#include <stdio.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.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 <stdint.h>
#include <assert.h>
#define ISspace(x) isspace((int)(x))
#define SERVER_STRING "Server: xxrlhttpd/0.1.0
"
#define STDIN 0
#define STDOUT 1
#define STDERR 2
#define String const char *
const int BUF_SIZE = 1024;
const int CONTENT_SIZE = 255;
// 头信息
struct HeaderInfo
{
int length;
String *head_str;
};
void accept_request(void *);
void headers(int, struct HeaderInfo *);
void cat(int, FILE *);
void error_die(String);
void execute_cgi(int, String, String , String);
int get_line(int, char *, int);
void serve_file(int, String);
int startup(u_short *);
struct HeaderInfo accpetInfo, notfoundInfo, badrequestInfo, unimplementedInfo, cannotexecuteInfo;
/**
* 初始化头信息
*/
void init_headers() {
accpetInfo.head_str = (String*)malloc(sizeof(String) * 4);
accpetInfo.head_str[0] = "HTTP/1.0 200 OK
";
accpetInfo.head_str[1] = SERVER_STRING;
accpetInfo.head_str[2] = "Content-Type: text/html
";
accpetInfo.head_str[3] = "
";
accpetInfo.length = 4;
notfoundInfo.head_str = (String *)malloc(sizeof(String) * 9);
notfoundInfo.head_str[0] = "HTTP/1.0 404 NOT FOUND
";
notfoundInfo.head_str[1] = SERVER_STRING;
notfoundInfo.head_str[2] = "Content-Type: text/html
";
notfoundInfo.head_str[3] = "
";
notfoundInfo.head_str[4] = "<HTML><TITLE>Not Found</TITLE>
";
notfoundInfo.head_str[5] = "<BODY><P>The server could not fulfill
";
notfoundInfo.head_str[6] = "your request because the resorce specified
";
notfoundInfo.head_str[7] = "is unavailable or nonexistent.</P>
";
notfoundInfo.head_str[8] = "</BODY></HTML>
";
notfoundInfo.length = 9;
badrequestInfo.head_str = (String *)malloc(sizeof(String) * 6);
badrequestInfo.head_str[0] = "HTTP/1.0 400 BAD REQUEST
";
badrequestInfo.head_str[1] = SERVER_STRING;
badrequestInfo.head_str[2] = "Content-type: text/html
";
badrequestInfo.head_str[3] = "
";
badrequestInfo.head_str[4] = "<P>Your browser send a bad request, ";
badrequestInfo.head_str[5] = "such as a POST without a Content-Length.</P>
";
badrequestInfo.length = 6;
unimplementedInfo.head_str = (String *)malloc(sizeof(String) * 6);
unimplementedInfo.head_str[0] = "HTTP/1.0 501 Method Not Implemented
";
unimplementedInfo.head_str[1] = SERVER_STRING;
unimplementedInfo.head_str[2] = "Content-Type: text/html
";
unimplementedInfo.head_str[3] = "
";
unimplementedInfo.head_str[4] = "<HTML><HEAD><TITLE>Method Not Implemented
";
unimplementedInfo.head_str[5] = "</BODY></HTML>
";
unimplementedInfo.length = 6;
cannotexecuteInfo.head_str = (String *)malloc(sizeof(String) * 4);
cannotexecuteInfo.head_str[0] = "HTTP/1.0 500 Internal Server Error
";
cannotexecuteInfo.head_str[1] = "Content-Type: text/html
";
cannotexecuteInfo.head_str[2] = "
";
cannotexecuteInfo.head_str[3] = "<P>Error prohibited CGI execution.</P>
";
cannotexecuteInfo.length = 4;
}
// 日志文件
FILE *logFile;
/**
* 处理一次请求
*
*/
void accept_request(void *arg)
{
int client = (intptr_t)arg;
char buf[BUF_SIZE];
size_t numchars;
char method[CONTENT_SIZE];
char url[CONTENT_SIZE];
char path[512];
size_t i, j;
struct stat st;
int cgi = 0;
char *query_string = NULL;
numchars = get_line(client, buf, sizeof(buf));
i = 0, j = 0;
while (!ISspace(buf[i]) && (i < sizeof(method) - 1))
{
method[i] = buf[i];
i++;
}
j = i;
method[i] = ' ';
if (strcasecmp(method, "GET") && strcasecmp(method, "POST"))
{
headers(client, &unimplementedInfo);
return;
}
if (strcasecmp(method, "POST") == 0)
cgi = 1;
i = 0;
while (ISspace(buf[j]) && (j < numchars))
j++;
while (!ISspace(buf[j]) && (i < sizeof(url) - 1) && (j < numchars))
{
url[i] = buf[j];
i++, j++;
}
url[i] = ' ';
if (strcasecmp(method, "GET") == 0)
{
query_string = url;
while ((*query_string != '?') && (*query_string != ' '))
query_string++;
if (*query_string == '?')
{
cgi = 1;
*query_string = ' ';
query_string++;
}
}
sprintf(path, "htpdocs%s", url);
if (path[strlen(path) - 1] == '/')
strcat(path, "index.html");
if (stat(path, &st) == -1) {
while ((numchars > 0) && strcmp("
", buf))
numchars = get_line(client, buf, sizeof(buf));
headers(client, ¬foundInfo);
}
else {
if ((st.st_mode & S_IFMT) == S_IFDIR)
strcat(path, "/index.html");
if ((st.st_mode & S_IXUSR) ||
(st.st_mode & S_IXGRP) ||
(st.st_mode & S_IXOTH) )
cgi = 1;
if (!cgi)
serve_file(client, path);
else
execute_cgi(client, path, method, query_string);
}
fprintf(logFile, "Accept a request, path: %s query:%s
", path, query_string);
fflush(logFile);
close(client);
}
/**
* 处理cgi请求
* @param：
* client: 客户端 描述符
* path: 请求的路径
* method： 请求的方法
* query_string: 参数字符串
*/
void execute_cgi(int client, String path, String method, String query_string)
{
char buf[BUF_SIZE];
int cgi_output[2];
int cgi_input[2];
pid_t pid;
int status;
int i;
char c;
int numchars = 1;
int content_length = -1;
buf[0] = 'A';
buf[1] = ' ';
if (strcasecmp(method, "GET") == 0)
while ((numchars > 0) && strcmp("
", buf))
numchars = get_line(client, buf, sizeof(buf));
else if (strcasecmp(method, "POST") == 0)
{
numchars = get_line(client, buf, sizeof(buf));
while ((numchars > 0) && strcmp("
", buf))
{
buf[15] = ' ';
if (strcasecmp(buf, "Content-Length:") == 0)
content_length = atoi(&(buf[16]));
numchars = get_line(client, buf, sizeof(buf));
}
if (content_length == -1)
{
headers(client, &badrequestInfo);
return;
}
}
else
{
// other request
}
// 创建管道和子进程
if (pipe(cgi_output) < 0 || pipe(cgi_input) < 0 || (pid = fork()) < 0)
{
headers(client, &cannotexecuteInfo);
return;
}
sprintf(buf, "HTTP/1.0 200 OK
");
send(client, buf, strlen(buf), 0);
if (pid == 0) /*child: CGI script*/
{
char meth_env[CONTENT_SIZE];
char query_env[CONTENT_SIZE];
char length_env[CONTENT_SIZE];
// 重定向标准输入输出， 子进程在output向父进程输出， 在input获取输入
dup2(cgi_output[1], STDOUT);
dup2(cgi_input[0], STDIN);
close(cgi_output[0]);
close(cgi_input[1]);
sprintf(meth_env, "REQUEST_METHOD=%s", method);
putenv(meth_env);
if (strcasecmp(method, "GET") == 0)
{
sprintf(query_env, "QUERY_STRING=%s", query_string);
putenv(query_env);
}
else
{
sprintf(length_env, "CONTENT_LENGTH=%d", content_length);
putenv(length_env);
}
// 执行脚本， 退出子进程
execl(path, NULL);
exit(0);
}
else
{ /* parent */
// 父进程 input向子进程输出， 在output获取输入
close(cgi_output[1]);
close(cgi_input[0]);
if (strcasecmp(method, "POST") == 0)
// 如果是post， 就向子进程写入长度为 content_length的数据
for (i = 0; i < content_length; ++i)
{
recv(client, &c, 1, 0);
write(cgi_input[1], &c, 1);
}
// 读取子进程的输出， 发送给socket
while (read(cgi_output[0], &c, 1))
send(client, &c, 1, 0);
// io完毕关闭描述符，等待子进程退出
close(cgi_output[0]);
close(cgi_input[1]);
waitpid(pid, &status, 0);
}
}
/**
* 响应文件
* @param:
* client: 客户端 描述符
* filename: 文件路径
*/
void serve_file(int client, String filename)
{
FILE *resource = NULL;
int numchars = 1;
char buf[BUF_SIZE];
// 获取 client 的数据
buf[0] = 'A';
buf[1] = ' ';
while ((numchars > 0) && strcmp("
", buf))
numchars = get_line(client, buf, sizeof(buf));
// 向流中写入 文件
resource = fopen(filename, "r");
if (resource == NULL)
headers(client, ¬foundInfo);
else
{
headers(client, &accpetInfo);
cat(client, resource);
}
fclose(resource);
}
/**
* 将文件中的数据传送到流中
* @param:
* client: 客户端 描述符
* resource: 文件
*/
void cat(int client, FILE* resource)
{
char buf[BUF_SIZE];
fgets(buf, sizeof(buf), resource);
while (!feof(resource))
{
send(client, buf, strlen(buf), 0);
fgets(buf, sizeof(buf), resource);
}
}
/**
* 出错后失败退出
* @param:
* sc: 错误信息
*/
void error_die(String sc)
{
perror(sc);
exit(1);
}
/**
* sock 流中获取一行
* @param:
* sock: sockfd 描述符
* buf: 缓冲流
* size: 最长读取长度
* @return:
* 读取到的字节数
*/
int get_line(int sock, char *buf, int size)
{
int i = 0;
char c = ' ';
int n;
while ((i < size - 1) && (c != '
'))
{
n = recv(sock, &c, 1, 0);
if (n > 0)
{
//
or
=>
if (c == '
')
{
n = recv(sock, &c, 1, MSG_PEEK);
if ((n > 0) && (c == '
'))
recv(sock, &c, 1, 0);
else
c = '
';
}
buf[i] = c;
i++;
}
else
break;
}
buf[i] = ' ';
return i;
}
/**
* 根据headerInfo 写入header信息
* @param:
* client: 客户端 描述符
* headerInfo: 响应的头信息
*
*/
void headers(int client, struct HeaderInfo *headerInfo)
{
char buf[BUF_SIZE];
int i = 0;
for (i = 0; i < headerInfo->length; ++i)
{
sprintf(buf, headerInfo->head_str[i]);
send(client, buf, strlen(buf), 0);
}
}
/**
* 创建socket 绑定到指定端口
* @param:
* port 端口号
* @return:
* socket 描述符
*/
int startup(u_short *port)
{
int httpd = 0;
int on = 1;
struct sockaddr_in name;
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);
if ((setsockopt(httpd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on))) < 0)
error_die("setsockopt failed");
if (bind(httpd, (struct sockaddr *)&name, sizeof(name)) < 0)
error_die("bind");
if (*port == 0)
{
socklen_t namelen = sizeof(name);
if (getsockname(httpd, (struct sockaddr *)&name, &namelen) == -1)
error_die("getsockname");
*port = ntohs(name.sin_port);
}
if (listen(httpd, 5) < 0)
error_die("listen");
return httpd;
}
int main(void)
{
int server_sock = -1;
u_short port = 4000;
int client_sock = -1;
struct sockaddr_in client_name;
socklen_t client_name_len = sizeof(client_name);
pthread_t newthread;
//prepare to start
init_headers();
server_sock = startup(&port);
printf("httpd running on port %d
", port);
logFile = fopen("log", "w");
// main loop
while (1)
{
// accpet a new request
client_sock = accept(server_sock,
(struct sockaddr *)&client_name,
&client_name_len);
if (client_sock == -1)
error_die("accept");
// send to a new thread
if (pthread_create(&newthread, NULL, (void *)accept_request, (void *)(intptr_t)client_sock) != 0)
perror("pthread_create");
}
// will never reach
fclose(logFile);
close(server_sock);
printf("Program exit.");
return 0;
}
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