1 /* in_pcb.c 4.11 81/12/02 */ 2 3 #include "../h/param.h" 4 #include "../h/systm.h" 5 #include "../h/dir.h" 6 #include "../h/user.h" 7 #include "../h/mbuf.h" 8 #include "../h/socket.h" 9 #include "../h/socketvar.h" 10 #include "../net/in.h" 11 #include "../net/in_systm.h" 12 #include "../net/if.h" 13 #include "../net/in_pcb.h" 14 15 /* 16 * Routines to manage internet protocol control blocks. 17 * 18 * At PRU_ATTACH time a protocol control block is allocated in 19 * in_pcballoc() and inserted on a doubly-linked list of such blocks 20 * for the protocol. A port address is either requested (and verified 21 * to not be in use) or assigned at this time. We also allocate 22 * space in the socket sockbuf structures here, although this is 23 * not a clearly correct place to put this function. 24 * 25 * A connectionless protocol will have its protocol control block 26 * removed at PRU_DETACH time, when the socket will be freed (freeing 27 * the space reserved) and the block will be removed from the list of 28 * blocks for its protocol. 29 * 30 * A connection-based protocol may be connected to a remote peer at 31 * PRU_CONNECT time through the routine in_pcbconnect(). In the normal 32 * case a PRU_DISCONNECT occurs causing a in_pcbdisconnect(). 33 * It is also possible that higher-level routines will opt out of the 34 * relationship with the connection before the connection shut down 35 * is complete. This often occurs in protocols like TCP where we must 36 * hold on to the protocol control block for a unreasonably long time 37 * after the connection is used up to avoid races in later connection 38 * establishment. To handle this we allow higher-level routines to 39 * disassociate themselves from the socket, marking it SS_USERGONE while 40 * the disconnect is in progress. We notice that this has happened 41 * when the disconnect is complete, and perform the PRU_DETACH operation, 42 * freeing the socket. 43 */ 44 45 /* 46 * Allocate a protocol control block, space 47 * for send and receive data, and local host information. 48 * Return error. If no error make socket point at pcb. 49 */ 50 in_pcbattach(so, head, sndcc, rcvcc, sin) 51 struct socket *so; 52 struct inpcb *head; 53 int sndcc, rcvcc; 54 struct sockaddr_in *sin; 55 { 56 struct mbuf *m; 57 register struct inpcb *inp, *xp; 58 struct ifnet *ifp; 59 u_long lport; 60 61 COUNT(IN_PCBATTACH); 62 if (sin) { 63 if (sin->sin_family != AF_INET) 64 return (EAFNOSUPPORT); 65 ifp = if_ifwithaddr(sin->sin_addr); 66 if (ifp == 0) 67 return (EADDRNOTAVAIL); 68 lport = sin->sin_port; 69 if (lport) { 70 xp = head->inp_next; 71 for (; xp != head; xp = xp->inp_next) 72 if (xp->inp_laddr.s_addr == 73 sin->sin_addr.s_addr && 74 xp->inp_lport == lport && 75 xp->inp_faddr.s_addr == 0) 76 return (EADDRINUSE); 77 } 78 } else { 79 ifp = if_ifwithaddr(ifnet->if_addr); 80 lport = 0; 81 } 82 m = m_getclr(M_WAIT); 83 if (m == 0) 84 return (ENOBUFS); 85 if (sbreserve(&so->so_snd, sndcc) == 0) 86 goto bad; 87 if (sbreserve(&so->so_rcv, rcvcc) == 0) 88 goto bad2; 89 inp = mtod(m, struct inpcb *); 90 inp->inp_laddr = ifp->if_addr; 91 if (lport) 92 goto gotport; 93 again: 94 if (head->inp_lport++ < 1024) 95 head->inp_lport = 1024; 96 for (xp = head->inp_next; xp != head; xp = xp->inp_next) 97 if (xp->inp_lport == head->inp_lport) 98 goto again; 99 lport = htons(head->inp_lport); 100 gotport: 101 inp->inp_socket = so; 102 inp->inp_lport = lport; 103 insque(inp, head); 104 so->so_pcb = (caddr_t)inp; 105 sin = (struct sockaddr_in *)&so->so_addr; 106 sin->sin_family = AF_INET; 107 sin->sin_addr = inp->inp_laddr; 108 sin->sin_port = inp->inp_lport; 109 return (0); 110 bad2: 111 sbrelease(&so->so_snd); 112 bad: 113 (void) m_free(m); 114 return (ENOBUFS); 115 } 116 117 in_pcbconnect(inp, sin) 118 struct inpcb *inp; 119 struct sockaddr_in *sin; 120 { 121 122 COUNT(IN_PCBCONNECT); 123 if (sin->sin_family != AF_INET) 124 return (EAFNOSUPPORT); 125 if (sin->sin_addr.s_addr == 0 || sin->sin_port == 0) 126 return (EADDRNOTAVAIL); 127 /* should check not already in use... */ 128 inp->inp_faddr = sin->sin_addr; 129 inp->inp_fport = sin->sin_port; 130 return (0); 131 } 132 133 in_pcbdisconnect(inp) 134 struct inpcb *inp; 135 { 136 137 COUNT(IN_PCBDISCONNECT); 138 inp->inp_faddr.s_addr = 0; 139 if (inp->inp_socket->so_state & SS_USERGONE) 140 in_pcbdetach(inp); 141 } 142 143 in_pcbdetach(inp) 144 struct inpcb *inp; 145 { 146 struct socket *so = inp->inp_socket; 147 148 so->so_pcb = 0; 149 sofree(so); 150 remque(inp); 151 (void) m_free(dtom(inp)); 152 } 153 154 /* 155 * Look for a control block to accept a segment. 156 * First choice is an exact address match. 157 * Second choice is a match of local address, with 158 * unspecified foreign address. 159 */ 160 struct inpcb * 161 in_pcblookup(head, faddr, fport, laddr, lport) 162 struct inpcb *head; 163 struct in_addr faddr, laddr; 164 u_short fport, lport; 165 { 166 register struct inpcb *inp; 167 struct inpcb *match = 0; 168 169 for (inp = head->inp_next; inp != head; inp = inp->inp_next) { 170 if (inp->inp_laddr.s_addr != laddr.s_addr || 171 inp->inp_lport != lport) 172 continue; 173 if (inp->inp_faddr.s_addr == 0) { 174 match = inp; 175 continue; 176 } 177 if (inp->inp_faddr.s_addr == faddr.s_addr && 178 inp->inp_fport == fport) 179 return (inp); 180 } 181 return (match); 182 } 183