Saturday, June 13, 2015
#include <sys/types.h> /* See NOTES */
#include <sys/socket.h>
int socket(int domain, int type, int protocol);
1. Domain (Address Families or Protocol Families)
#include <linux/socket.h>
#define AF_UNSPEC 0
#define AF_UNIX 1 /* Unix domain sockets */
#define AF_LOCAL 1 /* POSIX name for AF_UNIX */
#define AF_INET 2 /* Internet IP Protocol */
#define AF_AX25 3 /* Amateur Radio AX.25 */
#define AF_IPX 4 /* Novell IPX */
#define AF_APPLETALK 5 /* AppleTalk DDP */
#define AF_NETROM 6 /* Amateur Radio NET/ROM */
#define AF_BRIDGE 7 /* Multiprotocol bridge */
#define AF_ATMPVC 8 /* ATM PVCs */
#define AF_X25 9 /* Reserved for X.25 project */
#define AF_INET6 10 /* IP version 6 */
#define AF_ROSE 11 /* Amateur Radio X.25 PLP */
#define AF_DECnet 12 /* Reserved for DECnet project */
#define AF_NETBEUI 13 /* Reserved for 802.2LLC project*/
#define AF_SECURITY 14 /* Security callback pseudo AF */
#define AF_KEY 15 /* PF_KEY key management API */
#define AF_NETLINK 16
#define AF_ROUTE AF_NETLINK /* Alias to emulate 4.4BSD */
#define AF_PACKET 17 /* Packet family */
#define AF_ASH 18 /* Ash */
#define AF_ECONET 19 /* Acorn Econet */
#define AF_ATMSVC 20 /* ATM SVCs */
#define AF_RDS 21 /* RDS sockets */
#define AF_SNA 22 /* Linux SNA Project (nutters!) */
#define AF_IRDA 23 /* IRDA sockets */
#define AF_PPPOX 24 /* PPPoX sockets */
#define AF_WANPIPE 25 /* Wanpipe API Sockets */
#define AF_LLC 26 /* Linux LLC */
#define AF_CAN 29 /* Controller Area Network */
#define AF_TIPC 30 /* TIPC sockets */
#define AF_BLUETOOTH 31 /* Bluetooth sockets */
#define AF_IUCV 32 /* IUCV sockets */
#define AF_RXRPC 33 /* RxRPC sockets */
#define AF_ISDN 34 /* mISDN sockets */
#define AF_PHONET 35 /* Phonet sockets */
#define AF_IEEE802154 36 /* IEEE802154 sockets */
#define AF_MAX 37 /* For now.. */
/* Protocol families, same as address families. */
#define PF_UNSPEC AF_UNSPEC
#define PF_UNIX AF_UNIX
#define PF_LOCAL AF_LOCAL
#define PF_INET AF_INET
#define PF_AX25 AF_AX25
#define PF_IPX AF_IPX
#define PF_APPLETALK AF_APPLETALK
#define PF_NETROM AF_NETROM
#define PF_BRIDGE AF_BRIDGE
#define PF_ATMPVC AF_ATMPVC
#define PF_X25 AF_X25
#define PF_INET6 AF_INET6
#define PF_ROSE AF_ROSE
#define PF_DECnet AF_DECnet
#define PF_NETBEUI AF_NETBEUI
#define PF_SECURITY AF_SECURITY
#define PF_KEY AF_KEY
#define PF_NETLINK AF_NETLINK
#define PF_ROUTE AF_ROUTE
#define PF_PACKET AF_PACKET
#define PF_ASH AF_ASH
#define PF_ECONET AF_ECONET
#define PF_ATMSVC AF_ATMSVC
#define PF_RDS AF_RDS
#define PF_SNA AF_SNA
#define PF_IRDA AF_IRDA
#define PF_PPPOX AF_PPPOX
#define PF_WANPIPE AF_WANPIPE
#define PF_LLC AF_LLC
#define PF_CAN AF_CAN
#define PF_TIPC AF_TIPC
#define PF_BLUETOOTH AF_BLUETOOTH
#define PF_IUCV AF_IUCV
#define PF_RXRPC AF_RXRPC
#define PF_ISDN AF_ISDN
#define PF_PHONET AF_PHONET
#define PF_IEEE802154 AF_IEEE802154
#define PF_MAX AF_MAX
Common:
| Name | Purpose |
|---|---|
| AF_UNIX, AF_LOCAL | Local communication - IPC giữa hai process trên user space với nhau |
| AF_INET, AF_INET6 | IPv4/6 Internet protocols - Giao tiếp giữa process trên user space với TCP/IP stack dưới kernel space |
| AF_NETLINK | Kernel user interface device - Giao tiếp giữa process trên user space với process dưới kernel space |
| ... | ... |
Ex:
AF_NETLINK
AF_INET6
2. Type
#include <bits/sock_type.h>
SOCK_STREAM
Provides sequenced, reliable, two-way, connection-based byte streams. An out-of-band data transmission mechanism may be supported.
SOCK_DGRAM
Supports datagrams (connectionless, unreliable messages of a fixed maximum length).
SOCK_SEQPACKET
Provides a sequenced, reliable, two-way connection-based data transmission path for datagrams of fixed maximum length; a consumer is required to read an entire packet with each input system call.
SOCK_RAW
Provides raw network protocol access.
SOCK_RDM
Provides a reliable datagram layer that does not guarantee ordering.
SOCK_PACKET
Obsolete and should not be used in new programs; see packet(7).
Some socket types may not be implemented by all protocol families.
Since Linux 2.6.27, the type argument serves a second purpose: in addition to specifying a socket type, it may include the bitwise OR of any of the following values, to modify the behavior of socket():
SOCK_NONBLOCK
Set the O_NONBLOCK file status flag on the new open file description. Using this flag saves extra calls to fcntl(2) to achieve the same result.
SOCK_CLOEXEC
Set the close-on-exec (FD_CLOEXEC) flag on the new file descriptor. See the description of the O_CLOEXEC flag in open(2) for reasons why this may be useful.
3. Protocol
Mỗi domain sẽ có những protocol tương ứng với domain đó, ví dụ:
Protocol for AF_INET domain
#include <netinet/in.h>
/* Standard well-defined IP protocols. */
enum
{
IPPROTO_IP = 0, /* Dummy protocol for TCP. */
#define IPPROTO_IP IPPROTO_IP
IPPROTO_HOPOPTS = 0, /* IPv6 Hop-by-Hop options. */
#define IPPROTO_HOPOPTS IPPROTO_HOPOPTS
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. */
#define IPPROTO_IDP IPPROTO_IDP
IPPROTO_TP = 29, /* SO Transport Protocol Class 4. */
#define IPPROTO_TP IPPROTO_TP
IPPROTO_DCCP = 33, /* Datagram Congestion Control Protocol. */
#define IPPROTO_DCCP IPPROTO_DCCP
IPPROTO_IPV6 = 41, /* IPv6 header. */
#define IPPROTO_IPV6 IPPROTO_IPV6
IPPROTO_ROUTING = 43, /* IPv6 routing header. */
#define IPPROTO_ROUTING IPPROTO_ROUTING
IPPROTO_FRAGMENT = 44, /* IPv6 fragmentation header. */
#define IPPROTO_FRAGMENT IPPROTO_FRAGMENT
IPPROTO_RSVP = 46, /* Reservation Protocol. */
#define IPPROTO_RSVP IPPROTO_RSVP
IPPROTO_GRE = 47, /* General Routing Encapsulation. */
#define IPPROTO_GRE IPPROTO_GRE
IPPROTO_ESP = 50, /* encapsulating security payload. */
#define IPPROTO_ESP IPPROTO_ESP
IPPROTO_AH = 51, /* authentication header. */
#define IPPROTO_AH IPPROTO_AH
IPPROTO_ICMPV6 = 58, /* ICMPv6. */
#define IPPROTO_ICMPV6 IPPROTO_ICMPV6
IPPROTO_NONE = 59, /* IPv6 no next header. */
#define IPPROTO_NONE IPPROTO_NONE
IPPROTO_DSTOPTS = 60, /* IPv6 destination options. */
#define IPPROTO_DSTOPTS IPPROTO_DSTOPTS
IPPROTO_MTP = 92, /* Multicast Transport Protocol. */
#define IPPROTO_MTP IPPROTO_MTP
IPPROTO_ENCAP = 98, /* Encapsulation Header. */
#define IPPROTO_ENCAP IPPROTO_ENCAP
IPPROTO_PIM = 103, /* Protocol Independent Multicast. */
#define IPPROTO_PIM IPPROTO_PIM
IPPROTO_COMP = 108, /* Compression Header Protocol. */
#define IPPROTO_COMP IPPROTO_COMP
IPPROTO_SCTP = 132, /* Stream Control Transmission Protocol. */
#define IPPROTO_SCTP IPPROTO_SCTP
IPPROTO_UDPLITE = 136, /* UDP-Lite protocol. */
#define IPPROTO_UDPLITE IPPROTO_UDPLITE
IPPROTO_RAW = 255, /* Raw IP packets. */
#define IPPROTO_RAW IPPROTO_RAW
IPPROTO_MAX
};
Protocol for AF_NETLINK domain
#include <linux/netlink.h>
#define NETLINK_ROUTE 0 /* Routing/device hook */
#define NETLINK_UNUSED 1 /* Unused number */
#define NETLINK_USERSOCK 2 /* Reserved for user mode socket protocols */
#define NETLINK_FIREWALL 3 /* Firewalling hook */
#define NETLINK_INET_DIAG 4 /* INET socket monitoring */
#define NETLINK_NFLOG 5 /* netfilter/iptables ULOG */
#define NETLINK_XFRM 6 /* ipsec */
#define NETLINK_SELINUX 7 /* SELinux event notifications */
#define NETLINK_ISCSI 8 /* Open-iSCSI */
#define NETLINK_AUDIT 9 /* auditing */
#define NETLINK_FIB_LOOKUP 10
#define NETLINK_CONNECTOR 11
#define NETLINK_NETFILTER 12 /* netfilter subsystem */
#define NETLINK_IP6_FW 13
#define NETLINK_DNRTMSG 14 /* DECnet routing messages */
#define NETLINK_KOBJECT_UEVENT 15 /* Kernel messages to userspace */
#define NETLINK_GENERIC 16
/* leave room for NETLINK_DM (DM Events) */
#define NETLINK_SCSITRANSPORT 18 /* SCSI Transports */
#define NETLINK_ECRYPTFS 19
...
