The price of bitcoin in 2013
The remitter pays bitcoin directly to the recipient's address through a computer or smart phone
bitcoin transaction data is packaged into a "data block" or "block", and the transaction is initially confirmed. When the block is connected to the previous block, the transaction will be further confirmed. After six successive large amount confirmations, this transaction has basically been irreversibly confirmed
bitcoin peer-to-peer network stores all its transaction history in the "blockchain". The blockchain continues to grow, and once new blocks are added to the blockchain, they can no longer be deleted. Blockchain is actually a distributed database, which is composed of a group of scattered customer nodes and all participants. It records the history of all bitcoin transactions
{rrrrrrr}
extended data:
users can buy bitcoin, and then use computers to do a lot of calculations to "mine" them. When users "dig" bitcoin, the computer will search for 64 digit numbers, and then compete with other gold diggers to repeatedly solve the puzzle and provide the number needed by the bitcoin network. If the user's computer successfully creates a set of numbers, it will get 25 bitcoins
From 2012 to 2014, bitcoin swept the world, graally forming a "virtual currency" instry chain represented by bitcoin. This is a reform of the financial instry and a new proct of the combination of the financial instry and the Internet. It represents a financial milestone in the new era and opens a new chapter in the history of the Internet. Bitcoin fund is one of the derivatives represented by bitcoin in the era of "virtual currency" FXCM China said bitcoin fund will open in autumn 2014. FXCM bitcoin fund, as the world's first mutually beneficial and win-win financial model, has a new look, but it is also full of temptations and challengesaccording to the data of coindesk digital currency trading platform, the price of bitcoin once fell below US $6000 in 18 years, which has dropped by 70% compared with the highest value of US $20000 in 2017
"the price movements we are seeing now may seem drastic, but they are quite normal for this market." Etiro's senior market analyst, MATI Greenspan, wrote in an email to CNBC
with the decline of bitcoin, most digital currencies are affected, and other digital currencies are not much better. Most digital currencies are down by more than 10%. But in the long run, the future of digital currency is worth looking forward to.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <netdb.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/ip.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <netpacket/packet.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <arpa/inet.h>
#include <errno.h>
/* 接收缓冲区大小 */
#define RCV_BUF_SIZE 1024 * 5
/* 接收缓冲区 */
static int g_iRecvBufSize = RCV_BUF_SIZE;
static char g_acRecvBuf[RCV_BUF_SIZE] = {0};
/* 物理网卡接口,需要根据具体情况修改 */
static const char *g_szIfName = "eth1";
/* 以太网帧封装的协议类型 */
static const int g_iEthProId[] = { ETHERTYPE_PUP,
ETHERTYPE_SPRITE,
ETHERTYPE_IP,
ETHERTYPE_ARP,
ETHERTYPE_REVARP,
ETHERTYPE_AT,
ETHERTYPE_AARP,
ETHERTYPE_VLAN,
ETHERTYPE_IPX,
ETHERTYPE_IPV6,
ETHERTYPE_LOOPBACK
};
static const char g_szProName[][24] = {
"none", "xerox pup", "sprite", "ip", "arp",
"rarp", "apple-protocol", "apple-arp",
"802.1q", "ipx", "ipv6", "loopback"
};
/* 输出MAC地址 */
static void ethmp_showMac(const int iType, const char acHWAddr[])
{ int i = 0;
if (0 == iType)
{
printf("SMAC=[");
}
else
{
printf("DMAC=[");
}
for(i = 0; i < ETHER_ADDR_LEN - 1; i++)
{
printf("%02x:", *((unsigned char *)&(acHWAddr[i])));
}
printf("%02x] ", *((unsigned char *)&(acHWAddr[i])));
}
/* 物理网卡混杂模式属性操作 */
static int ethmp_setPromisc(const char *pcIfName, int fd, int iFlags)
{ int iRet = -1;
struct ifreq stIfr;
/* 获取接口属性标志位 */
strcpy(stIfr.ifr_name, pcIfName);
iRet = ioctl(fd, SIOCGIFFLAGS, &stIfr);
if (0 > iRet)
{ perror("[Error]Get Interface Flags");
return -1;
}
if (0 == iFlags)
{ /* 取消混杂模式 */
stIfr.ifr_flags &= ~IFF_PROMISC;
}
else
{ /* 设置为混杂模式 */
stIfr.ifr_flags |= IFF_PROMISC;
}
iRet = ioctl(fd, SIOCSIFFLAGS, &stIfr);
if (0 > iRet)
{ perror("[Error]Set Interface Flags");
return -1;
}
return 0;
}
/* 获取L2帧封装的协议类型 */
static char *ethmp_getProName(const int iProNum)
{ int iIndex = 0;
for(iIndex = 0; iIndex < sizeof(g_iEthProId) / sizeof(g_iEthProId[0]); iIndex++)
{ if (iProNum == g_iEthProId[iIndex])
{
break;
}
}
return (char *)(g_szProName[iIndex + 1]);
}
/* Init L2 Socket */
static int ethmp_initSocket()
{ int iRet = -1;
int fd = -1;
struct ifreq stIf;
struct sockaddr_ll stLocal = {0};
/* 创建SOCKET */
fd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
if (0 > fd)
{ perror("[Error]Initinate L2 raw socket");
return -1;
}
/* 网卡混杂模式设置 */
ethmp_setPromisc(g_szIfName, fd, 1);
/* 设置SOCKET选项 */
iRet = setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &g_iRecvBufSize,sizeof(int));
if (0 > iRet)
{ perror("[Error]Set socket option");
close(fd);
return -1;
}
/* 获取物理网卡接口索引 */
strcpy(stIf.ifr_name, g_szIfName);
iRet = ioctl(fd, SIOCGIFINDEX, &stIf);
if (0 > iRet)
{ perror("[Error]Ioctl operation");
close(fd);
return -1;
}
/* 绑定物理网卡 */
stLocal.sll_family = PF_PACKET;
stLocal.sll_ifindex = stIf.ifr_ifindex;
stLocal.sll_protocol = htons(ETH_P_ALL);
iRet = bind(fd, (struct sockaddr *)&stLocal, sizeof(stLocal));
if (0 > iRet)
{ perror("[Error]Bind the interface");
close(fd);
return -1;
}
return fd;
}
/* 解析Ethernet帧首部 */
static int ethmp_parseEthHead(const struct ether_header *pstEthHead)
{ unsigned short usEthPktType;
if (NULL == pstEthHead)
{ return -1;}
/* 协议类型、源MAC、目的MAC */
usEthPktType = ntohs(pstEthHead->ether_type);
printf(">>>\nEth-Pkt-Type:0x%04x(%s) ", usEthPktType, ethmp_getProName(usEthPktType));
ethmp_showMac(0, pstEthHead->ether_shost);
ethmp_showMac(1, pstEthHead->ether_dhost);
return 0;
}
/* 解析IP数据包头 */
static int ethmp_parseIpHead(const struct ip *pstIpHead)
{ struct protoent *pstIpProto = NULL;
if (NULL == pstIpHead)
{ return -1;}
/* 协议类型、源IP地址、目的IP地址 */
pstIpProto = getprotobynumber(pstIpHead->ip_p);
if(NULL != pstIpProto)
{ printf("\nIP-Pkt-Type:%d(%s) ", pstIpHead->ip_p, pstIpProto->p_name); }
else
{ printf("\nIP-Pkt-Type:%d(%s) ", pstIpHead->ip_p, "None");}
printf("SAddr=[%s] ", inet_ntoa(pstIpHead->ip_src));
printf("DAddr=[%s]\n", inet_ntoa(pstIpHead->ip_dst));
return 0;
}
/* 数据帧解析函数 */
static int ethmp_parseFrame(const char *pcFrameData)
{ int iRet = -1;
struct ether_header *pstEthHead = NULL;
struct ip *pstIpHead = NULL;
/* Ethnet帧头解析 */
pstEthHead = (struct ether_header*)g_acRecvBuf;
iRet = ethmp_parseEthHead(pstEthHead);
if (0 > iRet)
{ return iRet;}
/* IP数据包类型 */
pstIpHead = (struct ip *)(pstEthHead + 1);
iRet = ethmp_parseIpHead(pstIpHead);
return iRet;
}
/* 捕获网卡数据帧 */
static void ethmp_startCapture(const int fd)
{ int iRet = -1;
socklen_t stFromLen = 0;
/* 循环监听 */
while(1)
{ /* 清空接收缓冲区 */
memset(g_acRecvBuf, 0, RCV_BUF_SIZE);
/* 接收数据帧 */
iRet = recvfrom(fd, g_acRecvBuf, g_iRecvBufSize, 0, NULL, &stFromLen);
if (0 > iRet)
{ continue;}
/* 解析数据帧 */
ethmp_parseFrame(g_acRecvBuf);
}
}
/* Main */
int main(int argc, char *argv[])
{ int iRet = -1;
int fd = -1;
/* 初始化SOCKET */
fd = ethmp_initSocket();
if(0 > fd) {
return -1;
}
/* 捕获数据包 */
ethmp_startCapture(fd);
/* 关闭SOCKET */
close(fd);
return 0;
}
编译命令
gcc -o a a.c
./a
实现效果图
...
>>>Eth-Pkt-Type:0x0800(ip) SMAC=[00:1a:92:ef:b6:dd] DMAC=[00:24:7e:dc:99:18] IP-Pkt-Type:6(tcp) SAddr=[192.168.0.111] DAddr=[192.168.0.100]
>>> Eth-Pkt-Type:0x0800(ip) SMAC=[00:24:7e:dc:99:18] DMAC=[00:1a:92:ef:b6:dd] IP-Pkt-Type:6(tcp) SAddr=[192.168.0.100] DAddr=[192.168.0.111]
>>> Eth-Pkt-Type:0x0800(ip) SMAC=[00:24:7e:dc:99:18] DMAC=[00:1a:92:ef:b6:dd] IP-Pkt-Type:1(icmp) SAddr=[192.168.0.100] DAddr=[192.168.0.111]
>>> Eth-Pkt-Type:0x0800(ip) SMAC=[00:1a:92:ef:b6:dd] DMAC=[00:24:7e:dc:99:18] IP-Pkt-Type:1(icmp) SAddr=[192.168.0.111] DAddr=[192.168.0.100]
>>> Eth-Pkt-Type:0x0800(ip) SMAC=[00:1a:92:ef:b6:dd] DMAC=[00:24:7e:dc:99:18] IP-Pkt-Type:6(tcp) SAddr=[192.168.0.111] DAddr=[192.168.0.100]
...