Socket structs

addrinfo

struct addrinfo 
{
  int ai_flags;          // AI_PASSIVE, AI_CANONNAME, etc.
  int ai_family;         // AF_INET, AF_INET6, AF_UNSPEC
  int ai_socktype;       // SOCK_STREAM, SOCK_DGRAM
  int ai_protocol;       // use 0 for "any"
  size_t ai_addrlen;     // size of ai_addr in bytes
  struct sockaddr *ai_addr; // struct sockaddr_in or _in6
  char *ai_canonname;    // full canonical hostname
  struct addrinfo *ai_next; // linked list, next node
};