From 8fb56a9b579d32d5631701addc1a99615f8e2037 Mon Sep 17 00:00:00 2001 From: aixiao Date: Wed, 22 Aug 2018 11:16:16 +0000 Subject: [PATCH] =?UTF-8?q?0.1=20=09Makefile=E6=96=87=E4=BB=B6=EF=BC=9A=20?= =?UTF-8?q?=20=20Makefile=20=09=E4=B8=BB=E6=96=87=E4=BB=B6=EF=BC=9A=20=20?= =?UTF-8?q?=20cproxy.c?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- Makefile | 14 ++ cproxy.c | 442 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 456 insertions(+) create mode 100644 Makefile create mode 100644 cproxy.c diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..72faa63 --- /dev/null +++ b/Makefile @@ -0,0 +1,14 @@ +CC = gcc +CFLAGS = -g -Wall -Werror + +all: cproxy + +cproxy: cproxy.o + $(CC) $(CFLAGS) cproxy.o -o cproxy + +cproxy.o: + $(CC) $(CFLAGS) -c cproxy.c + +clean: + rm -rf *.o + rm cproxy \ No newline at end of file diff --git a/cproxy.c b/cproxy.c new file mode 100644 index 0000000..c622c45 --- /dev/null +++ b/cproxy.c @@ -0,0 +1,442 @@ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define BUF_SIZE 8192 +#define PORT 9606 +#define MAX_HEADER_SIZE 8192 + +char remote_host[128]; +int remote_port; +int local_port; +int server_sock; +int client_sock; +int remote_sock; +char * header_buffer ; + +enum +{ + FLG_NONE = 0, // 正常数据流不进行编解码 + R_C_DEC = 1, // 读取客户端数据仅进行解码 + W_S_ENC = 2 // 发送到服务端进行编码 +}; + +static int io_flag; // 网络io的一些标志位 + +void handle_client(int client_sock, struct sockaddr_in client_addr); +void forward_header(int destination_sock); +void forward_data(int source_sock, int destination_sock); +void rewrite_header(); +int send_data(int socket,char * buffer,int len ); +int receive_data(int socket, char * buffer, int len); +void hand_mproxy_info_req(int sock,char * header_buffer) ; +int create_connection() ; +int _main(int argc, char *argv[]) ; + + +ssize_t readLine(int fd, void *buffer, size_t n) +{ + ssize_t numRead; + size_t totRead; + char *buf; + char ch; + + if (n <= 0 || buffer == NULL) { + errno = EINVAL; + return -1; + } + + buf = buffer; + + totRead = 0; + for (;;) { + numRead = receive_data(fd, &ch, 1); + + if (numRead == -1) { + if (errno == EINTR) + continue; + else + return -1; // 未知错误 + + } else if (numRead == 0) { // EOF + if (totRead == 0) // No bytes read; return 0 + return 0; + else // Some bytes read; add '\0' + break; + + } else { + + if (totRead < n - 1) { // Discard > (n - 1) bytes + totRead++; + *buf++ = ch; + } + + if (ch == '\n') + break; + } + } + + *buf = '\0'; + return totRead; +} + +int read_header(int fd, void * buffer) +{ + memset(header_buffer,0,MAX_HEADER_SIZE); + char line_buffer[2048]; + char * base_ptr = header_buffer; + + for(;;) + { + memset(line_buffer,0,2048); + + int total_read = readLine(fd,line_buffer,2048); + if(total_read <= 0) + { + return -1; + } + // 防止header缓冲区蛮越界 + if(base_ptr + total_read - header_buffer <= MAX_HEADER_SIZE) + { + strncpy(base_ptr,line_buffer,total_read); + base_ptr += total_read; + } else + { + return -1; + } + + // 读到了空行，http头结束 + if(strcmp(line_buffer,"\r\n") == 0 || strcmp(line_buffer,"\n") == 0) + { + break; + } + + } + return 0; + +} + +void extract_server_path(const char * header,char * output) +{ + char * p = strstr(header,"GET /"); + if(p) { + char * p1 = strchr(p+4,' '); + strncpy(output,p+4,(int)(p1 - p - 4) ); + } + +} + +int extract_host(const char * header) +{ + char * _p = strstr(header,"CONNECT"); // 在 CONNECT 方法中解析 隧道主机名称及端口号 + if(_p) + { + char * _p1 = strchr(_p,' '); + char * _p2 = strchr(_p1 + 1,':'); + char * _p3 = strchr(_p1 + 1,' '); + + if(_p2) + { + char s_port[10]; + bzero(s_port,10); + strncpy(remote_host,_p1+1,(int)(_p2 - _p1) - 1); + strncpy(s_port,_p2+1,(int) (_p3 - _p2) -1); + remote_port = atoi(s_port); + + } else + { + strncpy(remote_host,_p1+1,(int)(_p3 - _p1) -1); + remote_port = 80; + } + + + return 0; + } + + char * p = strstr(header,"Host:"); + if(!p) + { + return -1; + } + char * p1 = strchr(p,'\n'); + if(!p1) + { + return -1; + } + + char * p2 = strchr(p + 5,':'); // 5是指'Host:'的长度 + if(p2 && p2 < p1) + { + int p_len = (int)(p1 - p2 -1); + char s_port[p_len]; + strncpy(s_port,p2+1,p_len); + s_port[p_len] = '\0'; + remote_port = atoi(s_port); + + int h_len = (int)(p2 - p -5 -1 ); + strncpy(remote_host,p + 5 + 1 ,h_len); // Host: + remote_host[h_len] = '\0'; + } else + { + int h_len = (int)(p1 - p - 5 -1 -1); + strncpy(remote_host,p + 5 + 1,h_len); + remote_host[h_len] = '\0'; + remote_port = 80; + } + + return 0; +} + +// 响应隧道连接请求 +int send_tunnel_ok(int client_sock) +{ + char * resp = "HTTP/1.1 200 Connection Established\r\n\r\n"; + int len = strlen(resp); + char buffer[len+1]; + strcpy(buffer,resp); + if(send_data(client_sock,buffer,len) < 0) + { + return -1; + } + return 0; +} + +void hand_mproxy_info_req(int sock, char * header) { + char server_path[255] ; + char response[8192]; + extract_server_path(header,server_path); + + char info_buf[1024]; + sprintf(response,"HTTP/1.0 200 OK\nServer: CProxy/0.1\n\ + Content-type: text/html; charset=utf-8\n\n\ + \ + 
%s
\ + \n",info_buf); + + write(sock,response,strlen(response)); +} + +// 处理客户端的连接 +void handle_client(int client_sock, struct sockaddr_in client_addr) +{ + int is_http_tunnel = 0; + if(strlen(remote_host) == 0) // 未指定远端主机名称从http 请求 HOST 字段中获取 + { + if(read_header(client_sock,header_buffer) < 0) + { + return; + } else + { + char * p = strstr(header_buffer,"CONNECT"); // 判断是否是http 隧道请求 + if(p) + { + is_http_tunnel = 1; + } + + if(strstr(header_buffer,"GET /cproxy") > 0) + { + hand_mproxy_info_req(client_sock,header_buffer); + return; + } + + if(extract_host(header_buffer) < 0) + { + return; + } + } + } + + if ((remote_sock = create_connection()) < 0) { + return; + } + + if (fork() == 0) { // 创建子进程用于从客户端转发数据到远端socket接口 + + if(strlen(header_buffer) > 0 && !is_http_tunnel) + { + forward_header(remote_sock); //普通的http请求先转发header + } + + forward_data(client_sock, remote_sock); + exit(0); + } + + if (fork() == 0) { // 创建子进程用于转发从远端socket接口过来的数据到客户端 + + if(io_flag == W_S_ENC) + { + io_flag = R_C_DEC; // 发送请求给服务端进行编码，读取服务端的响应则进行解码 + } else if (io_flag == R_C_DEC) + { + io_flag = W_S_ENC; //接收客户端请求进行解码，那么响应客户端请求需要编码 + } + + if(is_http_tunnel) + { + send_tunnel_ok(client_sock); + } + + forward_data(remote_sock, client_sock); + exit(0); + } + + close(remote_sock); + close(client_sock); +} + +void forward_data(int source_sock, int destination_sock) { + char buffer[BUF_SIZE]; + int n; + + while ((n = receive_data(source_sock, buffer, BUF_SIZE)) > 0) + { + send_data(destination_sock, buffer, n); + } + + shutdown(destination_sock, SHUT_RDWR); + shutdown(source_sock, SHUT_RDWR); +} + +void forward_header(int destination_sock) +{ + rewrite_header(); + int len = strlen(header_buffer); + send_data(destination_sock,header_buffer,len) ; +} + +// 代理中的完整URL转发前需改成 path 的形式 +void rewrite_header() +{ + char * p = strstr(header_buffer,"http://"); + char * p0 = strchr(p,'\0'); + char * p5 = strstr(header_buffer,"HTTP/"); // "HTTP/" 是协议标识 如 "HTTP/1.1" + int len = strlen(header_buffer); + if(p) + { + char * p1 = strchr(p + 7,'/'); + if(p1 && (p5 > p1)) + { + // 转换url到 path + memcpy(p,p1,(int)(p0 -p1)); + int l = len - (p1 - p) ; + header_buffer[l] = '\0'; + } else + { + char * p2 = strchr(p,' '); // GET http://3g.sina.com.cn HTTP/1.1 + memcpy(p + 1,p2,(int)(p0-p2)); + *p = '/'; // url 没有路径使用根 + int l = len - (p2 - p ) + 1; + header_buffer[l] = '\0'; + + } + } +} + +int receive_data(int socket, char * buffer, int len) +{ + int n = recv(socket, buffer, len, 0); + if(io_flag == R_C_DEC && n > 0) + { + int i; + for(i = 0; i< n; i++ ) + { + buffer[i] ^= 1; + } + } + + return n; +} + +int send_data(int socket,char * buffer,int len) +{ + if(io_flag == W_S_ENC) + { + int i; + for(i = 0; i < len ; i++) + { + buffer[i] ^= 1; + } + } + return send(socket,buffer,len,0); +} + +int create_connection() { + struct sockaddr_in server_addr; + struct hostent *server; + int sock; + + if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) { + return -1; + } + + if ((server = gethostbyname(remote_host)) == NULL) { + errno = EFAULT; + return -1; + } + + memset(&server_addr, 0, sizeof(server_addr)); + server_addr.sin_family = AF_INET; + memcpy(&server_addr.sin_addr.s_addr, server->h_addr, server->h_length); + server_addr.sin_port = htons(remote_port); + + if (connect(sock, (struct sockaddr *) &server_addr, sizeof(server_addr)) < 0) { + return -1; + } + + return sock; +} + +int _main(int argc, char *argv[]) +{ + header_buffer = (char *) malloc(MAX_HEADER_SIZE); + + int server_sock, optval; + struct sockaddr_in server_addr; + if ((server_sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) { + return -1; + } + if (setsockopt(server_sock, SOL_SOCKET, SO_REUSEADDR, &optval, sizeof(optval)) < 0) { + return -1; + } + memset(&server_addr, 0, sizeof(server_addr)); + server_addr.sin_family = AF_INET; + server_addr.sin_port = htons(PORT); + server_addr.sin_addr.s_addr = INADDR_ANY; + if (bind(server_sock, (struct sockaddr*)&server_addr, sizeof(server_addr)) != 0) { + return -1; + } + if (listen(server_sock, 17) < 0) { + return -1; + } + + struct sockaddr_in clnt_addr; + socklen_t clnt_addr_size = sizeof(clnt_addr); + while (1) { + int client_socket = + accept(server_sock, (struct sockaddr *) &clnt_addr, + &clnt_addr_size); + + if (fork() == 0) { // 创建子进程处理客户端连接请求 + close(server_sock); + handle_client(client_socket, clnt_addr); + printf("%s", header_buffer); + exit(0); + } + close(client_socket); + } +} + +int main(int argc, char *argv[]) +{ + return _main(argc,argv); +}