C语言实现的websocket

#include <stdlib.h> #include <stdio.h> #include <string.h> #include <unistd.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> /*在握手时需要进行sha1编码和base64编码， 在这里用openssl的库来实现*/ #if 0 #include <openssl/sha.h> #include <openssl/pem.h> #include <openssl/bio.h> #include "openssl/evp.h" #else #include "openssl/sha.h" #include "openssl/pem.h" #include "openssl/bio.h" #include "openssl/evp.h" #endif //#include "base64.h" #define BUFFER_SIZE 1024 #define RESPONSE_HEADER_LEN_MAX 1024 #define GUID "258EAFA5-E914-47DA-95CA-C5AB0DC85B11" typedef struct _frame_head { char fin; char opcode; char mask; unsigned long long payload_length; char masking_key[4]; } frame_head; int passive_server(int port,int queue) { ///定义sockfd int server_sockfd = socket(AF_INET,SOCK_STREAM, 0); ///定义sockaddr_in struct sockaddr_in server_sockaddr; server_sockaddr.sin_family = AF_INET; server_sockaddr.sin_port = htons(port); server_sockaddr.sin_addr.s_addr = htonl(INADDR_ANY); int reuse = 0; setsockopt(server_sockfd, SOL_SOCKET, SO_REUSEADDR, (char *)&reuse, sizeof(int)); ///bind，成功返回0，出错返回-1 if(bind(server_sockfd,(struct sockaddr *)&server_sockaddr,sizeof(server_sockaddr))==-1) { perror("bind"); exit(1); } ///listen，成功返回0，出错返回-1 if(listen(server_sockfd,queue) == -1) { perror("listen"); exit(1); } printf("监听%d端口\n",port); return server_sockfd; } unsigned char *base64_encode(unsigned char *str) { long len; long str_len; unsigned char *res; int i,j; //定义base64编码表 unsigned char *base64_table="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; //计算经过base64编码后的字符串长度 str_len=SHA_DIGEST_LENGTH;//str_len=strlen(str); if(str_len % 3 == 0) len=str_len/3*4; else len=(str_len/3+1)*4; res=malloc(sizeof(unsigned char)*len+1); res[len]='\0'; //以3个8位字符为一组进行编码 for(i=0,j=0;i<len-2;j+=3,i+=4) { res[i]=base64_table[str[j]>>2]; //取出第一个字符的前6位并找出对应的结果字符 res[i+1]=base64_table[(str[j]&0x3)<<4 | (str[j+1]>>4)]; //将第一个字符的后位与第二个字符的前4位进行组合并找到对应的结果字符 res[i+2]=base64_table[(str[j+1]&0xf)<<2 | (str[j+2]>>6)]; //将第二个字符的后4位与第三个字符的前2位组合并找出对应的结果字符 res[i+3]=base64_table[str[j+2]&0x3f]; //取出第三个字符的后6位并找出结果字符 } switch(str_len % 3) { case 1: res[i-2]='='; res[i-1]='='; break; case 2: res[i-1]='='; break; } return res; } int _readline(char* allbuf,int level,char* linebuf) { int len = strlen(allbuf); for (;level<len;++level) { if(allbuf[level]=='\r' && allbuf[level+1]=='\n') return level+2; else *(linebuf++) = allbuf[level]; } return -1; } int shakehands(int cli_fd) { //next line's point num int level = 0; //all request data char buffer[BUFFER_SIZE]; //a line data char linebuf[256]; //Sec-WebSocket-Accept char sec_accept[32]; //sha1 data unsigned char sha1_data[SHA_DIGEST_LENGTH+1]={0}; //reponse head buffer char head[BUFFER_SIZE] = {0}; if (read(cli_fd,buffer,sizeof(buffer))<=0) perror("read"); printf("request\n"); printf("%s\n",buffer); do { memset(linebuf,0,sizeof(linebuf)); level = _readline(buffer,level,linebuf); //printf("line:%s\n",linebuf); if (strstr(linebuf,"Sec-WebSocket-Key")!=NULL) { strcat(linebuf,GUID); // printf("key:%s\nlen=%d\n",linebuf+19,strlen(linebuf+19)); SHA1((unsigned char*)&linebuf+19,strlen(linebuf+19),(unsigned char*)&sha1_data); // printf("sha1:%s\n",sha1_data); //base64_encode(sha1_data,strlen(sha1_data),sec_accept); //sec_accept = base64_encode(sha1_data); // printf("base64:%s\n",sec_accept); /* write the response */ sprintf(head, "HTTP/1.1 101 Switching Protocols\r\n" \ "Upgrade: websocket\r\n" \ "Connection: Upgrade\r\n" \ "Sec-WebSocket-Accept: %s\r\n" \ "\r\n",base64_encode(sha1_data)); printf("response\n"); printf("%s",head); if (write(cli_fd,head,strlen(head))<0) perror("write"); break; } }while((buffer[level]!='\r' || buffer[level+1]!='\n') && level!=-1); return 0; } void inverted_string(char *str,int len) { int i; char temp; for (i=0;i<len/2;++i) { temp = *(str+i); *(str+i) = *(str+len-i-1); *(str+len-i-1) = temp; } } int recv_frame_head(int fd,frame_head* head) { char one_char; /*read fin and op code*/ if (read(fd,&one_char,1)<=0) { perror("read fin"); return -1; } head->fin = (one_char & 0x80) == 0x80; head->opcode = one_char & 0x0F; if (read(fd,&one_char,1)<=0) { perror("read mask"); return -1; } head->mask = (one_char & 0x80) == 0X80; /*get payload length*/ head->payload_length = one_char & 0x7F; if (head->payload_length == 126) { char extern_len[2]; if (read(fd,extern_len,2)<=0) { perror("read extern_len"); return -1; } head->payload_length = (extern_len[0]&0xFF) << 8 | (extern_len[1]&0xFF); } else if (head->payload_length == 127) { char extern_len[8]; if (read(fd,extern_len,8)<=0) { perror("read extern_len"); return -1; } inverted_string(extern_len,8); memcpy(&(head->payload_length),extern_len,8); } /*read masking-key*/ if (read(fd,head->masking_key,4)<=0) { perror("read masking-key"); return -1; } return 0; } void umask(char *data,int len,char *mask) { int i; for (i=0;i<len;++i) *(data+i) ^= *(mask+(i%4)); } int send_frame_head(int fd,frame_head* head) { char *response_head; int head_length = 0; if(head->payload_length<126) { response_head = (char*)malloc(2); response_head[0] = 0x81; response_head[1] = head->payload_length; head_length = 2; } else if (head->payload_length<0xFFFF) { response_head = (char*)malloc(4); response_head[0] = 0x81; response_head[1] = 126; response_head[2] = (head->payload_length >> 8 & 0xFF); response_head[3] = (head->payload_length & 0xFF); head_length = 4; } else { response_head = (char*)malloc(12); response_head[0] = 0x81; response_head[1] = 127; memcpy(response_head+2,&head->payload_length,sizeof(unsigned long long)); inverted_string(response_head+2,sizeof(unsigned long long)); head_length = 12; } if(write(fd,response_head,head_length)<=0) { perror("write head"); return -1; } free(response_head); return 0; } int main() { int ser_fd = passive_server(4444,20); struct sockaddr_in client_addr; socklen_t addr_length = sizeof(client_addr); int conn = accept(ser_fd,(struct sockaddr*)&client_addr, &addr_length); shakehands(conn); while (1) { frame_head head; int rul = recv_frame_head(conn,&head); if (rul < 0) break; // printf("fin=%d\nopcode=0x%X