Sockets: Socket options Related system calls

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System calls related to socket options:

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Set the value in the cell pointed to by optval to the optname option:

int setsockopt(int sockfd, int level, int optname, const void *optval,socklen_t optlen);

Get the current value of the optname option and put it in the cell that optval points to:

int getsockopt(int sockfd, int level, int optname, void *optval,socklen_t *optlen);

Note that the last parameter is a pointer.

SOCKFD: Point to an already opened socket descriptor

Optlen: Specifies the size of the Optval

Optval: Store the value to get or set, type reference table

The other three parameters level, optname reference the corresponding table.

Socket options related to the SCTP library function:

int sctp_opt_info(int sockfd,

sctp_assoc_t assoc_id,//identification of possible associations

int opt,//socket option

void *arg,//socket option parameter

socklen_t *siz//parameter size

);

Gets the function of the SCTP socket option (similar to getsockopt)

Socket Options Categories:

Flag option: Enables or disables the two-tuple option for an attribute, at which time *optval is int or u_int, *optval=0 is disabled, and other means enabled.

Value options: A specific value for the option.

For socket options, for the state of the socket, when to set or get to consider timing issues.

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Sockets (Data Link layer): The so-called universal socket option, which is independent of the Protocol.

Level:sol_socket

Optname:

So_broadcast: The ability to enable or disable a process to send broadcast messages (only UDP support).

So_debug: (only TCP support).

So_dontroute: Specifies that outgoing packets will bypass the normal routing mechanism of the underlying protocol.

So_error: Error returned

So_keepalive: Stay Alive

So_linger: Specifies the close function for the connection-oriented protocol (TCP\SCTP) if the operation.

So_oobinline: When this option is turned on, out-of-band data is left in the normal input queue.

SO_RCVBUF: Modifying the size of the socket receive buffer

SO_SNDBUF: Modifying the size of the socket send buffer

So_rcvlowat:

So_sndlowat:

So_rcvtimeo: Setting the Receive timeout time

So_sndtimeo: Set Send timeout time

SO_REUSEADDR: Prevents the address from being reused, that is, only one connection is allowed.

So_reuseport: Prevents the port from being reused, that is, it can only have one connection.

So_type:

So_useloopback:

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IPV4 (Network layer):

Level:ipproto_ip

Optname:

IP_HDRINCL:

Ip_options:

IP_RECVDSTADDR:

Ip_recvif:

Ip_tos:

Ip_ttl:

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IPV6 (Network layer)):

Level:ipproto_ipv6

Optname:

Ipv6_checksum:

Ipv6_dontfrag:

Ipv6_nexthop:

IPV6_PATHMTU:

Ipv6_recvdstopts:

Ipv6_recvhoplimit:

Ipv6_recvhopopts:

Ipv6_recvpathmty:

Ipv6_recvpktinfo:

IPV6_RECVRTHRD:

Ipv6_recvtclass:

Ipv6_unicast_hops:

IPV6_USE_MIN_MTU:

Ipv6_v6only:

IPV6_XXX:

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ICMPV6 (Network layer):

Level:ipproto_icmpv6

Optname:

Icmp6_filter:

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TCP (Transport Layer):

Level:ipproto_tcp

Optname:

TCP_MAXSEG:

Tcp_nodelay:

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SCTP (Transport Layer):

Level:ipproto_sctp

Optname:

Sctp_adaption_layer:

Sctp_associnfo:

Sctp_autoclose:

Sctp_default_send_param:

Sctp_disable_fragments:

Sctp_events: Book Eight events

Sctp_get_peer_addr_info:

SCTP_I_WANT_MAPPED_V4_ADDR:

SCTP_INITMSG: Initializing some information

Sctp_maxburst:

SCTP_MAXSEG:

Sctp_nodelay:

Sctp_peer_addr_params:

SCTP_PRIMARY_ADDR:

Sctp_rtoinfo:

SCTP_SET_PEER_PRIMARY_ADDR:

Sctp_status:

Some of the structure of sockets:

struct SCTP_INITMSG

{

__u16 Sinit_num_ostreams;

__u16 Sinit_max_instreams;

__u16 sinit_max_attempts;

__u16 Sinit_max_init_timeo;

};

Sockets: Socket options Related system calls