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我想提高数据包发送性能。在此之前,我使用原始套接字,现在我学习packet_mmap。 我有数据包(帧),我已经从另一台PC的内核模块捕获,放到当前的PC,现在我想重发他们到本地接口与转发。 我有例子packet_mmap的,它集成到我的项目,但我送数据包mmap发送数据包格式
fd_socket = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
memset(&my_addr, 0, sizeof(struct sockaddr_ll));
my_addr.sll_family = PF_PACKET;
my_addr.sll_protocol = htons(ETH_P_ALL);
strcpy(str_devname, "eth0");
strncpy(s_ifr.ifr_name, str_devname, sizeof(s_ifr.ifr_name));
ec = ioctl(fd_socket, SIOCGIFINDEX, &s_ifr);
i_ifindex = s_ifr.ifr_ifindex;
memset(&my_addr, 0, sizeof(struct sockaddr_ll));
my_addr.sll_family = AF_PACKET;
my_addr.sll_protocol = ETH_P_ALL;
my_addr.sll_ifindex = i_ifindex;
bind(fd_socket, (struct sockaddr *) &my_addr, sizeof(struct sockaddr_ll)
s_packet_req.tp_block_size = c_buffer_sz;
s_packet_req.tp_frame_size = c_buffer_sz;
s_packet_req.tp_block_nr = c_buffer_nb;
s_packet_req.tp_frame_nr = c_buffer_nb;
size = s_packet_req.tp_block_size * s_packet_req.tp_block_nr;
if (setsockopt(fd_socket, SOL_PACKET, PACKET_TX_RING, (char *) &s_packet_req, sizeof(s_packet_req)) < 0) {
perror("setsockopt: PACKET_TX_RING");
return;
}
if (c_sndbuf_sz) {
printf("send buff size = %d\n", c_sndbuf_sz);
if (setsockopt(fd_socket, SOL_SOCKET, SO_SNDBUF, &c_sndbuf_sz, sizeof(c_sndbuf_sz)) < 0){
perror("getsockopt: SO_SNDBUF");
exit(1);
}
}
data_offset = TPACKET_HDRLEN - sizeof(struct sockaddr_ll);
printf("data offset = %d bytes\n", data_offset);
ps_header_start = (tpacket_hdr *) mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd_socket, 0);
if (ps_header_start == (void*) -1) {
perror("mmap");
exit(1);
}
然后,我填写的数据
ps_header = ((struct tpacket_hdr *) ((char *) ps_header_start + (c_buffer_sz * i_index)));
if (!ps_header) {
perror("ps_header") ;
return NULL;
}
data = ((char*) ps_header) + data_offset;
switch ((volatile uint32_t) ps_header->tp_status) {
case TP_STATUS_AVAILABLE:
printf("TP_STATUS_AVAILABLE, index=%d\n",i_index) ;
memcpy(data, packet_data, size);
pthread_mutex_lock(&index_locker) ;
i_index++;
pthread_mutex_unlock(&index_locker) ;
if (i_index >= c_buffer_nb) {
i_index = 0;
first_loop = 0;
}
/* update packet len */
ps_header->tp_len = size;
/* set header flag to USER (trigs xmit)*/
ps_header->tp_status = TP_STATUS_SEND_REQUEST;
然后我送
ec_send = sendto(fd_socket, NULL, 0, 0, (struct sockaddr *) ps_sockaddr, sizeof(struct sockaddr_ll));
我有没有错误,ec_send =不是发送数据的大小。但没有数据路由到目标主机。
所以,我问 - 什么数据我应该传递到环形缓冲区,现在我包含头IP,TCP,我应该包括MAC头? - 可能是我必须设置额外的标志来路由我的数据包。
现在我可以使用tshark查看由我发送的数据包......但是它们无法到达目的地......我查看ping应答,但ping程序没有收到数据包。我不知道我应该用什么接口传输,真实还是本地? – SeregASM
嗨,我可以得到您正在使用的示例应用程序使用PACKET_MMAP从用户空间发送数据包 – codingfreak