《UNIX环境高级编程》——读书笔记16

16 网络IPC：套接字

16.1 引言

    管道、先进先出、消息队列、信号量及共享内存

16.2 套接字描述符

#include <sys/socket.h>

int socket( int domain, int type, int protocol );

domain: AF_INET, AF_INET6, AF_UNIX, AF_UNSPEC  AF: address family

type: SOCK_DGRAM, SOCK_RAW, SOCK_SEQPACKET, SOCK_STREAM

protocol： 0

int shutdown( int sockfd, int how );

16.3 寻址

16.3.1 字节序

#include <arpa/inet.h>

uint32_t htonl( uint32_t hostint32 );

uint16_t htons( uint16_t hostint16 );

uint32_t ntohl( uint32_t netint32 );

uint16_t ntohs( uint16_t netint16 );

16.3.2 地址格式

struct sockaddr{

  sa_family_t sa_family;

  char             sa_data[14];

};

struct sockaddr_in{

  sa_family_t      sin_family;

  in_port_t           sin_port;

  struct in_addr  sin_addr;

  unsigned char sin_zero[8];

};

#include <arpa/inet.h>

const char *inet_ntop( int domain, const void * restrict addr, char *restrict str, socklen_t size );

int *inet_pton( int domain, const char *restrict str, void * restrict addr );

16.3.3 地址查询

#include <netdb.h>

struct hostent *gethostent( void );

void sethostent( int stayopen );

void endhostent( void );

struct hostent{

  char *h_name;

  char **aliases;

  int     h_addrtype;

  int     h_length;

  char **h_addr_list;

};

#include <netdb.h>

struct netent *getnetbyaddr( uint32_t net, int type );

struct netent *getnetbyname( const char *name );

struct netent *getnetent( void );

void setnetent( int stayopen );

void endnetent( void );

struct netent{

  char *n_name;

  char **n_aliases;

  int     n_addrtype;

  uint32_t n_net;

...

};

struct protoent *getprotobyname( const char *name );

struct protoent *getprotobynumber( int proto );

struct protoent *getprotoent( void );

void setprotoent( int stayopen );

void endprotoent( void );

struct protoent{

  char *p_name;

  char **p_aliases;

  int     p_proto;

...

};

struct netent *getservbyname( const char *name, const char *proto );

struct netent *getservbyport( int port, const char *proto );

struct netent *getservent( void );

void setservent( int stayopen );

void endservent( void );

struct netent{

  char *s_name;

  char **s_aliases;

  int     s_port;

  char *s_proto;

...

};

#include <sys/socket.h>

#include <netdb.h>

int getaddrinfo( const char *restrict host, const char *restrict service, const struct addrinfo *restrict hint, struct addrinfo **restrict res );

void freeaddrinfo( struct addrinfo *ai );

struct addrinfo{

  int        ai_flags;

  int        ai_family;

  int        ai_socktype;

  int        ai_protocol;

  socklen_t   ai_addrlen;

  struct sockaddr *ai_addr; 

  char     *ai_canoname; 

  struct addrinfo  *ai_next;

  ...

};

#include <netdb.h>

const char *gai_strerror( int error );

#include <sys/socket.h>

#include <netdb.h>

int getnameinfo( const struct sockaddr *restrict addr,

                               socklen_t alen, char *restrict host, 

                               socklen_t hostlen, char (restrict service,

                               socklen_t servlen, unsigned int flags );

16.3.4 将套接字与地址绑定

#include <sys/socket.h>

int bind( int sockfd, const struct sockaddr *addr, socklen_t len );

int getsockname( int sockfd, struct sockaddr *restrict addr, socklen_t *restrict alenp );

int getpeername( int sockfd, struct sockaddr *restrict addr, socklen_t *restrict alenp );

16.4 建立连接

#include <sys/socket.h>

int connect( int sockfd, const struct sockaddr *addr, socklen_t len );

int listen( int sockfd, int backlog );

int accept( int sockfd, struct sockaddr *restrict addr, socklen_t *restrict len );

16.5 数据传输

#include <sys/socket.h>

ssize_t send( int sockfd, const void *buf, size_t nbytes, int flags );

ssizt_t sendto( int sockfd, const void *buf, size_t nbytes, int flags, const struct sockaddr *destaddr, socklen_t destlen );

ssize_t sendmsg( int sockfd, const struct msgdr *msg, int flags );

ssize_t recvfrom( int sockfd, void *restrict buf, size_t len, int flags, struct sockaddr *restrict addr, socklen_t *restrict addrlen );

ssize_t recvmsg( int sockfd, struct msghdr *msg, int flags );

16.6 套接字选项

#include <sys/socket.h>

int setsockopt( int sockfd, int level, int option, const void *val, socklen_t len );

int getsockopt( int sockfd, int level, int option, void *restrict val, socklen_t *restrict lenp );

16.7 带外数据

#include <sys/socket.h>

int sockatmark( int sockfd );

16.8 非阻塞和异步I/O