-/* in_pcb.c 4.9 81/11/26 */
+/* in_pcb.c 4.16 82/02/15 */
#include "../h/param.h"
#include "../h/systm.h"
#include "../net/if.h"
#include "../net/in_pcb.h"
+/*
+ * Routines to manage internet protocol control blocks.
+ *
+ * At PRU_ATTACH time a protocol control block is allocated in
+ * in_pcballoc() and inserted on a doubly-linked list of such blocks
+ * for the protocol. A port address is either requested (and verified
+ * to not be in use) or assigned at this time. We also allocate
+ * space in the socket sockbuf structures here, although this is
+ * not a clearly correct place to put this function.
+ *
+ * A connectionless protocol will have its protocol control block
+ * removed at PRU_DETACH time, when the socket will be freed (freeing
+ * the space reserved) and the block will be removed from the list of
+ * blocks for its protocol.
+ *
+ * A connection-based protocol may be connected to a remote peer at
+ * PRU_CONNECT time through the routine in_pcbconnect(). In the normal
+ * case a PRU_DISCONNECT occurs causing a in_pcbdisconnect().
+ * It is also possible that higher-level routines will opt out of the
+ * relationship with the connection before the connection shut down
+ * is complete. This often occurs in protocols like TCP where we must
+ * hold on to the protocol control block for a unreasonably long time
+ * after the connection is used up to avoid races in later connection
+ * establishment. To handle this we allow higher-level routines to
+ * disassociate themselves from the socket, marking it SS_USERGONE while
+ * the disconnect is in progress. We notice that this has happened
+ * when the disconnect is complete, and perform the PRU_DETACH operation,
+ * freeing the socket.
+ *
+ * TODO:
+ * use hashing
+ */
+struct in_addr zeroin_addr;
+
/*
* Allocate a protocol control block, space
* for send and receive data, and local host information.
* Return error. If no error make socket point at pcb.
*/
-in_pcballoc(so, head, sndcc, rcvcc, sin)
+in_pcbattach(so, head, sndcc, rcvcc, sin)
struct socket *so;
struct inpcb *head;
int sndcc, rcvcc;
struct sockaddr_in *sin;
{
struct mbuf *m;
- register struct inpcb *inp, *xp;
+ register struct inpcb *inp;
struct ifnet *ifp;
- u_long lport;
+ u_short lport;
+COUNT(IN_PCBATTACH);
if (sin) {
if (sin->sin_family != AF_INET)
return (EAFNOSUPPORT);
+ if (ifnet && sin->sin_addr.s_addr == 0)
+ sin->sin_addr = ifnet->if_addr;
ifp = if_ifwithaddr(sin->sin_addr);
- if (ifp == 0)
- return (EADDRNOTAVAIL);
lport = sin->sin_port;
- if (lport) {
- xp = head->inp_next;
- for (; xp != head; xp = inp->inp_next)
- if (xp->inp_laddr.s_addr ==
- sin->sin_addr.s_addr &&
- xp->inp_lport == lport &&
- xp->inp_faddr.s_addr == 0)
- return (EADDRINUSE);
- }
+ if (lport &&
+ in_pcblookup(head, zeroin_addr, 0, sin->sin_addr, lport))
+ return (EADDRINUSE);
} else {
- ifp = if_ifwithaddr(ifnet->if_addr);
+ ifp = ifnet;
lport = 0;
}
- m = m_getclr(M_WAIT);
+ if (ifp == 0)
+ return (EADDRNOTAVAIL);
+ m = m_getclr(M_DONTWAIT);
if (m == 0)
return (ENOBUFS);
if (sbreserve(&so->so_snd, sndcc) == 0)
if (sbreserve(&so->so_rcv, rcvcc) == 0)
goto bad2;
inp = mtod(m, struct inpcb *);
+ inp->inp_head = head;
inp->inp_laddr = ifp->if_addr;
- if (lport)
- goto gotport;
-again:
- if (head->inp_lport++ < 1024)
- head->inp_lport = 1024;
- for (xp = head->inp_next; xp != head; xp = xp->inp_next)
- if (xp->inp_lport == head->inp_lport)
- goto again;
- lport = head->inp_lport;
-gotport:
- inp->inp_socket = so;
+ if (lport == 0)
+ do {
+ if (head->inp_lport++ < 1024)
+ head->inp_lport = 1024;
+ lport = htons(head->inp_lport);
+ } while (in_pcblookup(head, zeroin_addr, 0, inp->inp_laddr, lport));
inp->inp_lport = lport;
+ inp->inp_socket = so;
insque(inp, head);
so->so_pcb = (caddr_t)inp;
sin = (struct sockaddr_in *)&so->so_addr;
return (ENOBUFS);
}
-in_pcbsetpeer(inp, sin)
+in_pcbconnect(inp, sin)
struct inpcb *inp;
struct sockaddr_in *sin;
{
+ struct inpcb *xp;
+COUNT(IN_PCBCONNECT);
if (sin->sin_family != AF_INET)
return (EAFNOSUPPORT);
if (sin->sin_addr.s_addr == 0 || sin->sin_port == 0)
return (EADDRNOTAVAIL);
- /* should check not already in use... */
+ xp = in_pcblookup(inp->inp_head, sin->sin_addr, sin->sin_port, inp->inp_laddr, inp->inp_lport);
+ if (xp->inp_faddr.s_addr)
+ return (EADDRINUSE);
inp->inp_faddr = sin->sin_addr;
inp->inp_fport = sin->sin_port;
return (0);
}
-in_pcbfree(inp)
+in_pcbconnaddr(inp, sp)
+ struct inpcb *inp;
+ struct sockaddr *sp;
+{
+ register struct sockaddr_in *sin = (struct sockaddr_in *)sp;
+
+ sin->sin_family = AF_INET;
+ sin->sin_port = inp->inp_fport;
+ sin->sin_addr = inp->inp_faddr;
+}
+
+in_pcbdisconnect(inp)
+ struct inpcb *inp;
+{
+
+COUNT(IN_PCBDISCONNECT);
+ inp->inp_faddr.s_addr = 0;
+ if (inp->inp_socket->so_state & SS_USERGONE)
+ in_pcbdetach(inp);
+}
+
+in_pcbdetach(inp)
struct inpcb *inp;
{
struct socket *so = inp->inp_socket;
(void) m_free(dtom(inp));
}
+/*
+ * Look for a control block to accept a segment.
+ * First choice is an exact address match.
+ * Second choice is a match of local address, with
+ * unspecified foreign address.
+ */
struct inpcb *
in_pcblookup(head, faddr, fport, laddr, lport)
struct inpcb *head;
u_short fport, lport;
{
register struct inpcb *inp;
+ struct inpcb *match = 0;
- for (inp = head->inp_next; inp != head; inp = inp->inp_next)
+ for (inp = head->inp_next; inp != head; inp = inp->inp_next) {
+ if (inp->inp_laddr.s_addr != laddr.s_addr ||
+ inp->inp_lport != lport)
+ continue;
+ if (inp->inp_faddr.s_addr == 0) {
+ match = inp;
+ continue;
+ }
if (inp->inp_faddr.s_addr == faddr.s_addr &&
- inp->inp_fport == fport &&
- inp->inp_laddr.s_addr == laddr.s_addr &&
- inp->inp_lport == lport)
+ inp->inp_fport == fport)
return (inp);
- for (inp = head->inp_next; inp != head; inp = inp->inp_next)
- if ((inp->inp_faddr.s_addr == faddr.s_addr ||
- inp->inp_faddr.s_addr == 0) &&
- (inp->inp_fport == fport || inp->inp_fport == 0) &&
- inp->inp_laddr.s_addr == laddr.s_addr &&
- (inp->inp_lport == lport || inp->inp_lport == 0))
- return (inp);
- return (0);
+ }
+ return (match);
}