其他

2023-09-18 17:50:11 +08:00
parent dd22bec895
commit 5cdb1cc311
9 changed files with 430 additions and 0 deletions
@@ -0,0 +1,95 @@
+#include <stdio.h>
+#include <arpa/inet.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <unistd.h>
+#include <string.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+/*
+./a.out server_ip 下载的文件名
+*/
+int main(int argc, char const *argv[])
+{
+    if (argc != 3)
+    {
+        printf("usage: %s server_ip filename\n", argv[0]);
+        return -1;
+    }
+
+    int sock_fd = socket(AF_INET, SOCK_DGRAM, 0);
+    if (sock_fd < 0)
+    {
+        perror("socket");
+        return -1;
+    }
+
+    struct stat st;
+    stat(argv[2], &st);
+    int tsize = st.st_size;
+    // 生成请求数据包
+    char request[64];
+    // char *tsize = 0;
+    int request_size = sprintf(request, "%c%c%s%c%s%c%d%c", 0, 1, argv[2], 0, "octet", 0, tsize, 0);
+
+    // 发送请求
+    struct sockaddr_in server_addr;
+    bzero(&server_addr, sizeof(server_addr));
+    server_addr.sin_family = AF_INET;
+    server_addr.sin_port = htons(69);                 // 服务器TFTP端口
+    server_addr.sin_addr.s_addr = inet_addr(argv[1]); // 服务器地址
+
+    sendto(sock_fd, request, request_size, 0, (struct sockaddr *)&server_addr, sizeof(server_addr));
+
+    char buf[516] = "";
+    struct sockaddr_in data_addr;
+    socklen_t data_addr_len = sizeof(data_addr);
+    bzero(&data_addr, sizeof(data_addr));
+    ssize_t len = recvfrom(sock_fd, buf, 516, 0, (struct sockaddr *)&data_addr, &data_addr_len);
+
+    // 验证接收的数据是否是 OK
+    if (buf[1] == 3)
+    {
+        // printf("收到的文件大小为 %d\n", tsize);
+        // 创建本地文件的描述符（打开或创建文件）
+        int fd = open(argv[2], O_CREAT | O_WRONLY, 0666);
+
+        while (1)
+        {
+            printf("文件名为 %s,文件大小为 %s\n", argv[2], buf + 2);
+
+            // 收到的是数据报
+            write(fd, buf + 4, len - 4);
+            // 回ACK
+            buf[1] = 4;
+            // buf[2] = "tsize";
+            sendto(sock_fd, buf, 4, 0, (struct sockaddr *)&data_addr, sizeof(data_addr));
+            if (len < 516)
+            {
+                printf("数据接收完成\n");
+                break;
+            }
+
+            bzero(&data_addr, data_addr_len);
+            bzero(buf, sizeof(buf));
+            len = recvfrom(sock_fd, buf, 516, 0, (struct sockaddr *)&data_addr, &data_addr_len);
+        }
+
+        close(fd);
+    }
+    else if (buf[1] == 5)
+    {
+        // 收到的是错误信息
+        printf("error: %s\n", buf + 4);
+    }
+    // else if (buf[1] == 6)
+    // {
+    //     // 收到OACK包，包含请求选项回传的值
+    //     printf("文件名为 %s,文件大小为 %s\n", argv[2], buf + 2);
+    // }
+
+    close(sock_fd);
+    return 0;
+}