1 /* udp_usrreq.c 4.20 82/02/27 */ 2 3 #include "../h/param.h" 4 #include "../h/dir.h" 5 #include "../h/user.h" 6 #include "../h/mbuf.h" 7 #include "../h/protosw.h" 8 #include "../h/socket.h" 9 #include "../h/socketvar.h" 10 #include "../net/in.h" 11 #include "../net/in_pcb.h" 12 #include "../net/in_systm.h" 13 #include "../net/ip.h" 14 #include "../net/ip_var.h" 15 #include "../net/udp.h" 16 #include "../net/udp_var.h" 17 18 /* 19 * UDP protocol implementation. 20 * Per RFC 768, August, 1980. 21 */ 22 udp_init() 23 { 24 25 COUNT(UDP_INIT); 26 udb.inp_next = udb.inp_prev = &udb; 27 } 28 29 int udpcksum; 30 struct sockaddr_in udp_in = { AF_INET }; 31 32 udp_input(m0) 33 struct mbuf *m0; 34 { 35 register struct udpiphdr *ui; 36 register struct inpcb *inp; 37 register struct mbuf *m; 38 int len, ulen; 39 40 COUNT(UDP_INPUT); 41 /* 42 * Get IP and UDP header together in first mbuf. 43 */ 44 m = m0; 45 if ((m->m_off > MMAXOFF || m->m_len < sizeof (struct udpiphdr)) && 46 (m = m_pullup(m, sizeof (struct udpiphdr))) == 0) { 47 udpstat.udps_hdrops++; 48 return; 49 } 50 ui = mtod(m, struct udpiphdr *); 51 if (((struct ip *)ui)->ip_hl > (sizeof (struct ip) >> 2)) 52 ip_stripoptions((struct ip *)ui, (struct mbuf *)0); 53 54 /* 55 * Make mbuf data length reflect UDP length. 56 * If not enough data to reflect UDP length, drop. 57 */ 58 ulen = ntohs((u_short)ui->ui_ulen); 59 len = sizeof (struct udphdr) + ulen; 60 if (((struct ip *)ui)->ip_len != len) { 61 if (len > ((struct ip *)ui)->ip_len) { 62 udpstat.udps_badlen++; 63 goto bad; 64 } 65 m_adj(m, ((struct ip *)ui)->ip_len - len); 66 /* (struct ip *)ui->ip_len = len; */ 67 } 68 69 /* 70 * Checksum extended UDP header and data. 71 */ 72 if (udpcksum) { 73 ui->ui_next = ui->ui_prev = 0; 74 ui->ui_x1 = 0; 75 ui->ui_len = htons((u_short)(sizeof (struct udphdr) + ulen)); 76 if (ui->ui_sum = in_cksum(m, len)) { 77 udpstat.udps_badsum++; 78 printf("udp cksum %x\n", ui->ui_sum); 79 m_freem(m); 80 return; 81 } 82 } 83 84 /* 85 * Locate pcb for datagram. On wildcard match, update 86 * control block to anchor network and host address. 87 */ 88 inp = in_pcblookup(&udb, 89 ui->ui_src, ui->ui_sport, ui->ui_dst, ui->ui_dport, 1); 90 if (inp == 0) 91 goto bad; 92 93 /* 94 * Construct sockaddr format source address. 95 * Stuff source address and datagram in user buffer. 96 */ 97 udp_in.sin_port = ui->ui_sport; 98 udp_in.sin_addr = ui->ui_src; 99 m->m_len -= sizeof (struct udpiphdr); 100 m->m_off += sizeof (struct udpiphdr); 101 if (sbappendaddr(&inp->inp_socket->so_rcv, (struct sockaddr *)&udp_in, m) == 0) 102 goto bad; 103 sorwakeup(inp->inp_socket); 104 return; 105 bad: 106 m_freem(m); 107 } 108 109 udp_ctlinput(m) 110 struct mbuf *m; 111 { 112 113 COUNT(UDP_CTLINPUT); 114 m_freem(m); 115 } 116 117 udp_output(inp, m0) 118 struct inpcb *inp; 119 struct mbuf *m0; 120 { 121 register struct mbuf *m; 122 register struct udpiphdr *ui; 123 register int len = 0; 124 125 COUNT(UDP_OUTPUT); 126 /* 127 * Calculate data length and get a mbuf 128 * for UDP and IP headers. 129 */ 130 for (m = m0; m; m = m->m_next) 131 len += m->m_len; 132 m = m_get(M_DONTWAIT); 133 if (m == 0) 134 goto bad; 135 136 /* 137 * Fill in mbuf with extended UDP header 138 * and addresses and length put into network format. 139 */ 140 m->m_off = MMAXOFF - sizeof (struct udpiphdr); 141 m->m_len = sizeof (struct udpiphdr); 142 m->m_next = m0; 143 ui = mtod(m, struct udpiphdr *); 144 ui->ui_next = ui->ui_prev = 0; 145 ui->ui_x1 = 0; 146 ui->ui_pr = IPPROTO_UDP; 147 ui->ui_len = sizeof (struct udpiphdr) + len; 148 ui->ui_src = inp->inp_laddr; 149 ui->ui_dst = inp->inp_faddr; 150 ui->ui_sport = inp->inp_lport; 151 ui->ui_dport = inp->inp_fport; 152 ui->ui_ulen = htons((u_short)len); 153 154 /* 155 * Stuff checksum and output datagram. 156 */ 157 ui->ui_sum = 0; 158 ui->ui_sum = in_cksum(m, sizeof (struct udpiphdr) + len); 159 ((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len; 160 ((struct ip *)ui)->ip_ttl = MAXTTL; 161 (void) ip_output(m, (struct mbuf *)0); 162 return; 163 bad: 164 m_freem(m); 165 } 166 167 udp_usrreq(so, req, m, addr) 168 struct socket *so; 169 int req; 170 struct mbuf *m; 171 caddr_t addr; 172 { 173 struct inpcb *inp = sotoinpcb(so); 174 int error; 175 176 COUNT(UDP_USRREQ); 177 if (inp == 0 && req != PRU_ATTACH) 178 return (EINVAL); 179 switch (req) { 180 181 case PRU_ATTACH: 182 if (inp != 0) 183 return (EINVAL); 184 error = in_pcbattach(so, &udb, 2048, 2048, (struct sockaddr_in *)addr); 185 if (error) 186 return (error); 187 break; 188 189 case PRU_DETACH: 190 if (inp == 0) 191 return (ENOTCONN); 192 in_pcbdetach(inp); 193 break; 194 195 case PRU_CONNECT: 196 if (inp->inp_faddr.s_addr) 197 return (EISCONN); 198 error = in_pcbconnect(inp, (struct sockaddr_in *)addr); 199 if (error) 200 return (error); 201 soisconnected(so); 202 break; 203 204 case PRU_ACCEPT: 205 return (EOPNOTSUPP); 206 207 case PRU_DISCONNECT: 208 if (inp->inp_faddr.s_addr == 0) 209 return (ENOTCONN); 210 in_pcbdisconnect(inp); 211 soisdisconnected(so); 212 break; 213 214 case PRU_SHUTDOWN: 215 socantsendmore(so); 216 break; 217 218 case PRU_SEND: { 219 struct in_addr laddr; 220 221 if (addr) { 222 laddr = inp->inp_laddr; 223 if (inp->inp_faddr.s_addr) 224 return (EISCONN); 225 error = in_pcbconnect(inp, (struct sockaddr_in *)addr); 226 if (error) 227 return (error); 228 } else { 229 if (inp->inp_faddr.s_addr == 0) 230 return (ENOTCONN); 231 } 232 udp_output(inp, m); 233 if (addr) { 234 in_pcbdisconnect(inp); 235 inp->inp_laddr = laddr; 236 } 237 } 238 break; 239 240 case PRU_ABORT: 241 in_pcbdetach(inp); 242 sofree(so); 243 soisdisconnected(so); 244 break; 245 246 case PRU_CONTROL: 247 return (EOPNOTSUPP); 248 249 default: 250 panic("udp_usrreq"); 251 } 252 return (0); 253 } 254