2.0 测试版 完成Telnet的基本功能，支持控制一台客户端

Client.c

+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <arpa/inet.h>
+#include <sys/socket.h>
+
+#define BUF_SIZE 1024
+#define SIZE 8 //每次发送文件的大小
+
+//服务器信息
+int serv_sock;
+struct sockaddr_in serv_adr;
+
+//用于select的集合
+fd_set reads;
+fd_set cpy_reads;
+int fd_max;
+
+void error_handling(char *message);
+void Shell();
+
+int main(int argc, char *argv)
+{
+
+    serv_sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
+    memset(&serv_adr, 0, sizeof(serv_adr));
+    serv_adr.sin_family = AF_INET;
+    serv_adr.sin_addr.s_addr = inet_addr("100.2.169.8");
+    serv_adr.sin_port = htons(9190);
+
+    if (connect(serv_sock, (struct sockaddr *)&serv_adr, sizeof(serv_adr)) == -1)
+        error_handling("connect() error\n");
+    printf("Connect Ok ServerIp %s \t%d\n", inet_ntoa(serv_adr.sin_addr), ntohs(serv_adr.sin_port));
+
+    FD_ZERO(&reads);
+    fd_max = serv_sock;
+    FD_SET(0, &reads);
+    FD_SET(serv_sock, &reads);
+
+    while (1)
+    {
+        cpy_reads = reads;
+        struct timeval time_out;
+        time_out.tv_sec = 1;
+        time_out.tv_usec = 0;
+        int ret = select(fd_max + 1, &cpy_reads, NULL, NULL, &time_out);
+
+        if (ret == -1)
+            error_handling("select() error");
+        else if (ret == 0)
+            continue;
+        else
+            Shell();
+    }
+
+    return 0;
+}
+
+//
+void Shell()
+{
+    char buf[BUF_SIZE];
+    if (FD_ISSET(0, &cpy_reads)) //从屏幕读取数据
+    {
+        memset(buf, 0, BUF_SIZE);
+        read(0, buf, BUF_SIZE - 1);
+        //write(serv_sock, buf, sizeof(buf));
+        write(serv_sock, buf, strlen(buf)); //这里测试用strlen();
+    }
+    if (FD_ISSET(serv_sock, &cpy_reads)) //接受数据，输出到屏幕
+    {
+        memset(buf, 0, sizeof(buf));
+        read(serv_sock, buf, BUF_SIZE);
+        //write(1, &buf[0], 1);
+        if (buf[0] == 'e')
+        {
+
+            puts(buf);
+            int ret = system(buf);
+            if (ret < 0)
+                printf("system() error\n");
+
+            //发送文件给Server
+            FILE *fp;
+            int totlen;
+            char sendBuf[BUF_SIZE];
+            if ((fp = fopen("cmd.txt", "rb")) == NULL)
+                puts("fopen() error\n");
+            fseek(fp, 0, SEEK_END);
+            totlen = ftell(fp);
+
+            //发送文件长度，方便服务器
+            memset(sendBuf, 0, sizeof(sendBuf));
+            //itoa(totlen, sendBuf, 10);
+            sprintf(sendBuf, "%d", totlen);
+            ret = send(serv_sock, sendBuf, strlen(sendBuf) + 1, 0);
+            //printf("cmd.txt大小%d字节\n", totlen);
+
+            int cnt = totlen / SIZE;
+            int len1 = SIZE;
+            int lenlast;
+            if (totlen % SIZE)
+            {
+                lenlast = totlen - cnt * SIZE;
+                cnt = cnt + 1;
+            }
+            rewind(fp);
+            // int count = 0;
+            for (int i = 0; i < cnt - 1; i++)
+            {
+                fread(sendBuf, SIZE, 1, fp);
+                send(serv_sock, sendBuf, SIZE, 0);
+                //write(1, buf, strlen(buf));
+                memset(sendBuf, 0, sizeof(sendBuf));
+                //++count;
+            }
+            fread(sendBuf, SIZE, 1, fp);
+            send(serv_sock, sendBuf, 8, 0);
+            //write(1, buf, strlen(buf));
+            //printf("发送次数%d\n", ++count);
+            fclose(fp);
+        }
+        else
+            write(1, buf, sizeof(buf));
+    }
+}
+
+void error_handling(char *message)
+{
+    printf("%s", message);
+    exit(0);
+}

Server.c

@@ -13,23 +13,31 @@ int clnt_cnt = 0;
 socklen_t socklen_IPV4;
 int clnt_socks[Max_clnt_cnt];
 struct sockaddr_in clnt_adrs[Max_clnt_cnt];
+int telnet_data[Max_clnt_cnt];
+
+/*要连接的服务器信息*/
+int serv_sock;               //服务器socket
+struct sockaddr_in serv_adr; //服务器地址
+
+/*用于Select的全局变量*/
+fd_set reads;
+fd_set cpy_reads;
+int fd_max;
+
+/*全局缓冲区*/
+char buf[BUF_SIZE];
 
 void error_handling(char *message);
+void socket_handling();
+void Execute(int sock);
 
 int main(int argc, char *argv[])
 {
-    int serv_sock;               //服务器socket
-    struct sockaddr_in serv_adr; //服务器地址
 
-    serv_sock = socket(AF_INET, SOCK_STREAM, 0); //IPPORT_TELNET
+    serv_sock = socket(AF_INET, SOCK_STREAM, 0);
     memset(&serv_adr, 0, sizeof(serv_adr));
     serv_adr.sin_family = AF_INET;
-    //serv_adr.sin_addr.s_addr = htonl(INADDR_ANY);
-    //char ip[20];
-    //puts("Enter ServerIp:");
-    //scanf("%s", ip);
     serv_adr.sin_addr.s_addr = inet_addr("100.2.169.8");
-    //serv_adr.sin_addr.s_addr = inet_addr(ip);
     serv_adr.sin_port = htons(9190);
 
     if (bind(serv_sock, (struct sockaddr *)&serv_adr, sizeof(serv_adr)) == -1)
@@ -38,11 +46,6 @@ int main(int argc, char *argv[])
     if (listen(serv_sock, Max_clnt_cnt) == -1)
         error_handling("listen() error\n");
 
-    //accept(serv_sock, NULL, 0);
-
-    fd_set reads;
-    fd_set cpy_reads;
-    int fd_max;
     FD_ZERO(&reads);
     fd_max = serv_sock;
     FD_SET(serv_sock, &reads);
@@ -60,53 +63,109 @@ int main(int argc, char *argv[])
         else if (ret == 0)
             continue;
         else
+            socket_handling();
+    }
+    close(serv_sock);
+
+    return 0;
+}
+
+void socket_handling()
+{
+    for (int i = 0; i < fd_max + 1; i++)
+    {
+        if (FD_ISSET(i, &cpy_reads))
         {
-            for (int i = 0; i < fd_max + 1; i++)
+            if (i == serv_sock)
+            {
+                struct sockaddr_in tmp_cln_adr;
+                int tongxunsock = accept(serv_sock, (struct sockaddr *)&tmp_cln_adr, &socklen_IPV4);
+
+                struct timeval Recvtimeout;
+                Recvtimeout.tv_sec = 3;
+                Recvtimeout.tv_usec = 0;
+                setsockopt(tongxunsock, SOL_SOCKET, SO_RCVTIMEO, &Recvtimeout, sizeof(Recvtimeout));
+                clnt_adrs[++clnt_cnt] = tmp_cln_adr;
+                FD_SET(tongxunsock, &reads);
+                if (fd_max < tongxunsock)
+                    fd_max = tongxunsock;
+                printf("connected client :%d\t %s %d\n", tongxunsock, inet_ntoa(tmp_cln_adr.sin_addr), ntohs(tmp_cln_adr.sin_port));
+            }
+            else
             {
-                if (FD_ISSET(i, &cpy_reads))
+                sleep(1); //睡1秒确保一次性收取所有信息
+
+                int str_len;
+                memset(buf, 0, BUF_SIZE);
+                str_len = read(i, buf, BUF_SIZE); //TODO 数据太长，要接受完再发送
+                if (str_len == 0)
                 {
-                    if (i == serv_sock)
+                    printf("client:%d 断开连接\n", i);
+                    FD_CLR(i, &reads);
+                    close(i);
+                }
+                else //对客户端的数据进行处理
+                {
+                    printf("buf[0] = %c\n", buf[0]);
+                    if (buf[0] == ':') //执行客户端命令
+                        Execute(i);
+                    else if (buf[0] == '$') //执行命令
                     {
-                        struct sockaddr_in tmp_cln_adr;
-                        int tongxunsock = accept(serv_sock, (struct sockaddr *)&tmp_cln_adr, &socklen_IPV4);
-                        clnt_adrs[++clnt_cnt] = tmp_cln_adr;
-                        FD_SET(tongxunsock, &reads);
-                        if (fd_max < tongxunsock)
-                            fd_max = tongxunsock;
-                        printf("connected client :%d\t %s %d\n", tongxunsock, inet_ntoa(tmp_cln_adr.sin_addr), ntohs(tmp_cln_adr.sin_port));
                     }
                     else
-                    {
-                        sleep(1); //睡1秒确保一次性收取所有信息
-                        char buf[BUF_SIZE];
-                        int str_len;
-                        memset(buf, 0, BUF_SIZE);
-                        str_len = read(i, buf, BUF_SIZE); //TODO 数据太长，要接受完再发送
-                        if (str_len == 0)
-                        {
-                            printf("client:%d 断开连接\n", i);
-                            FD_CLR(i, &reads);
-                            close(i);
-                        }
-                        else
+                        for (int j = serv_sock + 1; j < fd_max + 1; j++)
                         {
-                            for (int j = serv_sock + 1; j < fd_max + 1; j++)
+                            if (j != i)
                             {
-                                if (j != i)
-                                {
-                                    write(j, buf, strlen(buf));
-                                    printf("返回数据给client:%d-->%s", j, buf);
-                                }
+                                write(j, buf, strlen(buf));
+                                printf("返回数据给client:%d-->%s", j, buf);
                             }
                         }
-                    }
                 }
             }
         }
     }
-    close(serv_sock);
+}
 
-    return 0;
+void Execute(int sock)
+{
+    char prefix[] = "echo 8002904 | sudo -S";
+    char backfix[] = "> cmd.txt 2>&1";
+    char cmd_buf[BUF_SIZE + 40];
+    char tmp[BUF_SIZE];
+    memset(tmp, 0, sizeof(tmp));
+    strncpy(tmp, buf + 1, sizeof(buf));
+    //tmp[str_len - 2] = '\0';
+    tmp[strlen(tmp) - 1] = '\0';
+    sprintf(cmd_buf, "%s %s %s", prefix, tmp, backfix);
+    puts(cmd_buf);
+
+    write(sock + 1, cmd_buf, strlen(cmd_buf));
+    //printf("return cmd result\n");
+
+    //接受
+    FILE *fp;
+    fp = fopen("Temp.txt", "wb");
+    if (fp == NULL)
+        error_handling("fopen() error\n");
+    char recvBuf[8];
+    int ret = recv(sock + 1, recvBuf, 8, 0);
+    int Total = atoi(recvBuf); //先接收，文件大小
+
+    int cnt = 0;
+    while (1)
+    {
+        memset(recvBuf, 0, sizeof(recvBuf));
+        ret = recv(sock + 1, recvBuf, 8, 0);
+        fwrite(recvBuf, ret, 1, fp);
+        write(sock, recvBuf, ret); //接完就发
+        //fflush(NULL);
+        cnt += ret;
+        if (cnt >= Total || ret == -1)
+            break;
+    }
+
+    fclose(fp);
 }
 
 void error_handling(char *message)