#include "sysutil.h"

int tcp_client(unsigned short port)
{
	int sock;
	if ((sock = socket(PF_INET, SOCK_STREAM, 0)) < 0)	//创建套接字
		ERR_EXIT("tcp_client");

	if (port > 0)
	{
		int on = 1;
		if ((setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (const char*)&on, sizeof(on))) < 0)
			ERR_EXIT("setsockopt");

		char ip[16] = {0};
		getlocalip(ip);		//获取服务器的地址
		struct sockaddr_in localaddr;
		memset(&localaddr, 0, sizeof(localaddr));
		localaddr.sin_family = AF_INET;
		localaddr.sin_port = htons(port);
		localaddr.sin_addr.s_addr = inet_addr(ip);
		if (bind(sock, (struct sockaddr*)&localaddr, sizeof(localaddr)) < 0)
			ERR_EXIT("bind");
	}

	return sock;
}

/**
 * tcp_server - 启动tcp服务器
 * @host: 服务器IP地址或者服务器主机名
 * @port: 服务器端口
 * 成功返回监听套接字
 */
int tcp_server(const char *host, unsigned short port)
{
	int listenfd;
	if ((listenfd = socket(PF_INET, SOCK_STREAM, 0)) < 0)	//socket(ipv4.tcp协议，0)
		ERR_EXIT("tcp_server");		//退出当前进程

	struct sockaddr_in servaddr;
	memset(&servaddr, 0, sizeof(servaddr));		//初始化为地址&servaddr为空
	/*
	void *memset(void *s, int ch, size_t n);
	函数解释：将s中当前位置后面的n个字节 （typedef unsigned int size_t ）用 ch 替换并返回 s 。
	memset：作用是在一段内存块中填充某个给定的值，它是对较大的结构体或数组进行清零操作的一种最快方法 [1]  。
	memset()函数原型是extern void *memset(void *buffer, int c, int count) buffer：为指针或是数组,c：是赋给buffer的值,count：是buffer的长度.
	*/
	servaddr.sin_family = AF_INET;
	if (host != NULL)
	{
		if (inet_aton(host, &servaddr.sin_addr) == 0)	
			/*将一个字符串IP地址转换为一个32位的网络序列IP地址
			int inet_aton(const char *string, struct in_addr*addr);
			参数描述：
			1 输入参数string包含ASCII表示的IP地址。
			2 输出参数addr是将要用新的IP地址更新的结构。*/
		{
			struct hostent *hp;
			hp = gethostbyname(host);	
			//gethostbyname()返回对应于给定主机名的包含主机名字和地址信息的hostent结构的指针。结构的声明与gethostbyaddr()中一致。
			if (hp == NULL)
				ERR_EXIT("gethostbyname");

			servaddr.sin_addr = *(struct in_addr*)hp->h_addr;	
		}
	}
	else
		servaddr.sin_addr.s_addr = htonl(INADDR_ANY);	//将主机数转换成无符号长整型的网络字节顺序。本函数将一个32位数从主机字节顺序转换成网络字节顺序。

	servaddr.sin_port = htons(port);	//htons是将整型变量从主机字节顺序转变成网络字节顺序， 就是整数在地址空间存储方式变为高位字节存放在内存的低地址处。

	int on = 1;
	if ((setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, (const char*)&on, sizeof(on))) < 0)		//防止重复套接字
		ERR_EXIT("setsockopt");

	if (bind(listenfd, (struct sockaddr*)&servaddr, sizeof(servaddr)) < 0)	//绑定套接字(绑定服务器端的IP的地址和端口号)
		ERR_EXIT("bind");

	if (listen(listenfd, SOMAXCONN) < 0)	//监听套接字(监控多少个客户端连接到该服务器)
		ERR_EXIT("listen");

	return listenfd;
}

/*需要修改 /etc/hosts-- 要不就换一种编程方式*/
int getlocalip(char *ip)
{
	char host[100] = {0};
	if (gethostname(host, sizeof(host)) < 0)	
		return -1;
	struct hostent *hp;
	if ((hp = gethostbyname(host)) == NULL)
	return -1;

	strcpy(ip, inet_ntoa(*(struct in_addr*)hp->h_addr));
	return 0;
}


/**
 * activate_noblock - 设置I/O为非阻塞模式
 * @fd: 文件描符符
 */
void activate_nonblock(int fd)
{
	int ret;
	int flags = fcntl(fd, F_GETFL);
	if (flags == -1)
		ERR_EXIT("fcntl");

	flags |= O_NONBLOCK;
	ret = fcntl(fd, F_SETFL, flags);
	if (ret == -1)
		ERR_EXIT("fcntl");
}

/**
 * deactivate_nonblock - 设置I/O为阻塞模式
 * @fd: 文件描符符
 */
void deactivate_nonblock(int fd)
{
	int ret;
	int flags = fcntl(fd, F_GETFL);
	if (flags == -1)
		ERR_EXIT("fcntl");

	flags &= ~O_NONBLOCK;
	ret = fcntl(fd, F_SETFL, flags);
	if (ret == -1)
		ERR_EXIT("fcntl");
}

/**
 * read_timeout - 读超时检测函数，不含读操作
 * @fd: 文件描述符
 * @wait_seconds: 等待超时秒数，如果为0表示不检测超时
 * 成功（未超时）返回0，失败返回-1，超时返回-1并且errno = ETIMEDOUT
 */
int read_timeout(int fd, unsigned int wait_seconds)
{
	int ret = 0;
	if (wait_seconds > 0)
	{
		fd_set read_fdset;
		struct timeval timeout;

		FD_ZERO(&read_fdset);
		FD_SET(fd, &read_fdset);

		timeout.tv_sec = wait_seconds;
		timeout.tv_usec = 0;
		do
		{
			ret = select(fd + 1, &read_fdset, NULL, NULL, &timeout);
		} while (ret < 0 && errno == EINTR);

		if (ret == 0)
		{
			ret = -1;
			errno = ETIMEDOUT;
		}
		else if (ret == 1)
			ret = 0;
	}

	return ret;
}

/**
 * write_timeout - 读超时检测函数，不含写操作
 * @fd: 文件描述符
 * @wait_seconds: 等待超时秒数，如果为0表示不检测超时
 * 成功（未超时）返回0，失败返回-1，超时返回-1并且errno = ETIMEDOUT
 */
int write_timeout(int fd, unsigned int wait_seconds)
{
	int ret = 0;
	if (wait_seconds > 0)
	{
		fd_set write_fdset;
		struct timeval timeout;

		FD_ZERO(&write_fdset);
		FD_SET(fd, &write_fdset);

		timeout.tv_sec = wait_seconds;
		timeout.tv_usec = 0;
		do
		{
			ret = select(fd + 1, NULL, NULL, &write_fdset, &timeout);
		} while (ret < 0 && errno == EINTR);

		if (ret == 0)
		{
			ret = -1;
			errno = ETIMEDOUT;
		}
		else if (ret == 1)
			ret = 0;
	}

	return ret;
}

/**
 * accept_timeout - 带超时的accept
 * @fd: 套接字
 * @addr: 输出参数，返回对方地址
 * @wait_seconds: 等待超时秒数，如果为0表示正常模式
 * 成功（未超时）返回已连接套接字，超时返回-1并且errno = ETIMEDOUT
 */
int accept_timeout(int fd, struct sockaddr_in *addr, unsigned int wait_seconds)
{
	int ret;
	socklen_t addrlen = sizeof(struct sockaddr_in);

	if (wait_seconds > 0)
	{
		fd_set accept_fdset;
		struct timeval timeout;
		FD_ZERO(&accept_fdset);
		FD_SET(fd, &accept_fdset);
		timeout.tv_sec = wait_seconds;
		timeout.tv_usec = 0;
		do
		{
			ret = select(fd + 1, &accept_fdset, NULL, NULL, &timeout);
		} while (ret < 0 && errno == EINTR);
		if (ret == -1)
			return -1;
		else if (ret == 0)
		{
			errno = ETIMEDOUT;
			return -1;
		}
	}

	if (addr != NULL)
		ret = accept(fd, (struct sockaddr*)addr, &addrlen);
	else
		ret = accept(fd, NULL, NULL);
/*	if (ret == -1)
		ERR_EXIT("accept");
		*/

	return ret;
}

/**
 * connect_timeout - connect
 * @fd: 套接字
 * @addr: 要连接的对方地址
 * @wait_seconds: 等待超时秒数，如果为0表示正常模式
 * 成功（未超时）返回0，失败返回-1，超时返回-1并且errno = ETIMEDOUT
 */
int connect_timeout(int fd, struct sockaddr_in *addr, unsigned int wait_seconds)
{
	int ret;
	socklen_t addrlen = sizeof(struct sockaddr_in);

	if (wait_seconds > 0)
		activate_nonblock(fd);

	ret = connect(fd, (struct sockaddr*)addr, addrlen);
	if (ret < 0 && errno == EINPROGRESS)
	{
		//printf("AAAAA\n");
		fd_set connect_fdset;
		struct timeval timeout;
		FD_ZERO(&connect_fdset);
		FD_SET(fd, &connect_fdset);
		timeout.tv_sec = wait_seconds;
		timeout.tv_usec = 0;
		do
		{
			/* 一量连接建立，套接字就可写 */
			ret = select(fd + 1, NULL, &connect_fdset, NULL, &timeout);
		} while (ret < 0 && errno == EINTR);
		if (ret == 0)
		{
			ret = -1;
			errno = ETIMEDOUT;
		}
		else if (ret < 0)
			return -1;
		else if (ret == 1)
		{
			//printf("BBBBB\n");
			/* ret返回为1，可能有两种情况，一种是连接建立成功，一种是套接字产生错误，*/
			/* 此时错误信息不会保存至errno变量中，因此，需要调用getsockopt来获取。 */
			int err;
			socklen_t socklen = sizeof(err);
			int sockoptret = getsockopt(fd, SOL_SOCKET, SO_ERROR, &err, &socklen);
			if (sockoptret == -1)
			{
				return -1;
			}
			if (err == 0)
			{
				//printf("DDDDDDD\n");
				ret = 0;
			}
			else
			{
				//printf("CCCCCC\n");
				errno = err;
				ret = -1;
			}
		}
	}
	if (wait_seconds > 0)
	{
		deactivate_nonblock(fd);
	}
	return ret;
}

/**
 * readn - 读取固定字节数
 * @fd: 文件描述符
 * @buf: 接收缓冲区
 * @count: 要读取的字节数
 * 成功返回count，失败返回-1，读到EOF返回<count
 */
ssize_t readn(int fd, void *buf, size_t count)
{
	size_t nleft = count;
	ssize_t nread;
	char *bufp = (char*)buf;

	while (nleft > 0)
	{
		if ((nread = read(fd, bufp, nleft)) < 0)
		{
			if (errno == EINTR)
				continue;
			return -1;
		}
		else if (nread == 0)
			return count - nleft;

		bufp += nread;
		nleft -= nread;
	}

	return count;
}

/**
 * writen - 发送固定字节数
 * @fd: 文件描述符
 * @buf: 发送缓冲区
 * @count: 要读取的字节数
 * 成功返回count，失败返回-1
 */
ssize_t writen(int fd, const void *buf, size_t count)
{
	size_t nleft = count;
	ssize_t nwritten;
	char *bufp = (char*)buf;

	while (nleft > 0)
	{
		if ((nwritten = write(fd, bufp, nleft)) < 0)
		{
			if (errno == EINTR)
				continue;
			return -1;
		}
		else if (nwritten == 0)
			continue;

		bufp += nwritten;
		nleft -= nwritten;
	}

	return count;
}

/**
 * recv_peek - 仅仅查看套接字缓冲区数据，但不移除数据
 * @sockfd: 套接字
 * @buf: 接收缓冲区
 * @len: 长度
 * 成功返回>=0，失败返回-1
 */
ssize_t recv_peek(int sockfd, void *buf, size_t len)
{
	while (1)
	{
		int ret = recv(sockfd, buf, len, MSG_PEEK);
		if (ret == -1 && errno == EINTR)
			continue;
		return ret;
	}
}

/**
 * readline - 按行读取数据
 * @sockfd: 套接字
 * @buf: 接收缓冲区
 * @maxline: 每行最大长度
 * 成功返回>=0，失败返回-1
 */
ssize_t readline(int sockfd, void *buf, size_t maxline)
{
	int ret;
	int nread;
	char *bufp = buf;
	int nleft = maxline;
	while (1)
	{
		ret = recv_peek(sockfd, bufp, nleft);
		if (ret < 0)
			return ret;
		else if (ret == 0)
			return ret;

		nread = ret;
		int i;
		for (i=0; i<nread; i++)
		{
			if (bufp[i] == '\n')
			{
				ret = readn(sockfd, bufp, i+1);
				if (ret != i+1)
					exit(EXIT_FAILURE);

				return ret;
			}
		}

		if (nread > nleft)
			exit(EXIT_FAILURE);

		nleft -= nread;
		ret = readn(sockfd, bufp, nread);
		if (ret != nread)
			exit(EXIT_FAILURE);

		bufp += nread;
	}

	return -1;
}

void send_fd(int sock_fd, int fd)
{
	int ret;
	struct msghdr msg;
	struct cmsghdr *p_cmsg;
	struct iovec vec;
	char cmsgbuf[CMSG_SPACE(sizeof(fd))];
	int *p_fds;
	char sendchar = 0;
	msg.msg_control = cmsgbuf;
	msg.msg_controllen = sizeof(cmsgbuf);
	p_cmsg = CMSG_FIRSTHDR(&msg);
	p_cmsg->cmsg_level = SOL_SOCKET;
	p_cmsg->cmsg_type = SCM_RIGHTS;
	p_cmsg->cmsg_len = CMSG_LEN(sizeof(fd));
	p_fds = (int*)CMSG_DATA(p_cmsg);
	*p_fds = fd;

	msg.msg_name = NULL;
	msg.msg_namelen = 0;
	msg.msg_iov = &vec;
	msg.msg_iovlen = 1;
	msg.msg_flags = 0;

	vec.iov_base = &sendchar;
	vec.iov_len = sizeof(sendchar);
	ret = sendmsg(sock_fd, &msg, 0);
	if (ret != 1)
		ERR_EXIT("sendmsg");
}

int recv_fd(const int sock_fd)
{
	int ret;
	struct msghdr msg;
	char recvchar;
	struct iovec vec;
	int recv_fd;
	char cmsgbuf[CMSG_SPACE(sizeof(recv_fd))];
	struct cmsghdr *p_cmsg;
	int *p_fd;
	vec.iov_base = &recvchar;
	vec.iov_len = sizeof(recvchar);
	msg.msg_name = NULL;
	msg.msg_namelen = 0;
	msg.msg_iov = &vec;
	msg.msg_iovlen = 1;
	msg.msg_control = cmsgbuf;
	msg.msg_controllen = sizeof(cmsgbuf);
	msg.msg_flags = 0;

	p_fd = (int*)CMSG_DATA(CMSG_FIRSTHDR(&msg));
	*p_fd = -1;  
	ret = recvmsg(sock_fd, &msg, 0);
	if (ret != 1)
		ERR_EXIT("recvmsg");

	p_cmsg = CMSG_FIRSTHDR(&msg);
	if (p_cmsg == NULL)
		ERR_EXIT("no passed fd");


	p_fd = (int*)CMSG_DATA(p_cmsg);
	recv_fd = *p_fd;
	if (recv_fd == -1)
		ERR_EXIT("no passed fd");

	return recv_fd;
}

const char* statbuf_get_perms(struct stat *sbuf)
{
	static char perms[] = "----------";
	perms[0] = '?';		//第一个参数代表文件类型

	mode_t mode = sbuf->st_mode;
	switch (mode & S_IFMT)	//文件类型:S_IFMT
	{
	case S_IFREG:	//普通文件
		perms[0] = '-';
		break;
	case S_IFDIR:	//目录文件
		perms[0] = 'd';
		break;
	case S_IFLNK:	//符号链接文件
		perms[0] = 'l';
		break;
	case S_IFIFO:	//管道文件
		perms[0] = 'p';
		break;
	case S_IFSOCK:	//套接字文件
		perms[0] = 's';
		break;
	case S_IFCHR:	//字符设备文件
		perms[0] = 'c';
		break;
	case S_IFBLK:	//块设备文件
		perms[0] = 'b';
		break;
	}
	/*权限位*/
	//owener权限--使用者
	if (mode & S_IRUSR)	//读权限
	{
		perms[1] = 'r';
	}
	if (mode & S_IWUSR)	//写权限
	{
		perms[2] = 'w';
	}
	if (mode & S_IXUSR)	//可执行权限
	{
		perms[3] = 'x';
	}
	//group权限--使用者所在组的成员
	if (mode & S_IRGRP)	//
	{
		perms[4] = 'r';
	}
	if (mode & S_IWGRP)
	{
		perms[5] = 'w';
	}
	if (mode & S_IXGRP)
	{
		perms[6] = 'x';
	}
	//其他用户权限--任何人
	if (mode & S_IROTH)
	{
		perms[7] = 'r';
	}
	if (mode & S_IWOTH)
	{
		perms[8] = 'w';
	}
	if (mode & S_IXOTH)
	{
		perms[9] = 'x';
	}
	//特殊权限
	if (mode & S_ISUID)
	{
		perms[3] = (perms[3] == 'x') ? 's' : 'S';
	}
	if (mode & S_ISGID)
	{
		perms[6] = (perms[6] == 'x') ? 's' : 'S';
	}
	if (mode & S_ISVTX)
	{
		perms[9] = (perms[9] == 'x') ? 't' : 'T';
	}

	return perms;
}

const char* statbuf_get_date(struct stat *sbuf)
{
	static char datebuf[64] = {0};
	const char *p_date_format = "%b %e %H:%M";	//一种时间格式
	struct timeval tv;
	gettimeofday(&tv, NULL);	//获取时间当前时间--获取到当前的时间并赋值到&tv，NULL表示当前时区
	time_t local_time = tv.tv_sec;
	if (sbuf->st_mtime > local_time || (local_time - sbuf->st_mtime) > 60*60*24*182)
	{
		p_date_format = "%b %e  %Y";
	}

	struct tm* p_tm = localtime(&local_time);	//秒转化成结构体类型
	strftime(datebuf, sizeof(datebuf), p_date_format, p_tm);	//格式化时间--将p_tm这个时间结构体采用p_date_format格式格式化

	return datebuf;
}

static int lock_internal(int fd, int lock_type)
{
	int ret;
	struct flock the_lock;
	memset(&the_lock, 0, sizeof(the_lock));
	the_lock.l_type = lock_type;
	the_lock.l_whence = SEEK_SET;
	the_lock.l_start = 0;
	the_lock.l_len = 0;
	do
	{
		ret = fcntl(fd, F_SETLKW, &the_lock);
	}
	while (ret < 0 && errno == EINTR);

	return ret;
}

int lock_file_read(int fd)
{
	return lock_internal(fd, F_RDLCK);	
}


int lock_file_write(int fd)
{
	return lock_internal(fd, F_WRLCK);
}


int unlock_file(int fd)
{
	int ret;
	struct flock the_lock;
	memset(&the_lock, 0, sizeof(the_lock));
	the_lock.l_type = F_UNLCK;
	the_lock.l_whence = SEEK_SET;
	the_lock.l_start = 0;
	the_lock.l_len = 0;

	ret = fcntl(fd, F_SETLK, &the_lock);

	return ret;
}

static struct timeval s_curr_time;
long get_time_sec(void)
{
	if (gettimeofday(&s_curr_time, NULL) < 0)	//获取时间或时区
	{
		ERR_EXIT("gettimeofday");
	}

	return s_curr_time.tv_sec;	//返回秒
}

long get_time_usec(void)
{
	/*
	struct timeval curr_time;
	if (gettimeofday(&curr_time, NULL) < 0)
	{
		ERR_EXIT("gettimeofday");
	}

	return curr_time.tv_usec;
	*/
	return s_curr_time.tv_usec;	//返回微秒
}

void nano_sleep(double seconds)
{
	time_t secs = (time_t)seconds;					// 整数部分
	double fractional = seconds - (double)secs;		// 小数部分

	struct timespec ts;
	ts.tv_sec = secs;	//秒
	ts.tv_nsec = (long)(fractional * (double)1000000000);	//纳秒
	
	int ret;
	do
	{
		ret = nanosleep(&ts, &ts);		//这个函数功能是暂停某个进程直到你规定的时间后恢复
	}
	while (ret == -1 && errno == EINTR);
}

// 开启套接字fd接收带外数据的功能
void activate_oobinline(int fd)
{
	int oob_inline = 1;
	int ret;
	ret = setsockopt(fd, SOL_SOCKET, SO_OOBINLINE, &oob_inline, sizeof(oob_inline));
	if (ret == -1)
	{
		ERR_EXIT("setsockopt");
	}
}

// 当文件描述fd上有带外数据的时候，将产生SIGURG信号，
// 该函数设定当前进程能够接收fd文件描述符所产生的SIGURG信号
void activate_sigurg(int fd)
{
	int ret;
	ret = fcntl(fd, F_SETOWN, getpid());
	if (ret == -1)
	{
		ERR_EXIT("fcntl");
	}
}



int get_local_ip(char* ip)
{
	int sd;
	struct sockaddr_in sin;
	struct ifreq ifr;

	sd = socket(AF_INET, SOCK_DGRAM, 0);
	if (-1 == sd)
	{
		printf("socket error: %s\n", strerror(errno));
		return -1;
	}

	strncpy(ifr.ifr_name, eth, IFNAMSIZ);
	ifr.ifr_name[IFNAMSIZ - 1] = 0;

	// if error: No such device
	if (ioctl(sd, SIOCGIFADDR, &ifr) < 0)
	{
		printf("ioctl error: %s\n", strerror(errno));
		close(sd);
		return -1;
	}

	memcpy(&sin, &ifr.ifr_addr, sizeof(sin));
	snprintf(ip, IP_SIZE, "%s", inet_ntoa(sin.sin_addr));

	close(sd);
	return 0;
}