1.本段代码采用了 select I/O端口复用
2.含有三种功能：ls, 上传文件， 下载文件。这是拷贝别人的代码，自己添加了注释，随后会进行修改，
自己需要的功能：上传文件， 下载文件， （并且在传输途中，对所有的文件进行openssl加密）
1 #include <stdio.h> 2 #include <stdlib.h> 3 #include <netdb.h> 4 #include <errno.h> 5 #include <sys/types.h> 6 #include <sys/stat.h> 7 #include <fcntl.h> 8 #include <unistd.h> 9 #include <string.h> 10 #include <sys/ioctl.h> 11 #include <sys/fcntl.h> 12 13 14 #define MAXBUF 1024 //宏大小 15 #define STDIN_FILENO 1 //标准输入 16 #define STDOUT_FILENO 0 //标准输出 17 18 19 #define USERNAME 220 //用户名 20 #define PASSWORD 331 //密码 21 #define LOGIN 230 //登录 22 #define PATHNAME 257 //路径名 23 #define CLOSEDATA 226 // 24 #define ACTIONOK 250 // 25 26 27 char *rbuf,*rbuf1,*wbuf,*wbuf1; 28 29 30 char filename[100]; //文件名 31 char *host; //要连接的服务器地址 32 33 34 struct sockaddr_in servaddr; //服务器的地址、端口结构体 35 36 //1.第一步，打开一个TCP链接 37 int cliopen(char *host,int port); 38 // 39 int strtosrv(char *str); 40 int ftp_get(int sck,char *pDownloadFileName); 41 int ftp_put(int sck,char *pUploadFileName_s); 42 void cmd_tcp(int sockfd); // 43 44 //主函数 45 int main(int argc,char *argv[]) 46 { 47 int fd; 48 49 //判断输入参数 50 if(0 != argc -2) 51 { 52 printf("%s ","missing <hostname>"); 53 exit(0); 54 } 55 56 //指定服务器地址 57 host = argv[1]; 58 //指定端口 59 int port = 21; 60 61 rbuf = (char *)malloc(MAXBUF*sizeof(char)); 62 rbuf1 = (char *)malloc(MAXBUF*sizeof(char)); 63 wbuf = (char *)malloc(MAXBUF*sizeof(char)); 64 wbuf1 = (char *)malloc(MAXBUF*sizeof(char)); 65 66 //1.得到已连接的套接字 67 fd = cliopen(host,port); 68 69 //2. 70 cmd_tcp(fd); 71 72 exit(0); 73 } 74 75 76 77 78 //1.第一步，打开一个TCP链接 79 int cliopen(char *host,int port) 80 { 81 int control_sock; 82 83 //1.FTP 自己的传输地址结构体 84 struct hostent *ht = NULL; 85 86 //2.创建套接字 87 control_sock = socket(AF_INET,SOCK_STREAM,0); 88 if(control_sock < 0) 89 { 90 printf("socket error "); 91 return -1; 92 } 93 94 //3.将IP地址进行转换，变为FTP地址结构体 95 ht = gethostbyname(host); 96 if(!ht) 97 { 98 return -1; 99 } 100 101 //4.连接服务器，返回套接字 102 memset(&servaddr,0,sizeof(struct sockaddr_in)); 103 memcpy(&servaddr.sin_addr.s_addr,ht->h_addr,ht->h_length); 104 servaddr.sin_family = AF_INET; 105 servaddr.sin_port = htons(port); 106 107 if(connect(control_sock,(struct sockaddr*)&servaddr,sizeof(struct sockaddr)) == -1) 108 { 109 return -1; 110 } 111 return control_sock; 112 } 113 114 //匹配下载的文件名 115 int s(char *str,char *s2) 116 { 117 //char s1[100]; 118 119 return sscanf(str," get %s",s2) == 1; 120 121 } 122 123 //匹配上传的文件名 124 int st(char *str,char *s1) 125 { 126 return sscanf(str," put %s",s1) == 1; 127 } 128 129 //获取服务器 发送给 客户端的 IP地址 和 端口; 130 int strtosrv(char *str) 131 { 132 int addr[6]; 133 //printf("%s ",str); 134 sscanf(str,"%*[^(](%d,%d,%d,%d,%d,%d)",&addr[0],&addr[1],&addr[2],&addr[3],&addr[4],&addr[5]); 135 bzero(host,strlen(host)); 136 sprintf(host,"%d.%d.%d.%d",addr[0],addr[1],addr[2],addr[3]); 137 int port = addr[4]*256 + addr[5]; 138 return port; 139 } 140 141 //显示文件列表 142 void ftp_list(int sockfd) 143 { 144 int nread; 145 for(;;) 146 { 147 if((nread = recv(sockfd,rbuf1,MAXBUF,0)) < 0) 148 { 149 printf("recv error "); 150 } 151 else if(nread == 0) 152 { 153 //printf("over "); 154 break; 155 } 156 if(write(STDOUT_FILENO,rbuf1,nread) != nread) 157 printf("send error to stdout "); 158 /*else 159 printf("read something ");*/ 160 } 161 if(close(sockfd) < 0) 162 printf("close error "); 163 } 164 165 //下载文件 166 int ftp_get(int sck,char *pDownloadFileName) 167 { 168 int handle = open(pDownloadFileName,O_WRONLY | O_CREAT | O_TRUNC, S_IREAD| S_IWRITE); 169 int nread; 170 printf("%d ",handle); 171 /*if(handle == -1) 172 return -1;*/ 173 174 //2. 猜测 ====================应该是将 ssl 接口放在这里，用来传输数据 175 176 for(;;) 177 { 178 if((nread = recv(sck,rbuf1,MAXBUF,0)) < 0) 179 { 180 printf("receive error "); 181 } 182 else if(nread == 0) 183 { 184 printf("over "); 185 break; 186 } 187 // printf("%s ",rbuf1); 188 if(write(handle,rbuf1,nread) != nread) 189 printf("receive error from server!"); 190 if(write(STDOUT_FILENO,rbuf1,nread) != nread) 191 printf("receive error from server!"); 192 } 193 if(close(sck) < 0) 194 printf("close error "); 195 } 196 197 198 //上传文件 199 int ftp_put(int sck,char *pUploadFileName_s) 200 { 201 //int c_sock; 202 int handle = open(pUploadFileName_s,O_RDWR); 203 int nread; 204 if(handle == -1) 205 return -1; 206 //ftp_type(c_sock,"I"); 207 208 //3. 猜测 ====================应该是将 ssl 接口放在这里，用来传输数据 209 for(;;) 210 { 211 if((nread = read(handle,rbuf1,MAXBUF)) < 0) 212 { 213 printf("read error!"); 214 } 215 else if(nread == 0) 216 break; 217 if(write(STDOUT_FILENO,rbuf1,nread) != nread) 218 printf("send error!"); 219 if(write(sck,rbuf1,nread) != nread) 220 printf("send error!"); 221 } 222 if(close(sck) < 0) 223 printf("close error "); 224 } 225 226 227 228 //各种参数的执行 229 void cmd_tcp(int sockfd) 230 { 231 int maxfdp1,nread,nwrite,fd,replycode,tag=0,data_sock; 232 int port; 233 char *pathname; 234 fd_set rset; //可读文件描述符集合 235 FD_ZERO(&rset); //清空可读文件描述符集合 236 maxfdp1 = sockfd + 1; //最大套接字 237 238 for(;;) 239 { 240 //1.将 标准输入加入 可读文件描述符集合 241 FD_SET(STDIN_FILENO,&rset); 242 //2.将 命令套接字 加入可读文件描述符集合 243 FD_SET(sockfd,&rset); 244 245 //3.监听读事件 246 if(select(maxfdp1,&rset,NULL,NULL,NULL)<0) 247 { 248 printf("select error "); 249 } 250 //4.判断标准输入是否有读事件 251 if(FD_ISSET(STDIN_FILENO,&rset)) 252 { 253 //5.清空读缓冲区 和 写缓冲区 254 bzero(wbuf,MAXBUF); //zero 255 bzero(rbuf1,MAXBUF); 256 257 if((nread = read(STDIN_FILENO,rbuf1,MAXBUF)) <0) 258 printf("read error from stdin "); 259 nwrite = nread + 5; 260 261 //=======这里不懂，replycode 什么时候赋的值 262 263 //6.命令套接字中 写入 用户名 264 if(replycode == USERNAME) 265 { 266 sprintf(wbuf,"USER %s",rbuf1); 267 268 if(write(sockfd,wbuf,nwrite) != nwrite) 269 { 270 printf("write error "); 271 } 272 //printf("%s ",wbuf); 273 //memset(rbuf1,0,sizeof(rbuf1)); 274 //memset(wbuf,0,sizeof(wbuf)); 275 //printf("1:%s ",wbuf); 276 } 277 278 //7.命令套接字中 写入 密码 279 if(replycode == PASSWORD) 280 { 281 //printf("%s ",rbuf1); 282 sprintf(wbuf,"PASS %s",rbuf1); 283 if(write(sockfd,wbuf,nwrite) != nwrite) 284 printf("write error "); 285 //bzero(rbuf,sizeof(rbuf)); 286 //printf("%s ",wbuf); 287 //printf("2:%s ",wbuf); 288 } 289 290 if(replycode == 550 || replycode == LOGIN || replycode == CLOSEDATA || replycode == PATHNAME || replycode == ACTIONOK) 291 { 292 if(strncmp(rbuf1,"pwd",3) == 0) 293 { 294 //printf("%s ",rbuf1); 295 sprintf(wbuf,"%s","PWD "); 296 write(sockfd,wbuf,4); 297 continue; 298 } 299 if(strncmp(rbuf1,"quit",4) == 0) 300 { 301 sprintf(wbuf,"%s","QUIT "); 302 write(sockfd,wbuf,5); 303 //close(sockfd); 304 if(close(sockfd) <0) 305 printf("close error "); 306 break; 307 } 308 if(strncmp(rbuf1,"cwd",3) == 0) 309 { 310 //sprintf(wbuf,"%s","PASV "); 311 sprintf(wbuf,"%s",rbuf1); 312 write(sockfd,wbuf,nread); 313 314 //sprintf(wbuf1,"%s","CWD "); 315 316 continue; 317 } 318 319 if(strncmp(rbuf1,"ls",2) == 0) 320 { 321 tag = 2; //显示文件 标识符 322 //printf("%s ",rbuf1); 323 sprintf(wbuf,"%s","PASV "); 324 //printf("%s ",wbuf); 325 write(sockfd,wbuf,5); 326 //read 327 //sprintf(wbuf1,"%s","LIST -al "); 328 nwrite = 0; 329 //write(sockfd,wbuf1,nwrite); 330 //ftp_list(sockfd); 331 continue; 332 } 333 //8.下载文件 334 if(strncmp(rbuf1,"get",3) == 0) 335 { 336 tag = 1; //下载文件标识符 337 338 //被动传输模式 339 sprintf(wbuf,"%s","PASV "); 340 //printf("%s ",s(rbuf1)); 341 //char filename[100]; 342 s(rbuf1,filename); 343 printf("%s ",filename); 344 write(sockfd,wbuf,5); 345 continue; 346 } 347 348 if(strncmp(rbuf1,"put",3) == 0) 349 { 350 tag = 3; //上传文件标识符 351 sprintf(wbuf,"%s","PASV "); 352 353 //把内容赋值给 读缓冲区 354 st(rbuf1,filename); 355 printf("%s ",filename); 356 write(sockfd,wbuf,5); 357 continue; 358 } 359 } 360 /*if(close(sockfd) <0) 361 printf("close error ");*/ 362 } 363 if(FD_ISSET(sockfd,&rset)) 364 { 365 //9.清空读缓冲区 和 写缓冲区 366 bzero(rbuf,strlen(rbuf)); 367 //10.读套接字中的内容 368 if((nread = recv(sockfd,rbuf,MAXBUF,0)) <0) 369 printf("recv error "); 370 else if(nread == 0) 371 break; 372 373 //比较 374 if(strncmp(rbuf,"220",3) ==0 || strncmp(rbuf,"530",3)==0) 375 { 376 /*if(write(STDOUT_FILENO,rbuf,nread) != nread) 377 printf("write error to stdout ");*/ 378 379 //链接字符串 380 strcat(rbuf,"your name:"); 381 382 //printf("%s ",rbuf); 383 nread += 12; 384 /*if(write(STDOUT_FILENO,rbuf,nread) != nread) 385 printf("write error to stdout ");*/ 386 replycode = USERNAME; 387 } 388 if(strncmp(rbuf,"331",3) == 0) 389 { 390 /*if(write(STDOUT_FILENO,rbuf,nread) != nread) 391 printf("write error to stdout ")*/; 392 strcat(rbuf,"your password:"); 393 nread += 16; 394 /*if(write(STDOUT_FILENO,rbuf,nread) != nread) 395 printf("write error to stdout ");*/ 396 replycode = PASSWORD; 397 } 398 if(strncmp(rbuf,"230",3) == 0) 399 { 400 /*if(write(STDOUT_FILENO,rbuf,nread) != nread) 401 printf("write error to stdout ");*/ 402 replycode = LOGIN; 403 } 404 if(strncmp(rbuf,"257",3) == 0) 405 { 406 /*if(write(STDOUT_FILENO,rbuf,nread) != nread) 407 printf("write error to stdout ");*/ 408 replycode = PATHNAME; 409 } 410 if(strncmp(rbuf,"226",3) == 0) 411 { 412 /*if(write(STDOUT_FILENO,rbuf,nread) != nread) 413 printf("write error to stdout ");*/ 414 replycode = CLOSEDATA; 415 } 416 if(strncmp(rbuf,"250",3) == 0) 417 { 418 /*if(write(STDOUT_FILENO,rbuf,nread) != nread) 419 printf("write error to stdout ");*/ 420 replycode = ACTIONOK; 421 } 422 if(strncmp(rbuf,"550",3) == 0) 423 { 424 replycode = 550; 425 } 426 /*if(strncmp(rbuf,"150",3) == 0) 427 { 428 if(write(STDOUT_FILENO,rbuf,nread) != nread) 429 printf("write error to stdout "); 430 }*/ 431 //fprintf(stderr,"%d ",1); 432 if(strncmp(rbuf,"227",3) == 0) 433 { 434 //printf("%d ",1); 435 /*if(write(STDOUT_FILENO,rbuf,nread) != nread) 436 printf("write error to stdout ");*/ 437 438 //获取服务器返回的 接收数据的端口，和地址 439 int port1 = strtosrv(rbuf); 440 printf("%d ",port1); 441 printf("%s ",host); 442 443 //创建新的传输数据的套接字? 444 //1. 猜测 ====================应该是将 ssl 接口放在这里，用来传输数据 445 data_sock = cliopen(host,port1); 446 447 448 449 //bzero(rbuf,sizeof(rbuf)); 450 //printf("%d ",fd); 451 //if(strncmp(rbuf1,"ls",2) == 0) 452 if(tag == 2) 453 { 454 write(sockfd,"list ",strlen("list ")); 455 ftp_list(data_sock); 456 /*if(write(STDOUT_FILENO,rbuf,nread) != nread) 457 printf("write error to stdout ");*/ 458 459 } 460 //else if(strncmp(rbuf1,"get",3) == 0) 461 else if(tag == 1) 462 { 463 //sprintf(wbuf,"%s","RETR "); 464 //printf("%s ",wbuf); 465 //int str = strlen(filename); 466 //printf("%d ",str); 467 sprintf(wbuf,"RETR %s ",filename); 468 printf("%s ",wbuf); 469 //int p = 5 + str + 1; 470 471 //命令套接字中写入 下载文件命令 472 printf("%d ",write(sockfd,wbuf,strlen(wbuf))); 473 //printf("%d ",p); 474 475 //下载文件 476 ftp_get(data_sock,filename); 477 } 478 else if(tag == 3) 479 { 480 481 // 上传文件 482 sprintf(wbuf,"STOR %s ",filename); 483 printf("%s ",wbuf); 484 write(sockfd,wbuf,strlen(wbuf)); 485 ftp_put(data_sock,filename); 486 } 487 nwrite = 0; 488 } 489 /*if(strncmp(rbuf,"150",3) == 0) 490 { 491 if(write(STDOUT_FILENO,rbuf,nread) != nread) 492 printf("write error to stdout "); 493 }*/ 494 //printf("%s ",rbuf); 495 if(write(STDOUT_FILENO,rbuf,nread) != nread) 496 printf("write error to stdout "); 497 /*else 498 printf("%d ",-1);*/ 499 } 500 } 501 }