diff --git a/day3/homework/02.jpg b/day3/homework/02.jpg
new file mode 100644
index 0000000..f6fbca5
Binary files /dev/null and b/day3/homework/02.jpg differ
diff --git a/day3/homework/h3 b/day3/homework/h3
new file mode 100755
index 0000000..e618005
Binary files /dev/null and b/day3/homework/h3 differ
diff --git a/day3/homework/h3.c b/day3/homework/h3.c
new file mode 100644
index 0000000..d5e7edd
--- /dev/null
+++ b/day3/homework/h3.c
@@ -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;
+}
diff --git a/day4/test.c b/day4/test.c
new file mode 100644
index 0000000..238e27b
--- /dev/null
+++ b/day4/test.c
@@ -0,0 +1,196 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <arpa/inet.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <pthread.h>
+
+#define BUFFLEN 1024  //缓冲区的大小 
+#define SERVER_PORT 1235  //端口号
+#define HTTP_FILENAME_LEN   256
+
+struct doc_type
+{
+    char *suffix;
+    char *type;
+};
+//返回内容对应 MIME 类型
+struct doc_type file_type[] =
+{
+    { "html", "text/html" },
+    { "ico", "image/x-icon" },
+    { NULL, NULL }
+};
+void * threadFun(void * args);
+void handle_connect(int serv_sock);
+void http_parse_request_cmd(char *buf,char *file_name, char *suffix);
+char *http_get_type_by_suffix(const char *suffix);
+
+char *http_res_hdr_tmpl = "HTTP/1.1 200 OK\nServer: bianchengbang\n"
+"Accept-Ranges: bytes\nContent-Length: %d\nConnection: closed\n"
+"Content-Type: %s\n\n";
+
+int main() {
+    int serv_sock;
+    struct sockaddr_in serv_addr;
+    //创建套接字
+    if ((serv_sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1) {
+        printf("套接字创建失败\n");
+        exit(0);
+    }
+
+    //将套接字与任意 IP 地址和 1234 端口进行绑定
+    memset(&serv_addr, 0, sizeof(serv_addr));
+    serv_addr.sin_family = AF_INET;
+    serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
+    serv_addr.sin_port = htons(SERVER_PORT);
+    if (bind(serv_sock, (struct sockaddr*)&serv_addr, sizeof(serv_addr)) == -1) {
+        close(serv_sock);
+        printf("bind()执行失败\n");
+        exit(0);
+    }
+
+    //让套接字进入被动监听状态
+    if (listen(serv_sock, SOMAXCONN) == -1) {
+        close(serv_sock);
+        printf("listen()执行失败\n");
+        exit(0);
+    }
+
+    handle_connect(serv_sock);
+    close(serv_sock);
+    return 0;
+}
+
+void handle_connect(int serv_sock){
+    int clnt_sock;
+    struct sockaddr_in clnt_addr;
+    socklen_t clnt_addr_size = sizeof(clnt_addr);
+    //死循环，持续不断地接收任意客户端发来的请求
+    while(1){
+        clnt_sock = accept(serv_sock, (struct sockaddr*)&clnt_addr, &clnt_addr_size);//接收客户端发来的请求
+        //单独创建一个线程，处理客户端的请求
+        if(clnt_sock >0){
+            pthread_t myThread;
+            int ret;
+            //threadFun() 为线程要执行的函数，clnt_sock 将作为实参传递给 threadFun() 函数
+            ret = pthread_create(&myThread, NULL, threadFun, &clnt_sock);
+            if (ret != 0) {
+                printf("线程创建失败\n");
+                exit(0);
+            }
+        }
+    }
+}
+
+void * threadFun(void * args) {
+    //将子线程和主线程脱离，子线程执行结束后自动释放资源
+    pthread_detach(pthread_self());
+    int clnt_sock = *(int*)args;
+    char buff[BUFFLEN]={0};
+    //获取http请求的字符串，num 为字符串的长度
+    int  num = read(clnt_sock, buff, sizeof(buff));
+    if (num > 0) {
+        FILE * fp = NULL;
+        int nCount = 0;
+        int fp_has = 1,fp_type = 1;
+        int file_len, hdr_len;
+        char *type = NULL;
+        char http_header[BUFFLEN];
+        char file_name[HTTP_FILENAME_LEN] = { 0 }, suffix[16] = { 0 };
+        //获取目标文件（含路径）和后缀名
+        http_parse_request_cmd(buff, file_name, suffix);
+        //获取文件对应的 MIME 类型
+        type = http_get_type_by_suffix(suffix);
+        //如果类型未找到，则向客户端发送 errno.html 文件
+        if (type == NULL)
+        {
+            fp_type = 0;
+            printf("访问的文件类型（后缀名）不匹配\n");
+            type = http_get_type_by_suffix("html");
+            fp = fopen("errno.html","rb");
+        }else{
+            fp = fopen(file_name, "rb");
+            //如果服务器未找到目标文件，向客户端发送 errno.html 文件
+            if (fp == NULL) {
+                fp_has = 0;
+                fp = fopen("errno.html","rb");
+            }
+        }
+        //计算文件中包含的字节数
+        fseek(fp, 0, SEEK_END);
+        file_len = ftell(fp);
+        fseek(fp, 0, SEEK_SET);
+        //更新 http 响应的字符串
+        hdr_len = sprintf(http_header, http_res_hdr_tmpl, file_len, type);
+        //向客户端发送响应行、响应头和空行
+        write(clnt_sock, http_header, hdr_len);
+
+        if(fp_type == 1){
+            if (fp_has == 0) {
+                printf("服务器不存在 %s 文件\n", file_name);
+            }
+            else {
+                printf("服务器存在 %s 文件，发送中...\n",file_name);
+            }
+        }
+        //向客户端发送文件内容，即响应体
+        memset(buff, 0, BUFFLEN);
+        while ((nCount = fread(buff, 1, BUFFLEN, fp)) > 0) {
+            write(clnt_sock, buff, nCount);
+            memset(buff, 0, BUFFLEN);
+        }
+        fclose(fp);
+        shutdown(clnt_sock, SHUT_WR);
+        read(clnt_sock, buff, sizeof(buff));
+        close(clnt_sock);
+    }
+    return NULL;
+}
+
+char *http_get_type_by_suffix(const char *suffix)
+{
+    struct doc_type *type = NULL;
+
+    for (type = file_type; type->suffix; type++)
+    {
+        if (strcmp(type->suffix, suffix) == 0)
+            return type->type;
+    }
+
+    return NULL;
+}
+
+void http_parse_request_cmd(char *buf,char *file_name, char *suffix)
+{
+    int file_length = 0, suffix_length = 0;
+    char *begin=NULL, *end=NULL, *bias=NULL;
+
+    //查找 URL 的开始位置
+    begin = strchr(buf, ' ');
+    begin += 1;
+
+    //查找 URL 的结束位置
+    end = strchr(begin, ' ');
+    *end = 0;
+    //得到要访问的目标文件（含路径）
+    file_length = end - begin - 1;
+    memcpy(file_name, begin+1, file_length);
+    file_name[file_length] = 0;
+    //获得文件的后缀名
+    bias = strrchr(begin, '/');
+    suffix_length = end - bias;
+    if (*bias == '/')
+    {
+        bias++;
+        suffix_length--;
+    }
+    if (suffix_length > 0)
+    {
+        begin = strchr(file_name, '.');
+        if (begin)
+            strcpy(suffix, begin + 1);
+    }
+}
\ No newline at end of file
diff --git a/day5/weak_task/client b/day5/weak_task/client
new file mode 100755
index 0000000..07588cb
Binary files /dev/null and b/day5/weak_task/client differ
diff --git a/day5/weak_task/server b/day5/weak_task/server
new file mode 100755
index 0000000..8b83f9c
Binary files /dev/null and b/day5/weak_task/server differ
diff --git a/day5/weak_task/t5.c b/day5/weak_task/t5.c
new file mode 100644
index 0000000..9d0c8b8
--- /dev/null
+++ b/day5/weak_task/t5.c
@@ -0,0 +1,43 @@
+// a->客户端
+#include <stdio.h>
+#include <string.h>
+#include <arpa/inet.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
+#include <unistd.h>
+
+int main(int argc, char const *argv[])
+{
+    int a_fd = socket(AF_INET, SOCK_DGRAM, 0);
+    if (a_fd < 0)
+    {
+        perror("socket");
+        return 1;
+    }
+
+    struct sockaddr_in addr;
+    bzero(&addr, sizeof(addr));
+    addr.sin_family = AF_INET;
+    addr.sin_port = htons(8000);
+    addr.sin_addr.s_addr = inet_addr("127.0.0.1"); // 服务器在本地
+
+    while (1)
+    {
+        char buf[1] = "";
+        bzero(&buf, sizeof(buf));
+        scanf("%s", buf);
+        sendto(a_fd, buf, strlen(buf), 0, (struct sockaddr *)&addr, sizeof(addr));
+
+        char recvbuf[128] = "";
+        socklen_t addr_len = sizeof(addr);
+        recvfrom(a_fd, recvbuf, strlen(recvbuf), 0, (struct sockaddr *)&addr, &addr_len);
+        printf("%s", recvbuf);
+
+        if (strncmp(recvbuf, "bye", 3) == 0)
+            break;
+    }
+
+    close(a_fd);
+
+    return 0;
+}
diff --git a/day5/weak_task/t5_a.c b/day5/weak_task/t5_a.c
new file mode 100644
index 0000000..f90777e
--- /dev/null
+++ b/day5/weak_task/t5_a.c
@@ -0,0 +1,42 @@
+// a->客户端
+#include <stdio.h>
+#include <string.h>
+#include <arpa/inet.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
+#include <unistd.h>
+
+int main(int argc, char const *argv[])
+{
+    int a_fd = socket(AF_INET, SOCK_DGRAM, 0);
+    if (a_fd < 0)
+    {
+        perror("socket");
+        return 1;
+    }
+
+    struct sockaddr_in addr;
+    bzero(&addr, sizeof(addr));
+    addr.sin_family = AF_INET;
+    addr.sin_port = htons(8000);
+    addr.sin_addr.s_addr = inet_addr("127.0.0.1"); // 服务器在本地
+
+    while (1)
+    {
+        int n = 0;
+        scanf("%d", &n);
+        sendto(a_fd, &n, sizeof(n), 0, (struct sockaddr *)&addr, sizeof(addr));
+
+        char recvbuf[128] = "";
+        socklen_t addr_len = sizeof(addr);
+        recvfrom(a_fd, recvbuf, strlen(recvbuf), 0, (struct sockaddr *)&addr, &addr_len);
+        printf("%s", recvbuf);
+
+        if (strncmp(recvbuf, "bye", 3) == 0)
+            break;
+    }
+
+    close(a_fd);
+
+    return 0;
+}
diff --git a/day5/weak_task/t5_b.c b/day5/weak_task/t5_b.c
new file mode 100644
index 0000000..483ae28
--- /dev/null
+++ b/day5/weak_task/t5_b.c
@@ -0,0 +1,54 @@
+// b->服务端
+#include <stdio.h>
+#include <string.h>
+#include <arpa/inet.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
+#include <unistd.h>
+#include <stdlib.h>
+
+int main(int argc, char const *argv[])
+{
+    int b_fd = socket(AF_INET, SOCK_DGRAM, 0);
+    if (b_fd < 0)
+    {
+        perror("socket");
+        return 1;
+    }
+
+    struct sockaddr_in addr;
+    bzero(&addr, sizeof(addr));
+    addr.sin_family = AF_INET;
+    addr.sin_port = htons(8000);
+    addr.sin_addr.s_addr = htonl(INADDR_ANY); // 接收所有本地ip下同一网段的客户端消息
+    // addr.sin_addr.s_addr = inet_addr("127.0.0.1");
+    bind(b_fd, (struct sockaddr *)&addr, sizeof(addr));
+
+    while (1)
+    {
+        struct sockaddr_in src_addr;
+        bzero(&src_addr, sizeof(src_addr));
+        socklen_t src_addr_len = sizeof(src_addr);
+        int n;
+        socklen_t addr_len = sizeof(addr);
+        recvfrom(b_fd, &n, sizeof(n), 0, (struct sockaddr *)&src_addr, &src_addr_len);
+        printf("%d", n);
+
+        char sendbuf[128] = "";
+
+        if (n == 1)
+            strcpy(sendbuf, "disen666");
+        else if (n == 2)
+            strcpy(sendbuf, "jack good");
+        else if (n == 3)
+            strcpy(sendbuf, "disen888");
+        else if (n == 4)
+            strcpy(sendbuf, "bye");
+
+        sendto(b_fd, sendbuf, strlen(sendbuf), 0, (struct sockaddr *)&src_addr, src_addr_len);
+    }
+
+    close(b_fd);
+
+    return 0;
+}