1 /* in_pcb.c 4.16 82/02/15 */ 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 * TODO: 45 * use hashing 46 */ 47 struct in_addr zeroin_addr; 48 49 /* 50 * Allocate a protocol control block, space 51 * for send and receive data, and local host information. 52 * Return error. If no error make socket point at pcb. 53 */ 54 in_pcbattach(so, head, sndcc, rcvcc, sin) 55 struct socket *so; 56 struct inpcb *head; 57 int sndcc, rcvcc; 58 struct sockaddr_in *sin; 59 { 60 struct mbuf *m; 61 register struct inpcb *inp; 62 struct ifnet *ifp; 63 u_short lport; 64 65 COUNT(IN_PCBATTACH); 66 if (sin) { 67 if (sin->sin_family != AF_INET) 68 return (EAFNOSUPPORT); 69 if (ifnet && sin->sin_addr.s_addr == 0) 70 sin->sin_addr = ifnet->if_addr; 71 ifp = if_ifwithaddr(sin->sin_addr); 72 lport = sin->sin_port; 73 if (lport && 74 in_pcblookup(head, zeroin_addr, 0, sin->sin_addr, lport)) 75 return (EADDRINUSE); 76 } else { 77 ifp = ifnet; 78 lport = 0; 79 } 80 if (ifp == 0) 81 return (EADDRNOTAVAIL); 82 m = m_getclr(M_DONTWAIT); 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_head = head; 91 inp->inp_laddr = ifp->if_addr; 92 if (lport == 0) 93 do { 94 if (head->inp_lport++ < 1024) 95 head->inp_lport = 1024; 96 lport = htons(head->inp_lport); 97 } while (in_pcblookup(head, zeroin_addr, 0, inp->inp_laddr, lport)); 98 inp->inp_lport = lport; 99 inp->inp_socket = so; 100 insque(inp, head); 101 so->so_pcb = (caddr_t)inp; 102 sin = (struct sockaddr_in *)&so->so_addr; 103 sin->sin_family = AF_INET; 104 sin->sin_addr = inp->inp_laddr; 105 sin->sin_port = inp->inp_lport; 106 return (0); 107 bad2: 108 sbrelease(&so->so_snd); 109 bad: 110 (void) m_free(m); 111 return (ENOBUFS); 112 } 113 114 in_pcbconnect(inp, sin) 115 struct inpcb *inp; 116 struct sockaddr_in *sin; 117 { 118 struct inpcb *xp; 119 120 COUNT(IN_PCBCONNECT); 121 if (sin->sin_family != AF_INET) 122 return (EAFNOSUPPORT); 123 if (sin->sin_addr.s_addr == 0 || sin->sin_port == 0) 124 return (EADDRNOTAVAIL); 125 xp = in_pcblookup(inp->inp_head, sin->sin_addr, sin->sin_port, inp->inp_laddr, inp->inp_lport); 126 if (xp->inp_faddr.s_addr) 127 return (EADDRINUSE); 128 inp->inp_faddr = sin->sin_addr; 129 inp->inp_fport = sin->sin_port; 130 return (0); 131 } 132 133 in_pcbconnaddr(inp, sp) 134 struct inpcb *inp; 135 struct sockaddr *sp; 136 { 137 register struct sockaddr_in *sin = (struct sockaddr_in *)sp; 138 139 sin->sin_family = AF_INET; 140 sin->sin_port = inp->inp_fport; 141 sin->sin_addr = inp->inp_faddr; 142 } 143 144 in_pcbdisconnect(inp) 145 struct inpcb *inp; 146 { 147 148 COUNT(IN_PCBDISCONNECT); 149 inp->inp_faddr.s_addr = 0; 150 if (inp->inp_socket->so_state & SS_USERGONE) 151 in_pcbdetach(inp); 152 } 153 154 in_pcbdetach(inp) 155 struct inpcb *inp; 156 { 157 struct socket *so = inp->inp_socket; 158 159 so->so_pcb = 0; 160 sofree(so); 161 remque(inp); 162 (void) m_free(dtom(inp)); 163 } 164 165 /* 166 * Look for a control block to accept a segment. 167 * First choice is an exact address match. 168 * Second choice is a match of local address, with 169 * unspecified foreign address. 170 */ 171 struct inpcb * 172 in_pcblookup(head, faddr, fport, laddr, lport) 173 struct inpcb *head; 174 struct in_addr faddr, laddr; 175 u_short fport, lport; 176 { 177 register struct inpcb *inp; 178 struct inpcb *match = 0; 179 180 for (inp = head->inp_next; inp != head; inp = inp->inp_next) { 181 if (inp->inp_laddr.s_addr != laddr.s_addr || 182 inp->inp_lport != lport) 183 continue; 184 if (inp->inp_faddr.s_addr == 0) { 185 match = inp; 186 continue; 187 } 188 if (inp->inp_faddr.s_addr == faddr.s_addr && 189 inp->inp_fport == fport) 190 return (inp); 191 } 192 return (match); 193 } 194