CProxy/httpudp.c

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16 KiB
C
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/*
HTTPUDP模块代理UDP过程:
获取客户端UDP数据
向服务器发送一个http请求头
收到服务端回应后发送数据到服务端,内容为: UDP原始目标地址[struct in_addr](只有第一个数据包发送) + UDP长度[uint16_t] + UDP真实数据
服务端返回数据,数据内容为: UDP包的长度[uint16_t] + UDP真实数据
新建一个socket伪装原目标地址向客户端发送返回的数据(此功能需要root否则部分UDP代理不上例如QQ语音)
*/
#include "http_request.h"
#include "httpudp.h"
#define MAX_CLIENT_INFO 512
#define HTTP_RSP_SIZE 2048
#define CLIENT_BUFFER_SIZE 65535 //如果可以 尽量一次性读完数据
#define SERVER_BUFFER_SIZE 8192
typedef struct connection_info {
char client_data[CLIENT_BUFFER_SIZE + sizeof(struct sockaddr_in) + sizeof(uint16_t)];
struct sockaddr_in inaddr, toaddr;
struct connection_info *next;
char *rsp_data;
int client_data_len, client_data_sent_len, http_request_sent_len, rsp_data_len, rsp_data_sent_len, server_fd, responseClientFd, timer;
} info_t;
static info_t client_info_list[MAX_CLIENT_INFO];
static struct epoll_event udp_evs[MAX_CLIENT_INFO * 2 + 2], udp_ev;
struct httpudp udp;
static int udp_efd;
static void proxyStop(info_t * info)
{
epoll_ctl(udp_efd, EPOLL_CTL_DEL, info->server_fd, NULL);
epoll_ctl(udp_efd, EPOLL_CTL_DEL, info->responseClientFd, NULL);
close(info->server_fd);
close(info->responseClientFd);
free(info->rsp_data);
info->rsp_data = NULL;
do {
info->server_fd = info->responseClientFd = -1;
info->rsp_data_len = info->rsp_data_sent_len = info->client_data_sent_len = info->http_request_sent_len = 0;
} while ((info = info->next) != NULL);
}
void udp_timeout_check()
{
int i;
for (i = 0; i < MAX_CLIENT_INFO; i++) {
if (client_info_list[i].server_fd > -1) {
if (client_info_list[i].timer >= global.timeout_m)
proxyStop(client_info_list + i);
else
client_info_list[i].timer = 0;
}
}
}
/* 创建udpfd回应客户端 */
static int createRspFd(info_t * client)
{
int opt = 1;
client->responseClientFd = socket(AF_INET, SOCK_DGRAM, 0);
if (client->responseClientFd < 0)
return 1;
fcntl(client->responseClientFd, F_SETFL, O_NONBLOCK);
/*
以下函数不做返回值判断
因为有些UDP客户端不需要伪装源目标地址
*/
setsockopt(client->responseClientFd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
setsockopt(client->responseClientFd, SOL_IP, IP_TRANSPARENT, &opt, sizeof(opt));
//切换root伪装源目标地址
seteuid(0);
setegid(0);
bind(client->responseClientFd, (struct sockaddr *)&client->toaddr, sizeof(struct sockaddr_in));
//切换回用户设置的uid
setegid(global.uid);
seteuid(global.uid);
return 0;
}
/* 将服务端返回的数据发送到客户端 */
static int outputToClient(info_t * client)
{
char *dataPtr;
int write_len;
if (client->responseClientFd < 0 && createRspFd(client) < 0)
return 1;
client->timer = 0;
dataPtr = client->rsp_data;
//至少要有一个完整的udp包才返回客户端
while ((int)(*(uint16_t *) dataPtr + sizeof(uint16_t)) <= client->rsp_data_len) {
write_len = sendto(client->responseClientFd, dataPtr + sizeof(uint16_t) + client->rsp_data_sent_len, *(uint16_t *) dataPtr - client->rsp_data_sent_len, 0, (struct sockaddr *)&client->inaddr, sizeof(struct sockaddr_in));
//printf("rsp: [write_len:%d, dataLen:%u, sent:%u, total:%d]\n", write_len, *(uint16_t *)dataPtr, client->rsp_data_sent_len, client->rsp_data_len);
if (write_len < 0 && errno == EAGAIN)
return 0;
client->rsp_data_sent_len += write_len;
if (write_len == 0 || write_len < 0) {
//perror("toClient write()");
return 1;
}
if (write_len < *(uint16_t *) dataPtr) {
udp_ev.data.ptr = client;
udp_ev.events = EPOLLIN | EPOLLOUT | EPOLLET;
epoll_ctl(udp_efd, EPOLL_CTL_ADD, client->responseClientFd, &udp_ev);
return 0;
}
dataPtr += write_len + sizeof(uint16_t);
client->rsp_data_len -= write_len + sizeof(uint16_t);
client->rsp_data_sent_len = 0;
}
//发送完已读取到的所有数据 释放内存
if (client->rsp_data_len == 0) {
free(client->rsp_data);
client->rsp_data = NULL;
udp_ev.data.ptr = client;
udp_ev.events = EPOLLIN | EPOLLET;
epoll_ctl(udp_efd, EPOLL_CTL_MOD, client->responseClientFd, &udp_ev);
}
//还有数据未返回给客户端,将未返回的数据复制到内存头
else if (dataPtr > client->rsp_data) {
memmove(client->rsp_data, dataPtr, client->rsp_data_len);
}
return 0;
}
/* 读取服务器的数据并返回给客户端 */
static void recvServer(info_t * in)
{
in->timer = 0;
//当条件成立时表示未接收https回应状态码
if (udp.http_request_len == in->http_request_sent_len) {
static char http_rsp[HTTP_RSP_SIZE];
int read_len;
do {
read_len = read(in->server_fd, http_rsp, HTTP_RSP_SIZE);
if (read_len == 0 || (read_len < 0 && errno != EAGAIN)) {
proxyStop(in);
return;
}
} while (read_len == HTTP_RSP_SIZE);
in->http_request_sent_len++; //不再接收http头
udp_ev.data.ptr = in;
udp_ev.events = EPOLLIN | EPOLLOUT | EPOLLET;
epoll_ctl(udp_efd, EPOLL_CTL_MOD, in->server_fd, &udp_ev);
return;
}
char *new_data;
int read_len;
do {
new_data = (char *)realloc(in->rsp_data, in->rsp_data_len + SERVER_BUFFER_SIZE);
if (new_data == NULL) {
proxyStop(in);
return;
}
in->rsp_data = new_data;
read_len = read(in->server_fd, in->rsp_data + in->rsp_data_len, SERVER_BUFFER_SIZE);
/* 判断是否关闭连接 */
if (read_len <= 0) {
if (read_len == 0 || errno != EAGAIN || in->rsp_data_len == 0) {
proxyStop(in);
return;
}
read_len = 0;
break;
}
if (udp.httpsProxy_encodeCode)
dataEncode(in->rsp_data + in->rsp_data_len, read_len, udp.httpsProxy_encodeCode);
if (udp.encodeCode)
dataEncode(in->rsp_data + in->rsp_data_len, read_len, udp.encodeCode);
in->rsp_data_len += read_len;
} while (read_len == SERVER_BUFFER_SIZE);
outputToClient(in);
}
/* 向服务器发送数据 */
static int sendToServer(info_t * out)
{
info_t *send_info;
int len;
out->timer = 0;
/* 发送http请求头到服务器 */
if (udp.http_request_len > out->http_request_sent_len) {
len = write(out->server_fd, udp.http_request + out->http_request_sent_len, udp.http_request_len - out->http_request_sent_len);
if (len <= 0) {
if (len == 0 || errno != EAGAIN)
return 1;
return 0;
}
if (len > 0) {
out->http_request_sent_len += len;
if (udp.http_request_len == out->http_request_sent_len) {
udp_ev.data.ptr = out;
udp_ev.events = EPOLLIN | EPOLLET;
epoll_ctl(udp_efd, EPOLL_CTL_MOD, out->server_fd, &udp_ev);
}
}
return 0;
}
/* 发送UDP目标地址,UDP数据长度和UDP真实数据到服务器 */
for (send_info = out; send_info; send_info = send_info->next) {
if (send_info->client_data_len == send_info->client_data_sent_len)
continue;
len = write(out->server_fd, send_info->client_data + send_info->client_data_sent_len, send_info->client_data_len - send_info->client_data_sent_len);
//printf("server_fd: %d, write_len: %d, udp_len: %d, sent_le: %d\n", out->server_fd, len, send_info->client_data_len - send_info->client_data_sent_len, send_info->client_data_sent_len);
if (len <= 0) {
if (len == 0 || errno != EAGAIN)
return 1;
break;
}
send_info->client_data_sent_len += len;
if (send_info->client_data_sent_len < send_info->client_data_len)
break;
if (send_info != out) {
//此结构体已用完
send_info->server_fd = -1;
send_info->client_data_sent_len = 0;
}
}
if (send_info == NULL) {
udp_ev.data.ptr = out;
udp_ev.events = EPOLLIN | EPOLLET;
epoll_ctl(udp_efd, EPOLL_CTL_MOD, out->server_fd, &udp_ev);
}
out->next = send_info;
return 0;
}
static void outEvent(info_t * out)
{
if (out->server_fd == -1)
return;
if ((out->rsp_data && outputToClient(out) != 0) || sendToServer(out) != 0)
proxyStop(out);
}
static int recvClient(info_t * client)
{
static char control[1024];
struct msghdr msg;
struct iovec io;
struct cmsghdr *cmsg;
msg.msg_name = &client->inaddr;
msg.msg_namelen = sizeof(client->inaddr);
msg.msg_iov = &io;
msg.msg_iovlen = 1;
msg.msg_control = control;
msg.msg_controllen = sizeof(control);
io.iov_base = client->client_data + sizeof(struct sockaddr_in) + sizeof(uint16_t);
io.iov_len = CLIENT_BUFFER_SIZE;
client->client_data_len = recvmsg(global.udp_listen_fd, &msg, 0);
if (client->client_data_len <= 0) {
//perror("recvmsg()");
return 1;
}
/* 取得客户端目标地址 */
for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg))
if (cmsg->cmsg_level == SOL_IP && cmsg->cmsg_type == IP_ORIGDSTADDR && cmsg->cmsg_len >= CMSG_LEN(sizeof(client->toaddr))) {
memcpy(&client->toaddr, CMSG_DATA(cmsg), sizeof(client->toaddr));
break;
}
if (cmsg == NULL)
return 1;
/*
printf("src ip: [%s], port: [%d]\n", inet_ntoa(client->inaddr.sin_addr), ntohs(client->inaddr.sin_port));
printf("dst ip: [%s], port: [%d]\n", inet_ntoa(client->toaddr.sin_addr), ntohs(client->toaddr.sin_port));
*/
//printf("client len: %d\n", client->client_data_len);
//复制udp长度和原始目标地址
memcpy(client->client_data, &client->toaddr, sizeof(struct sockaddr_in));
memcpy(client->client_data + sizeof(struct sockaddr_in), &client->client_data_len, sizeof(uint16_t));
client->client_data_len += sizeof(uint16_t) + sizeof(struct sockaddr_in);
if (udp.encodeCode)
dataEncode(client->client_data, client->client_data_len, udp.encodeCode);
if (udp.httpsProxy_encodeCode)
dataEncode(client->client_data, client->client_data_len, udp.httpsProxy_encodeCode);
client->next = NULL;
return 0;
}
static void connectToServer(info_t * info)
{
info->timer = 0;
info->server_fd = socket(AF_INET, SOCK_STREAM, 0);
if (info->server_fd < 0)
return;
fcntl(info->server_fd, F_SETFL, O_NONBLOCK);
udp_ev.events = EPOLLIN | EPOLLOUT | EPOLLET;
udp_ev.data.ptr = info;
if (epoll_ctl(udp_efd, EPOLL_CTL_ADD, info->server_fd, &udp_ev) != 0) {
close(info->server_fd);
info->server_fd = -1;
} else if (connect(info->server_fd, (struct sockaddr *)&udp.dst, sizeof(udp.dst)) != 0 && errno != EINPROGRESS) {
epoll_ctl(udp_efd, EPOLL_CTL_DEL, info->server_fd, NULL);
close(info->server_fd);
info->server_fd = -1;
}
}
/* 源地址跟目标地址一样的话服务端需要同一个socket转发 */
static int margeClient(info_t * client)
{
int i;
for (i = 0; i < MAX_CLIENT_INFO; i++) {
if (client != client_info_list + i && client_info_list[i].server_fd > -1 && memcmp(((char *)&client->toaddr) + 2, ((char *)&client_info_list[i].toaddr) + 2, 6) == 0 && memcmp(((char *)&client->inaddr) + 2, ((char *)&client_info_list[i].inaddr) + 2, 6) == 0) {
info_t *lastInfo;
for (lastInfo = client_info_list + i; lastInfo->next; lastInfo = lastInfo->next) ;
lastInfo->next = client;
client->server_fd = -2; //保证下次调用margeClient()不匹配到这个结构体 并且不被其他客户端连接使用
client->client_data_sent_len = sizeof(struct sockaddr_in); //不再发送UDP目标地址
//没有收到服务端回应前不发送UDP的数据
if (client_info_list[i].http_request_sent_len > udp.http_request_len) {
udp_ev.events = EPOLLIN | EPOLLOUT | EPOLLET;
udp_ev.data.ptr = client_info_list + i;
epoll_ctl(udp_efd, EPOLL_CTL_MOD, client_info_list[i].server_fd, &udp_ev);
}
return 0;
}
}
return 1;
}
static void new_client()
{
int i;
for (i = 0; i < MAX_CLIENT_INFO; i++) {
if (client_info_list[i].server_fd == -1) {
if (recvClient(client_info_list + i) == 0)
if (margeClient(client_info_list + i) != 0)
connectToServer(client_info_list + i);
return;
}
}
}
static void http_udp_req_init()
{
char dest[22];
sprintf(dest, "%s:%u", inet_ntoa(udp.dst.sin_addr), ntohs(udp.dst.sin_port));
if (udp.http_request) {
udp.http_request_len = strlen(udp.http_request) + 2;
udp.http_request = (char *)realloc(udp.http_request, udp.http_request_len + 1);
if (udp.http_request == NULL)
errors("httpudp http request initializate failed.");
strcat(udp.http_request, "\r\n");
udp.http_request = replace(udp.http_request, &udp.http_request_len, "[V]", 3, "HTTP/1.1", 8);
udp.http_request = replace(udp.http_request, &udp.http_request_len, "[H]", 3, dest, strlen(dest));
udp.http_request = replace(udp.http_request, &udp.http_request_len, "\\0", 2, "\0", 1);
udp.http_request = replace(udp.http_request, &udp.http_request_len, "[M]", 3, "CONNECT", 7);
udp.http_request = replace(udp.http_request, &udp.http_request_len, "[url]", 5, "/", 1);
udp.http_request = replace(udp.http_request, &udp.http_request_len, "[U]", 3, "/", 1);
} else { /* 默认使用CONNECT请求 */
if (https.encodeCode) {
dataEncode(dest, strlen(dest), https.encodeCode);
udp.httpsProxy_encodeCode = https.encodeCode;
}
udp.http_request_len = default_ssl_request_len;
copy_new_mem(default_ssl_request, default_ssl_request_len, &udp.http_request);
udp.http_request = replace(udp.http_request, &udp.http_request_len, "[H]", 3, dest, strlen(dest));
memcpy(&udp.dst, &https.dst, sizeof(udp.dst));
}
if (udp.http_request == NULL)
errors("out of memory.");
/* 保存原始生成的请求头配合usr_hdr使用 */
if (saveHdrs) {
if (copy_new_mem(udp.http_request, udp.http_request_len, &udp.original_http_request) != 0)
errors("out of memory.");
udp.original_http_request_len = udp.http_request_len;
}
}
void udp_init()
{
int i;
//初始化http请求
http_udp_req_init();
//初始化结构体
memset(client_info_list, 0, sizeof(info_t) * MAX_CLIENT_INFO);
for (i = 0; i < MAX_CLIENT_INFO; i++)
client_info_list[i].server_fd = client_info_list[i].responseClientFd = -1;
//创建epoll fd
udp_efd = epoll_create(MAX_CLIENT_INFO * 2 + 1);
if (udp_efd < 0) {
perror("udp epoll_create()");
exit(1);
}
//添加监听socket到epoll
fcntl(global.udp_listen_fd, F_SETFL, O_NONBLOCK);
udp_ev.data.fd = global.udp_listen_fd;
udp_ev.events = EPOLLIN;
epoll_ctl(udp_efd, EPOLL_CTL_ADD, global.udp_listen_fd, &udp_ev);
}
void *udp_loop(void *nullPtr)
{
int n;
while (1) {
n = epoll_wait(udp_efd, udp_evs, MAX_CLIENT_INFO * 2 + 1, -1);
while (n-- > 0) {
if (udp_evs[n].data.fd == global.udp_listen_fd) {
new_client();
} else {
if (udp_evs[n].events & EPOLLIN) {
recvServer((info_t *) udp_evs[n].data.ptr);
}
if (udp_evs[n].events & EPOLLOUT) {
outEvent((info_t *) udp_evs[n].data.ptr);
}
}
}
}
return NULL; //消除编译警告
}