cmsghdr

Contains information about ancillary data.

Service:Networking

Syntax

  #include <sys/socket.h>
  
  struct cmsghdr
  {
     socklen_t      cmsg_len;
     int            cmsg_level; 
     int            cmsg_type; 
  };

Fields

cmsg_len: Specifies the length of the ancillary data, including the header.
cmsg_level: Specifies the protocol that created the data.
cmsg_type: Specifies the protocol-specific type of data. For possible types, see Socket Types.

Remarks

An ancillary data object consists of a cmsghdr structure, which is the header, followed by cmsg_data [1], which contains the actually data.