server/src/parse_cmd.c

   1 /*
   2  * Copyright (c) 2007,西安邮电学院Linux兴趣小组
   3  * All rights reserved.
   4  *
   5  * 文件名称：parse_cmd.c
   6  * 摘    要：从一行数据中解析出命令和参数 并调用相应的命令处理模块
   7  * 对读取的字符串做了初步分析 提高了容错能力 对参数的接收做了限制，一次只接收一个参数。
   8  * 重写了接收参数模块,去掉了无用参数buf_size,_line_cmd()的返回值改成了结构体指针。
   9  * 当前版本：4.0
  10  * 作    者：贾孟树
  11  * 完成日期：2007年6月13日
  12  * 取代版本：3.0
  13  * 完成日期：2007年6月8日
  14  * 修改者：王聪
  15  * 修改日期：2007年6月15日
  16  */
  17
  18
  19 #include "xylftp.h"
  20 #include "do_cmd.h"
  21 #include "debug.h"
  22
  23 #define MAX_CMD 5
  24 #define MAX_ARG 4096
  25
  26 extern struct user_env user_env;
  27 extern struct run_env run_env;
  28 struct parse_cmd{
  29         char cmd[MAX_CMD];
  30         char arg[MAX_ARG];
  31 };
  32
  33
  34 const char *commands[] = {"USER","PASS","SYST","QUIT","RETR","STOR","RNFR","RNTO","ABOR","DELE",
  35                 "RMD","MKD","PWD","CWD","CDUP","PORT","NOOP","PASV","TYPE","MODE",
  36                 "STAT","STRU","LIST"};                  /*服务器支持的所有命令*/
  37
  38 static int _line_cmd(char *line_buf, struct parse_cmd *user_cmd)
  39 {
  40         int     i = 0;
  41         int     j = 0;
  42         int     k = 0;
  43
  44         while (!isalpha(line_buf[i])) {
  45                 i++;
  46         }               /*<--略过不是字母的字符*/
  47         while (line_buf[i] != ' '
  48                         && line_buf[i] != '\r'
  49                         && line_buf[i] != '\n') {
  50                 if (k < MAX_CMD-1) {
  51                         user_cmd->cmd[k++] = line_buf[i];
  52                         i++;
  53                 }
  54                 else {
  55                         return -1;
  56                 }
  57         }               /*<--接收以字母开头的字符串（命令）*/
  58         while (line_buf[i] == ' ') {
  59                 i++;
  60         }               /*<--清除命令与参数之间的空格*/
  61         while (line_buf[i] != '\0'
  62                         && line_buf[i] != '\r'
  63                         && line_buf[i] != '\n') {
  64                 user_cmd->arg[j++] = line_buf[i];
  65                 i++;
  66         }               /*<--只提取第一个参数*/
  67
  68         for (;k >= 0;k--) {             /*检查命令中字母的大小写，若是小写字母，则转化为大写字母*/
  69                 user_cmd->cmd[k] = toupper(user_cmd->cmd[k]);
  70         }
  71 #ifdef DEBUG
  72         printf("\n");
  73         printf("CMD:");
  74         printf("%s",user_cmd->cmd);
  75         printf("\n");
  76         printf("ARG:");
  77         printf("%s",user_cmd->arg);
  78         printf("\n");
  79 #endif
  80         return 0;
  81 }
  82
  83 static int _cmd_num(struct parse_cmd cmd)
  84 {
  85         int i;
  86         for (i = 0; i < (int)(sizeof(commands)/sizeof(commands[0])); i++) {
  87                 if (strcmp(cmd.cmd, commands[i]) == 0) {
  88                         return i+1;
  89                 }
  90         }
  91         return 0;
  92 }
  93
  94
  95 int parse_cmd(char *p_buf)
  96 {
  97         char rnfr_arg[MAX_ARG];
  98         struct parse_cmd user_cmd;
  99         const char login_error[] = "530 Please login with USER and PASS.\r\n";
 100         int i = 0;
 101
 102         memset(&user_cmd, 0, sizeof(struct parse_cmd));
 103         if (_line_cmd(p_buf, &user_cmd) == -1) {
 104                 failed(user_cmd.cmd);
 105                 return 2;
 106         }
 107         if (( i = _cmd_num(user_cmd)) <= 4 || user_env.login_in == TRUE) {
 108                 switch (i) {
 109                 case 1:
 110 #ifdef DEBUG
 111                                 printf("****call user()\n");
 112 #endif
 113                                 do_user(user_cmd.arg);
 114                                 break;
 115                 case 2:
 116 #ifdef DEBUG
 117                                 printf("call pass()\n");
 118                                 printf("username=%s\n", user_env.user_name);
 119 #endif
 120                                 if (strlen(user_env.user_name) != 0) {
 121                                         if (do_pass(user_cmd.arg) == 0) {
 122                                                 if (chroot(run_env.ftp_dir) < 0) {
 123                                                         write_log("chroot error", 0);
 124                                                         do_quit();
 125                                                         break;
 126                                                 }
 127                                                 if (chdir("/") < 0) {
 128                                                         write_log("chdir error", 0);
 129                                                         do_quit();
 130                                                         break;
 131                                                 }
 132                                         } else {
 133                                                 break;
 134                                         }
 135                                 } else {
 136                                         const char mess[] = "220 No username input.\r\n";
 137                                         write(user_env.connect_fd, mess, strlen(mess));
 138                                 }
 139
 140                                 break;
 141                 case 3:
 142                                 debug_printf("call syst()\n");
 143                                 do_syst();
 144                                 break;
 145                 case 4:
 146                                 debug_printf("call quit()\n");
 147                                 do_quit();
 148                                 break;
 149                 case 5:
 150                                 debug_printf("call retr()\n");
 151                                 do_retr(user_cmd.arg);
 152                                 break;
 153                 case 6:
 154                                 debug_printf("call stor()\n");
 155                                 do_stor(user_cmd.arg);
 156                                 break;
 157                 case 7:
 158                                 debug_printf("call rnfr()\n");
 159                                 do_rnfr();
 160                                 strcpy(rnfr_arg, user_cmd.arg);
 161                                 break;
 162                 case 8:
 163                                 debug_printf("call rnto()\n");
 164                                 do_rnto(rnfr_arg, user_cmd.arg);
 165                                 memset(rnfr_arg, 0, MAX_ARG);
 166                                 break;
 167                 case 9:
 168                                 debug_printf("call abor()\n");
 169                                 fflush(stdout);
 170                                 do_abor(user_cmd.arg);
 171                                 break;
 172                 case 10:
 173                                 debug_printf("call dele()\n");
 174                                 do_dele(user_cmd.arg);
 175                                 break;
 176                 case 11:
 177                                 debug_printf("call rmd()\n");
 178                                 do_rmd(user_cmd.arg);
 179                                 break;
 180                 case 12:
 181                                 debug_printf("call mkd()\n");
 182                                 do_mkd(user_cmd.arg);
 183                                 break;
 184                 case 13:
 185                                 debug_printf("call pwd()\n");
 186                                 do_pwd();
 187                                 break;
 188                 case 14:
 189                                 debug_printf("call cwd()\n");
 190                                 do_cwd(user_cmd.arg);
 191                                 break;
 192                 case 15:
 193                                 debug_printf("call cdup()\n");
 194                                 do_cdup();
 195                                 break;
 196                 case 16:
 197                                 debug_printf("call port()\n");
 198                                 do_port(user_cmd.arg);
 199                                 break;
 200                 case 17:
 201                                 debug_printf("call noop()\n");
 202                                 do_noop();
 203                                 break;
 204                 case 18:
 205                                 debug_printf("call pasv()\n\n");
 206                                 do_pasv();
 207                                 break;
 208                 case 19:
 209                                 debug_printf("call type()\n");
 210                                 do_type(user_cmd.arg);
 211                                 break;
 212                 case 20:
 213                                 debug_printf("call mode()\n");
 214                                 do_mode(user_cmd.arg);
 215                                 break;
 216                 case 21:
 217                                 debug_printf("call stat()\n");
 218                                 do_stat(user_cmd.arg);
 219                                 break;
 220                 case 22:
 221                                 debug_printf("call stru()\n");
 222                                 do_stru(user_cmd.arg);
 223                                 break;
 224                 case 23:
 225                                 debug_printf("call list()\n");
 226                                 do_list(user_cmd.arg);
 227                                 break;
 228                 default:
 229                                 debug_printf("call failed()\n");
 230                                 failed(user_cmd.cmd);
 231                                 break;
 232                 }
 233         } else if (i <= 23 && i >= 1) {
 234                 write(user_env.connect_fd, login_error, strlen(login_error));
 235         } else {
 236                 failed(user_cmd.cmd);
 237         }
 238         return 1;
 239 }