| 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 | } |