024];
spr
intf
(alt_path, "%s.html", path
);
if
(stat
(alt_path, &st
) == 0
) {
strcpy
(path, alt_path
);
} else {
/* 跳过剩余头部 */
while
((numchars > 0
) && strcmp
("\n", buf
))
numchars = get_line
(client, buf, sizeof
(buf
));
not_found
(client
);
close
(client
);
return
NULL;
}
}
// 如果是目录
if
((st.st_mode & S_IFMT
) == S_IFDIR
) {
// 检查目录中是否有index.html
char index_path[1024];
spr
intf
(index_path, "%s/Index.html", path
);
if
(stat
(index_path, &st
) == 0
) {
strcpy
(path, index_path
);
} else {
// 显示目录列表
serve_directory
(client, path
);
close
(client
);
return
NULL;
}
}
if
(strcasecmp
(method, "GET"
) == 0
)
{
serve_
file(client, path
);
}
else if
(strcasecmp
(method, "POST"
) == 0
)
{
serve_
file_post
(client, path
);
}
close
(client
);
return
NULL;
}
/**********************************************************************/
/* URL解码 */
/**********************************************************************/
void url_decode
(char *dest, const char *src
) {
char *p = dest;
while
(*src
) {
if
(*src == '%'
) {
if
(src[1] && src[2]
) {
char hex[3] = {src[1], src[2], '\0'};
*p++ =
(char
)strtol
(hex,
NULL, 16
);
src += 3;
} else {
*p++ = *src++;
}
} else if
(*src == '+'
) {
*p++ = ' ';
src++;
} else {
*p++ = *src++;
}
}
*p = '\0';
}
/**********************************************************************/
/* 获取MIME类型 */
/**********************************************************************/
const char *get_mime_type
(const char *
filename
) {
const char *dot = strrchr
(filename, '.'
);
if
(!dot
) return "text/plain";
if
(strcasecmp
(dot, ".html"
) == 0 || strcasecmp
(dot, ".htm"
) == 0
)
return "text/html";
if
(strcasecmp
(dot, ".css"
) == 0
)
return "text/css";
if
(strcasecmp
(dot, ".js"
) == 0
)
return "application/javascript";
if
(strcasecmp
(dot, ".jpg"
) == 0 || strcasecmp
(dot, ".jpeg"
) == 0
)
return "image/jpeg";
if
(strcasecmp
(dot, ".png"
) == 0
)
return "image/png";
if
(strcasecmp
(dot, ".gif"
) == 0
)
return "image/gif";
if
(strcasecmp
(dot, ".json"
) == 0
)
return "application/json";
if
(strcasecmp
(dot, ".ico"
) == 0
)
return "image/x-icon";
return "text/plain";
}
/**********************************************************************/
/* 记录请求日志 */
/**********************************************************************/
void log_request
(const char *method, const char *url,
int client
) {
time_t now = time
(NULL);
struct tm *tm = localtime
(&now
);
char timestamp[64];
strftime
(timestamp, sizeof
(timestamp
), "%Y-%m-%d %H:%M:%S", tm
);
struct sockaddr_in addr;
socklen_t addr_len = sizeof
(addr
);
getpeername
(client,
(struct sockaddr*
)&addr, &addr_len
);
char *ip = inet_ntoa
(addr.sin_addr
);
pr
intf
("[%s] %s %s %s\n", timestamp, ip, method, url
);
}
/**********************************************************************/
/* 处理目录列表 */
/**********************************************************************/
void serve_directory
(int client, const char *path
) {
char buf[4096];
// 发送HTTP头
spr
intf
(buf, "HTTP/1.0 200 OK\r\n"
);
send
(client, buf, strlen
(buf
), 0
);
spr
intf
(buf, SERVER_STRING
);
send
(client, buf, strlen
(buf
), 0
);
spr
intf
(buf, "Content-Type: text/html\r\n"
);
send
(client, buf, strlen
(buf
), 0
);
spr
intf
(buf, "\r\n"
);
send
(client, buf, strlen
(buf
), 0
);
// 发送HTML头部
spr
intf
(buf, "<html><head><title>Index of %s</title></head>", path
);
send
(client, buf, strlen
(buf
), 0
);
spr
intf
(buf, "<body><h1>Index of %s</h1><ul>", path
);
send
(client, buf, strlen
(buf
), 0
);
// 打开目录
DIR *dir = opendir
(path
);
if
(dir
) {
struct dirent *ent;
while
((ent = readdir
(dir
)) !=
NULL) {
// 跳过隐藏文件
if
(ent->d_name[0] == '.'
) continue;
char full_path[1024];
spr
intf
(full_path, "%s/%s", path, ent->d_name
);
struct stat st;
stat
(full_path, &st
);
char size_buf[32];
if
(S_ISDIR
(st.st_mode
)) {
strcpy
(size_buf, "[DIR]"
);
} else {
if
(st.st_size < 1024
) {
spr
intf
(size_buf, "%ld B", st.st_size
);
} else if
(st.st_size < 1024 * 1024
) {
spr
intf
(size_buf, "%.1f KB", st.st_size / 1024.0
);
} else {
spr
intf
(size_buf, "%.1f MB", st.st_size /
(1024.0 * 1024
));
}
}
spr
intf
(buf, "<li><a href=\"%s\">%s</a> - %s</li>",
ent->d_name, ent->d_name, size_buf
);
send
(client, buf, strlen
(buf
), 0
);
}
closedir
(dir
);
}
// 发送HTML尾部
spr
intf
(buf, "</ul></body></html>\r\n"
);
send
(client, buf, strlen
(buf
), 0
);
}
/**********************************************************************/
/* 400 Bad Request */
/**********************************************************************/
void bad_request
(int client
)
{
char buf[1024];
spr
intf
(buf, "HTTP/1.0 400 BAD REQUEST\r\n"
);
send
(client, buf, strlen
(buf
), 0
);
spr
intf
(buf, "Content-type: text/html\r\n"
);
send
(client, buf, strlen
(buf
), 0
);
spr
intf
(buf, "\r\n"
);
send
(client, buf, strlen
(buf
), 0
);
spr
intf
(buf, "<html><body><h1>400 Bad Request</h1></body></html>\r\n"
);
send
(client, buf, strlen
(buf
), 0
);
}
/**********************************************************************/
/* 403 Forbidden */
/**********************************************************************/
void forbidden
(int client
) {
char buf[1024];
spr
intf
(buf, "HTTP/1.0 403 Forbidden\r\n"
);
send
(client, buf, strlen
(buf
), 0
);
spr
intf
(buf, SERVER_STRING
);
send
(client, buf, strlen
(buf
), 0
);
spr
intf
(buf, "Content-Type: text/html\r\n"
);
send
(client, buf, strlen
(buf
), 0
);
spr
intf
(buf, "\r\n"
);
send
(client, buf, strlen
(buf
), 0
);
spr
intf
(buf, "<html><body><h1>403 Forbidden</h1><p>Access to this resource is denied.</p></body></html>\r\n"
);
send
(client, buf, strlen
(buf
), 0
);
}
/**********************************************************************/
/* 发送文件内容 */
/**********************************************************************/
void cat
(int client,
FILE *resource
)
{
char buf[65536];
fgets
(buf, sizeof
(buf
), resource
);
while
(!feof
(resource
))
{
send
(client, buf, strlen
(buf
), 0
);
fgets
(buf, sizeof
(buf
), resource
);
}
}
/**********************************************************************/
/* 错误处理 */
/**********************************************************************/
void error_die
(const char *sc
)
{
perror
(sc
);
exit
(1
);
}
/**********************************************************************/
/* 读取一行 */
/**********************************************************************/
int get_line
(int sock, char *buf,
int size
)
{
int i = 0;
char c = '\0';
int n;
while
((i < size - 1
) &&
(c != '\n'
))
{
n = recv
(sock, &c, 1, 0
);
if
(n > 0
)
{
if
(c == '\r'
)
{
n = recv
(sock, &c, 1, MSG_PEEK
);
if
((n > 0
) &&
(c == '\n'
))
recv
(sock, &c, 1, 0
);
else
c = '\n';
}
buf[i] = c;
i++;
}
else
c = '\n';
}
buf[i] = '\0';
return
(i
);
}
/**********************************************************************/
/* 发送HTTP头 */
/**********************************************************************/
void headers
(int client, const char *
filename, const char *content_type
)
{
char buf[1024];
(void
)filename; // 未使用
strcpy
(buf, "HTTP/1.0 200 OK\r\n"
);
send
(client, buf, strlen
(buf
), 0
);
strcpy
(buf, SERVER_STRING
);
send
(client, buf, strlen
(buf
), 0
);
spr
intf
(buf, "Content-Type: %s\r\n", content_type
);
send
(client, buf, strlen
(buf
), 0
);
strcpy
(buf, "\r\n"
);
send
(client, buf, strlen
(buf
), 0
);
}
/**********************************************************************/
/* 404 Not Found */
/**********************************************************************/
void not_found
(int client
)
{
char buf[1024];
spr
intf
(buf, "HTTP/1.0 404 NOT FOUND\r\n"
);
send
(client, buf, strlen
(buf
), 0
);
spr
intf
(buf, SERVER_STRING
);
send
(client, buf, strlen
(buf
), 0
);
spr
intf
(buf, "Content-Type: text/html\r\n"
);
send
(client, buf, strlen
(buf
), 0
);
spr
intf
(buf, "\r\n"
);
send
(client, buf, strlen
(buf
), 0
);
spr
intf
(buf, "<html><body><h1>404 Not Found</h1><p>The requested URL was not found on this server.</p></body></html>\r\n"
);
send
(client, buf, strlen
(buf
), 0
);
}
/**********************************************************************/
/* 服务静态文件（修复二进制文件处理） */
/**********************************************************************/
void serve_
file(int client, const char *
filename
)
{
FILE *resource =
NULL;
int numchars = 1;
char buf[1024];
size_t bytes_read;
long file_size;
// 丢弃请求头
buf[0] = 'A'; buf[1] = '\0';
while
((numchars > 0
) && strcmp
("\n", buf
))
numchars = get_line
(client, buf, sizeof
(buf
));
// 使用二进制模式打开文件
resource = fopen
(filename, "rb"
);
if
(resource ==
NULL) {
not_found
(client
);
return;
}
// 获取文件大小
fseek(resource, 0, SEEK_END
);
file_size = ftell
(resource
);
fseek(resource, 0, SEEK_SET
);
// 发送HTTP头
const char *content_type = get_mime_type
(filename
);
// 创建并发送头部
char header_buf[2048];
spr
intf
(header_buf, "HTTP/1.0 200 OK\r\n"
);
send
(client, header_buf, strlen
(header_buf
), 0
);
spr
intf
(header_buf, SERVER_STRING
);
send
(client, header_buf, strlen
(header_buf
), 0
);
spr
intf
(header_buf, "Content-Type: %s\r\n", content_type
);
send
(client, header_buf, strlen
(header_buf
), 0
);
spr
intf
(header_buf, "Content-Length: %ld\r\n",
file_size
);
send
(client, header_buf, strlen
(header_buf
), 0
);
spr
intf
(header_buf, "\r\n"
);
send
(client, header_buf, strlen
(header_buf
), 0
);
// 使用二进制模式发送文件内容
while
((bytes_read = fread
(buf, 1, sizeof
(buf
), resource
)) > 0
) {
ssize_t sent = send
(client, buf, bytes_read, MSG_NOSIGNAL
);
if
(sent < 0
) {
// 处理发送错误（如连接关闭）
break;
}
}
fclose
(resource
);
}
/**********************************************************************/
/* 服务静态文件（专为POST请求设计，包含请求体处理） */
/**********************************************************************/
void serve_
file_post
(int client, const char *
filename
)
{
FILE *resource =
NULL;
int numchars = 1;
char buf[1024];
size_t bytes_read;
long file_size;
size_t content_length = 0; // 用于存储请求体长度
// 1. 读取并处理请求头
while
((numchars > 0
) && strcmp
("\n", buf
) != 0
)
{
numchars = get_line
(client, buf, sizeof
(buf
));
// 解析Content-Length头部
if
(strncasecmp
(buf, "Content-Length:", 15
) == 0
) {
char *endptr;
unsigned
long temp = strtoul
(buf + 15, &endptr, 10
);
if
(endptr != buf + 15 && temp <= SIZE_MAX
) {
content_length =
(size_t
)temp;
}
}
}
// 2. 读取并丢弃请求体
if
(content_length > 0
) {
size_t total_read = 0;
struct timeval tv;
tv.tv_sec = 5; // 设置5秒超时
tv.tv_usec = 0;
setsockopt
(client, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof
(tv
));
while
(total_read < content_length
) {
size_t to_read = sizeof
(buf
);
size_t remaining = content_length - total_read;
if
(to_read > remaining
) {
to_read = remaining;
}
bytes_read = recv
(client, buf, to_read, 0
);
if
(bytes_read <= 0
) {
if
(bytes_read == 0
) {
break; // 连接关闭
} else if
(errno == EAGAIN || errno == EWOULDBLOCK
) {
fpr
intf
(stderr, "Request body read timeout\n"
);
break; // 超时
} else {
perror
("recv failed"
);
break; // 错误
}
}
total_read += bytes_read;
}
// 恢复默认超时设置
tv.tv_sec = 0;
tv.tv_usec = 0;
setsockopt
(client, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof
(tv
));
}
// 3. 打开并发送文件（与serve_
file相同）
resource = fopen
(filename, "rb"
);
if
(resource ==
NULL) {
not_found
(client
);
return;
}
// 获取文件大小
fseek(resource, 0, SEEK_END
);
file_size = ftell
(resource
);
fseek(resource, 0, SEEK_SET
);
// 发送HTTP头
const char *content_type = get_mime_type
(filename
);
char header_buf[2048];
spr
intf
(header_buf, "HTTP/1.0 200 OK\r\n"
);
send
(client, header_buf, strlen
(header_buf
), 0
);
spr
intf
(header_buf, SERVER_STRING
);
send
(client, header_buf, strlen
(header_buf
), 0
);
spr
intf
(header_buf, "Content-Type: %s\r\n", content_type
);
send
(client, header_buf, strlen
(header_buf
), 0
);
spr
intf
(header_buf, "Content-Length: %ld\r\n",
file_size
);
send
(client, header_buf, strlen
(header_buf
), 0
);
spr
intf
(header_buf, "\r\n"
);
send
(client, header_buf, strlen
(header_buf
), 0
);
// 发送文件内容
while
((bytes_read = fread
(buf, 1, sizeof
(buf
), resource
)) > 0
) {
ssize_t sent = send
(client, buf, bytes_read, MSG_NOSIGNAL
);
if
(sent < 0
) {
// 处理发送错误
break;
}
}
fclose
(resource
);
}
/**********************************************************************/
/* 启动服务器 */
/**********************************************************************/
int startup
(unsigned short *port
)
{
int httpd = 0;
struct sockaddr_in name;
/* 创建socket */
httpd = socket
(PF_INET, SOCK_STREAM, 0
);
if
(httpd == -1
)
error_die
("socket"
);
memset
(&name, 0, sizeof
(name
));
name.sin_family = AF_INET;
name.sin_port = htons
(*port
);
name.sin_addr.s_addr = htonl
(INADDR_ANY
);
/* 绑定地址 */
if
(bind
(httpd,
(struct sockaddr *
)&name, sizeof
(name
)) < 0
)
error_die
("bind"
);
/* 若预设端口为0，随机取用可用端口*/
if
(*port == 0
)
{
socklen_t namelen = sizeof
(name
);
if
(getsockname
(httpd,
(struct sockaddr *
)&name, &namelen
) == -1
)
error_die
("getsockname"
);
*port = ntohs
(name.sin_port
);
}
/* 监听连接 */
if
(listen
(httpd, 5
) < 0
)
error_die
("listen"
);
return
(httpd
);
}
/**********************************************************************/
/* 501 Not Implemented */
/**********************************************************************/
void unimplemented
(int client
)
{
char buf[1024];
spr
intf
(buf, "HTTP/1.0 501 Method Not Implemented\r\n"
);
send
(client, buf, strlen
(buf
), 0
);
spr
intf
(buf, SERVER_STRING
);
send
(client, buf, strlen
(buf
), 0
);
spr
intf
(buf, "Content-Type: text/html\r\n"
);
send
(client, buf, strlen
(buf
), 0
);
spr
intf
(buf, "\r\n"
);
send
(client, buf, strlen
(buf
), 0
);
spr
intf
(buf, "<html><body><h1>501 Not Implemented</h1><p>The requested method is not implemented.</p></body></html>\r\n"
);
send
(client, buf, strlen
(buf
), 0
);
}
// 设置套接字发送超时（在主循环accept后调用）
void set_socket_timeout
(int sockfd,
int timeout_sec
) {
struct timeval tv;
tv.tv_sec = timeout_sec; // 超时秒数
tv.tv_usec = 0;
if
(setsockopt
(sockfd, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof
(tv
)) < 0
) {
perror
("setsockopt SO_SNDTIMEO failed"
);
}
}
/**********************************************************************/
/* 主函数 */
/**********************************************************************/
int main
(void
)
{
int server_sock = -1;
unsigned short port = 8080;
int client_sock = -1;
struct sockaddr_in client_name;
socklen_t client_name_len = sizeof
(client_name
);
pthread_t newthread;
server_sock = startup
(&port
);
pr
intf
("HTTP server running on port %d\n", port
);
signal
(SIGPIPE, SIG_IGN
);
while
(1
)
{
/* 接受连接 */
client_sock = accept
(server_sock,
(struct sockaddr *
)&client_name,&client_name_len
);
if
(client_sock == -1
) {
perror
("accept"
);
continue; // 继续接受新连接，而不是退出
}
// 动态分配内存传递socket描述符
int *pclient = malloc
(sizeof
(int));
if
(!pclient
) {
perror
("malloc failed"
);
close
(client_sock
);
continue;
}
*pclient = client_sock;
// 创建线程处理请求（不再在主线程设置超时）
if
(pthread_create
(&newthread,
NULL, accept_request, pclient
) != 0
) {
perror
("pthread_create"
);
free
(pclient
);
close
(client_sock
);
} else {
// 分离线程，使其结束后自动释放资源
pthread_detach
(newthread
);
}
}
close
(server_sock
);
return
(0
);
}
以上是我通过 多线程方式 实现的webserver.
现在我想通过I/O多路复用的方式，实现同样的功能
请给出完整的实现
本文介绍了如何使用fseek函数在C语言中通过指定起点和偏移量来定位文件指针，并从目标位置读取数据。通过实例演示了如何在读取文件时实现精准定位。
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