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                                 debug_printf("****call user()\n");
 111                                 do_user(user_cmd.arg);
 112                                 break;
 113                 case 2:
 114                                 debug_printf("call pass()\n");
 115                                 printf("username=%s\n", user_env.user_name);
 116
 117                                 if (strlen(user_env.user_name) != 0) {
 118                                         if (do_pass(user_cmd.arg) == 0) {
 119                                                 if (chroot(run_env.ftp_dir) < 0) {
 120                                                         write_log("chroot error", 0);
 121                                                         do_quit();
 122                                                         break;
 123                                                 }
 124                                                 if (chdir("/") < 0) {
 125                                                         write_log("chdir error", 0);
 126                                                         do_quit();
 127                                                         break;
 128                                                 }
 129                                         } else {
 130                                                 break;
 131                                         }
 132                                 } else {
 133                                         const char mess[] = "220 No username input.\r\n";
 134                                         write(user_env.connect_fd, mess, strlen(mess));
 135                                 }
 136
 137                                 break;
 138                 case 3:
 139                                 debug_printf("call syst()\n");
 140                                 do_syst();
 141                                 break;
 142                 case 4:
 143                                 debug_printf("call quit()\n");
 144                                 do_quit();
 145                                 break;
 146                 case 5:
 147                                 debug_printf("call retr()\n");
 148                                 do_retr(user_cmd.arg);
 149                                 break;
 150                 case 6:
 151                                 debug_printf("call stor()\n");
 152                                 do_stor(user_cmd.arg);
 153                                 break;
 154                 case 7:
 155                                 debug_printf("call rnfr()\n");
 156                                 do_rnfr();
 157                                 strcpy(rnfr_arg, user_cmd.arg);
 158                                 break;
 159                 case 8:
 160                                 debug_printf("call rnto()\n");
 161                                 do_rnto(rnfr_arg, user_cmd.arg);
 162                                 memset(rnfr_arg, 0, MAX_ARG);
 163                                 break;
 164                 case 9:
 165                                 debug_printf("call abor()\n");
 166                                 fflush(stdout);
 167                                 do_abor(user_cmd.arg);
 168                                 break;
 169                 case 10:
 170                                 debug_printf("call dele()\n");
 171                                 do_dele(user_cmd.arg);
 172                                 break;
 173                 case 11:
 174                                 debug_printf("call rmd()\n");
 175                                 do_rmd(user_cmd.arg);
 176                                 break;
 177                 case 12:
 178                                 debug_printf("call mkd()\n");
 179                                 do_mkd(user_cmd.arg);
 180                                 break;
 181                 case 13:
 182                                 debug_printf("call pwd()\n");
 183                                 do_pwd();
 184                                 break;
 185                 case 14:
 186                                 debug_printf("call cwd()\n");
 187                                 do_cwd(user_cmd.arg);
 188                                 break;
 189                 case 15:
 190                                 debug_printf("call cdup()\n");
 191                                 do_cdup();
 192                                 break;
 193                 case 16:
 194                                 debug_printf("call port()\n");
 195                                 do_port(user_cmd.arg);
 196                                 break;
 197                 case 17:
 198                                 debug_printf("call noop()\n");
 199                                 do_noop();
 200                                 break;
 201                 case 18:
 202                                 debug_printf("call pasv()\n\n");
 203                                 do_pasv();
 204                                 break;
 205                 case 19:
 206                                 debug_printf("call type()\n");
 207                                 do_type(user_cmd.arg);
 208                                 break;
 209                 case 20:
 210                                 debug_printf("call mode()\n");
 211                                 do_mode(user_cmd.arg);
 212                                 break;
 213                 case 21:
 214                                 debug_printf("call stat()\n");
 215                                 do_stat(user_cmd.arg);
 216                                 break;
 217                 case 22:
 218                                 debug_printf("call stru()\n");
 219                                 do_stru(user_cmd.arg);
 220                                 break;
 221                 case 23:
 222                                 debug_printf("call list()\n");
 223                                 do_list(user_cmd.arg);
 224                                 break;
 225                 default:
 226                                 debug_printf("call failed()\n");
 227                                 failed(user_cmd.cmd);
 228                                 break;
 229                 }
 230         } else if (i <= 23 && i >= 1) {
 231                 write(user_env.connect_fd, login_error, strlen(login_error));
 232         } else {
 233                 failed(user_cmd.cmd);
 234         }
 235         return 1;
 236 }