【源码下载】http://sourceforge.net/projects/tinyhttpd/files/tinyhttpd%20source/tinyhttpd%200.1.0/tinyhttpd-0.1.0.tar.gz/download
【编译环境】ubuntu14.04+gcc
【运 行】工程利用了多线程，需要链接多线程的库libpthread.so；直接编译httpd.c源文件 $ gcc -o 程序名 源文件.c -lpthread 然后在浏览器输入: localhost:程序动态分配的端口号/index.html就可运行了。
请求头：
1 【GET】【http://localhost:59776/index.html】 2 Host: localhost:59776 3 User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux i686; rv:39.0) Gecko/20100101 Firefox/39.0 4 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 5 Accept-Language: zh-CN,zh;q=0.8,en-US;q=0.5,en;q=0.3 6 Accept-Encoding: gzip, deflate 7 Connection: keep-alive
响应头：
1 Content-Type: text/html 2 Server: jdbhttpd/0.1.0
【注 意】源代码中提示将多线程注释掉，注释掉后直接编译不能运行。不注释直接编译虽然会又warnning但可运行。
服务器端原理：
服务器端调用socket()建立socket套接字,调用bind()函数绑定IP和端口，调用listen()函数监听端口，等待浏览器发送URL，调用accept()函数接受数据，关闭套接字。
accept()函数中创建多线程，主线程继续等待，子线程处理http请求，解析浏览器发送的URL字符串，结束后新线程退出。
main():
1 int main(void)
2 {
3 int server_sock = -1;
4 u_short port = 0;
5 int client_sock = -1;
6 struct sockaddr_in client_name;
7 int client_name_len = sizeof(client_name);
8 pthread_t newthread;
9
10 server_sock = startup(&port); //传递port的地址到startup()函数
11 printf("httpd running on port %d\n", port);
12
13 while (1)
14 {
15 client_sock = accept(server_sock,
16 (struct sockaddr *)&client_name,
17 &client_name_len);
18 if (client_sock == -1)
19 error_die("accept");
20 /* accept_request(client_sock); */
21 if (pthread_create(&newthread , NULL, accept_request, client_sock) != 0)
22 perror("pthread_create");
23 }
24
25 close(server_sock);
26
27 return(0);
28 }
主函数调用startup()函数创建套接字。其中有一点是sockaddr和sockaddr_in的不同，总结是先创建sockaddr_in结构体，将该结构体中的各个变量赋值完后，在bind()或者accept()函数中将其转化为sockaddr结构体，因为两者所占内存空间一样可相互转化，另外两者所在头文件不一样，sockaddr在socket.h中，sockaddr_in在in.h中。
startup():
1 int startup(u_short *port)
2 {
3 int httpd = 0;
4 struct sockaddr_in name; //声明结构体
5
6 httpd = socket(PF_INET, SOCK_STREAM, 0); //创建套接字
7 if (httpd == -1)
8 error_die("socket");
9 memset(&name, 0, sizeof(name)); //初始化
10 name.sin_family = AF_INET; //协议簇赋值
11 name.sin_port = htons(*port);
12 name.sin_addr.s_addr = htonl(INADDR_ANY);
13 if (bind(httpd, (struct sockaddr *)&name, sizeof(name)) < 0) //绑定ＩＰ和端口
14 error_die("bind");
15 if (*port == 0) /* if dynamically allocating a port */
16 {
17 int namelen = sizeof(name);
18 if (getsockname(httpd, (struct sockaddr *)&name, &namelen) == -1)
19 error_die("getsockname");
20 *port = ntohs(name.sin_port);//动态分配端口
21 }
22 if (listen(httpd, 5) < 0) //监听套接字
23 error_die("listen");
24 return(httpd); //返回套接字
25 }
startup()函数返回套接字后创建多线程，多线程函数起始为accept_request()函数。
accept_request():
1 void accept_request(int client)
2 {
3 char buf[1024];
4 int numchars;
5 char method[255];
6 char url[255];
7 char path[512];
8 size_t i, j;
9 struct stat st;
10 int cgi = 0; /* becomes true if server decides this is a CGI
11 * program */
12 char *query_string = NULL;
13
14 numchars = get_line(client, buf, sizeof(buf));
15 i = 0; j = 0;
16 while (!ISspace(buf[j]) && (i < sizeof(method) - 1))
17 {
18 method[i] = buf[j];
19 i++; j++;
20 }
21 method[i] = ‘\0‘;
22 //判断请求方式
23 if (strcasecmp(method, "GET") && strcasecmp(method, "POST"))
24 {
25 unimplemented(client);
26 return;
27 }
28
29 if (strcasecmp(method, "POST") == 0)
30 cgi = 1;
31
32 i = 0;
33 while (ISspace(buf[j]) && (j < sizeof(buf)))
34 j++;
35 while (!ISspace(buf[j]) && (i < sizeof(url) - 1) && (j < sizeof(buf)))
36 {
37 url[i] = buf[j];
38 i++; j++;
39 }
40 url[i] = ‘\0‘;
41 //GET方式
42 if (strcasecmp(method, "GET") == 0)
43 {
44 query_string = url;
45 while ((*query_string != ‘?‘) && (*query_string != ‘\0‘))
46 query_string++;
47 if (*query_string == ‘?‘)
48 {
49 cgi = 1;
50 *query_string = ‘\0‘;
51 query_string++;
52 }
53 }
54 sprintf(path, "htdocs%s", url);//默认路径为工程下的htddocs文件夹下index.html
55 if (path[strlen(path) - 1] == ‘/‘)
56 strcat(path, "index.html");
57 if (stat(path, &st) == -1) {
58 while ((numchars > 0) && strcmp("\n", buf)) /* read & discard headers */
59 numchars = get_line(client, buf, sizeof(buf));
60 not_found(client);
61 }
62 else
63 {
64 if ((st.st_mode & S_IFMT) == S_IFDIR)
65 strcat(path, "/index.html");
66 if ((st.st_mode & S_IXUSR) ||
67 (st.st_mode & S_IXGRP) ||
68 (st.st_mode & S_IXOTH) )
69 cgi = 1;
70 if (!cgi)
71 serve_file(client, path); //处理静态页面
72 else
73 execute_cgi(client, path, method, query_string);
74 }
75
76 close(client);
77 }
处理静态文件函数serv_file():
发送一个文件到客户端，调用headers()发送响应头。调用cat()函数将一个文件的内容输出到socket。
1 void serve_file(int client, const char *filename)
2 {
3 FILE *resource = NULL;
4 int numchars = 1;
5 char buf[1024];
6
7 buf[0] = ‘A‘; buf[1] = ‘\0‘;
8 while ((numchars > 0) && strcmp("\n", buf)) /* read & discard headers */
9 //读取一行，将以\n或\r\n结束的字符串，转化为以\n\0字符结束
10 numchars = get_line(client, buf, sizeof(buf));
11
12 resource = fopen(filename, "r");
13 if (resource == NULL)
14 not_found(client);
15 else
16 {
17 //响应头
18 headers(client, filename);
19 cat(client, resource);
20 }
21 fclose(resource);
22 }
23 void headers(int client, const char *filename)
24 {
25 char buf[1024];
26 (void)filename; /* could use filename to determine file type */
27
28 strcpy(buf, "HTTP/1.0 200 OK\r\n");
29 send(client, buf, strlen(buf), 0);
30 strcpy(buf, SERVER_STRING);
31 send(client, buf, strlen(buf), 0);
32 sprintf(buf, "Content-Type: text/html\r\n");
33 send(client, buf, strlen(buf), 0);
34 strcpy(buf, "\r\n");
35 send(client, buf, strlen(buf), 0);
36 }
37 void cat(int client, FILE *resource)
38 {
39 char buf[1024];
40
41 fgets(buf, sizeof(buf), resource);
42 while (!feof(resource))
43 {
44 send(client, buf, strlen(buf), 0);
45 fgets(buf, sizeof(buf), resource);
46 }
47 }
时间： 2024-10-18 19:46:52