标签：-- mission socket编程 color number tag for reserve use
在socket网络编程中经常用到一些宏定义、结构和函数，这些经常包含在相关的头文件中，使用时直接include相关头文件即可。下面简单描述下相关的一些结构及头文件。
1. sockaddr / bits/socket.h
socket编程最基本的就是socket地址，其定义在bits/socket.h中。但sys/socket.h包含bits/socket.h，且bits/socket.h明确指出该头文件不能直接使用，应使用sys/socket.h代替。
struct sockaddr { __SOCKADDR_COMMON (sa_); /* Common data: address family and length. */ char sa_data[14]; /* Address data. */ };
其中__SOCKADDR_COMMON()宏定义在bits/sockaddr.h中
#define __SOCKADDR_COMMON(sa_prefix) \ sa_family_t sa_prefix##family #define __SOCKADDR_COMMON_SIZE (sizeof (unsigned short int))
替换后为
struct sockaddr{ unsigned short sa_family; char sa_data[14]; };
在bits/socket.h中还定义了协议族（Protocol families，PF_xxx）和地址族（Address families，AF_xx），两者一一对应，因此可以互换，应用场合根据概念稍有不同。
#define PF_UNSPEC 0 /* Unspecified. */ #define PF_LOCAL 1 /* Local to host (pipes and file-domain). */ #define PF_UNIX PF_LOCAL /* POSIX name for PF_LOCAL. */ #define PF_FILE PF_LOCAL /* Another non-standard name for PF_LOCAL. */ #define PF_INET 2 /* IP protocol family. */ #define PF_AX25 3 /* Amateur Radio AX.25. */ #define PF_IPX 4 /* Novell Internet Protocol. */ #define PF_APPLETALK 5 /* Appletalk DDP. */ #define PF_INET6 10 /* IP version 6. */ #define PF_LLC 26 /* Linux LLC. */ #define PF_CAN 29 /* Controller Area Network. */ #define PF_NFC 39 /* NFC sockets. */ #define PF_VSOCK 40 /* vSockets. */ #define PF_MAX 41 /* For now.. */
2. sys/socket.h
该头文件包含常用的socket编程函数接口，如：
socket() bind() listen() connect() accept() shutdown()
send() recv() sendto() recvfrom() sendmsg() recvmsg() sendmmsg() recvmmsg()
socketpair() getsockname() getpeername()
getsockopt() setsockopt()
除此外，sys/socket.h包含bits/socket.h，需要bits/socket.h的函数直接include sys/socket.h即可。
3. 网络socket地址 sockaddr_in -- netinet/in.h
与internet网络相关的头文件大部分在netinet目录下，如in.h ip.h tcp.h udp.h ip_icmp.h ip6.h icmp6.h等。
在网络编程中用到的socket地址是经过转换的网络socket地址sockaddr_in:
/* Structure describing an Internet socket address. */ struct sockaddr_in { __SOCKADDR_COMMON (sin_); /* unsigned short sin_family; */ in_port_t sin_port; /* Port number. */ struct in_addr sin_addr; /* Internet address. */ /* Pad to size of `struct sockaddr‘. */ unsigned char sin_zero[sizeof (struct sockaddr) - __SOCKADDR_COMMON_SIZE - sizeof (in_port_t) - sizeof (struct in_addr)]; };
网络地址
/* Internet address. */ typedef uint32_t in_addr_t; struct in_addr { in_addr_t s_addr; };
网络端口
/* Type to represent a port. */ typedef uint16_t in_port_t;
netinet/in.h定义了标准协议enum：
enum { IPPROTO_IP = 0, /* Dummy protocol for TCP. */ #define IPPROTO_IP IPPROTO_IP IPPROTO_ICMP = 1, /* Internet Control Message Protocol. */ #define IPPROTO_ICMP IPPROTO_ICMP IPPROTO_IGMP = 2, /* Internet Group Management Protocol. */ #define IPPROTO_IGMP IPPROTO_IGMP IPPROTO_IPIP = 4, /* IPIP tunnels (older KA9Q tunnels use 94). */ #define IPPROTO_IPIP IPPROTO_IPIP IPPROTO_TCP = 6, /* Transmission Control Protocol. */ #define IPPROTO_TCP IPPROTO_TCP IPPROTO_EGP = 8, /* Exterior Gateway Protocol. */ #define IPPROTO_EGP IPPROTO_EGP IPPROTO_PUP = 12, /* PUP protocol. */ #define IPPROTO_PUP IPPROTO_PUP IPPROTO_UDP = 17, /* User Datagram Protocol. */ #define IPPROTO_UDP IPPROTO_UDP IPPROTO_IDP = 22, /* XNS IDP protocol. */ IPPROTO_IPV6 = 41, /* IPv6 header. */
#define IPPROTO_IPV6 IPPROTO_IPV6
IPPROTO_RAW = 255, /* Raw IP packets. */
#define IPPROTO_RAW IPPROTO_RAW
IPPROTO_MAX }；
标准端口enum
enum { IPPORT_ECHO = 7, /* Echo service. */ IPPORT_DISCARD = 9, /* Discard transmissions service. */ IPPORT_SYSTAT = 11, /* System status service. */ IPPORT_DAYTIME = 13, /* Time of day service. */ IPPORT_NETSTAT = 15, /* Network status service. */ IPPORT_FTP = 21, /* File Transfer Protocol. */ IPPORT_TELNET = 23, /* Telnet protocol. */ IPPORT_SMTP = 25, /* Simple Mail Transfer Protocol. */ IPPORT_TIMESERVER = 37, /* Timeserver service. */ IPPORT_NAMESERVER = 42, /* Domain Name Service. */ IPPORT_WHOIS = 43, /* Internet Whois service. */ IPPORT_MTP = 57, IPPORT_TFTP = 69, /* Trivial File Transfer Protocol. */ IPPORT_RJE = 77, IPPORT_FINGER = 79, /* Finger service. */ IPPORT_TTYLINK = 87, IPPORT_SUPDUP = 95, /* SUPDUP protocol. */ IPPORT_EXECSERVER = 512, /* execd service. */ IPPORT_LOGINSERVER = 513, /* rlogind service. */ IPPORT_CMDSERVER = 514, IPPORT_EFSSERVER = 520, /* UDP ports. */ IPPORT_BIFFUDP = 512, IPPORT_WHOSERVER = 513, IPPORT_ROUTESERVER = 520, /* Ports less than this value are reserved for privileged processes. */ IPPORT_RESERVED = 1024, /* Ports greater this value are reserved for (non-privileged) servers. */ IPPORT_USERRESERVED = 5000 };
标签：-- mission socket编程 color number tag for reserve use
原文地址：http://www.cnblogs.com/embedded-linux/p/7073932.html
