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    Contents of /trunk/mkinitrd-magellan/klibc/usr/kinit/ipconfig/dhcp_proto.c

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    Revision 815 - (show annotations) (download)
    Fri Apr 24 18:32:46 2009 UTC (15 years ago) by niro
    File MIME type: text/plain
    File size: 5007 byte(s) 
    -updated to klibc-1.5.15
    1 /*
    2 * DHCP RFC 2131 and 2132
    3 */
    4 #include <sys/types.h>
    5 #include <sys/uio.h>
    6 #include <netinet/in.h>
    7 #include <stdio.h>
    8 #include <string.h>
    9 #include <time.h>
    10
    11 #include "ipconfig.h"
    12 #include "netdev.h"
    13 #include "bootp_packet.h"
    14 #include "bootp_proto.h"
    15 #include "dhcp_proto.h"
    16 #include "packet.h"
    17
    18 static uint8_t dhcp_params[] = {
    19 1, /* subnet mask */
    20 3, /* default gateway */
    21 6, /* DNS server */
    22 12, /* host name */
    23 15, /* domain name */
    24 17, /* root path */
    25 26, /* interface mtu */
    26 28, /* broadcast addr */
    27 40, /* NIS domain name (why?) */
    28 };
    29
    30 static uint8_t dhcp_discover_hdr[] = {
    31 99, 130, 83, 99, /* bootp cookie */
    32 53, 1, DHCPDISCOVER, /* dhcp message type */
    33 55, sizeof(dhcp_params), /* parameter list */
    34 };
    35
    36 static uint8_t dhcp_request_hdr[] = {
    37 99, 130, 83, 99, /* boot cookie */
    38 53, 1, DHCPREQUEST, /* dhcp message type */
    39 #define SERVER_IP_OFF 9
    40 54, 4, 0, 0, 0, 0, /* server IP */
    41 #define REQ_IP_OFF 15
    42 50, 4, 0, 0, 0, 0, /* requested IP address */
    43 55, sizeof(dhcp_params), /* parameter list */
    44 };
    45
    46 static uint8_t dhcp_end[] = {
    47 255,
    48 };
    49
    50 /* Both iovecs below have to have the same structure, since dhcp_send()
    51 pokes at the internals */
    52 #define DHCP_IOV_LEN 6
    53
    54 static struct iovec dhcp_discover_iov[] = {
    55 /* [0] = ip + udp header */
    56 /* [1] = bootp header */
    57 [2] = {dhcp_discover_hdr, sizeof(dhcp_discover_hdr)},
    58 [3] = {dhcp_params, sizeof(dhcp_params)},
    59 /* [4] = DHCP vendor class */
    60 [5] = {dhcp_end, sizeof(dhcp_end)}
    61 };
    62
    63 static struct iovec dhcp_request_iov[] = {
    64 /* [0] = ip + udp header */
    65 /* [1] = bootp header */
    66 [2] = {dhcp_request_hdr, sizeof(dhcp_request_hdr)},
    67 [3] = {dhcp_params, sizeof(dhcp_params)},
    68 /* [4] = DHCP vendor class */
    69 [5] = {dhcp_end, sizeof(dhcp_end)}
    70 };
    71
    72 /*
    73 * Parse a DHCP response packet
    74 * Returns:
    75 * 0 = Not handled
    76 * 2 = DHCPOFFER (from dhcp_proto.h)
    77 * 5 = DHCPACK
    78 * 6 = DHCPNACK
    79 */
    80 static int dhcp_parse(struct netdev *dev, struct bootp_hdr *hdr,
    81 uint8_t * exts, int extlen)
    82 {
    83 uint8_t type = 0;
    84 uint32_t serverid = INADDR_NONE;
    85 int ret = 0;
    86
    87 if (extlen >= 4 && exts[0] == 99 && exts[1] == 130 &&
    88 exts[2] == 83 && exts[3] == 99) {
    89 uint8_t *ext;
    90
    91 for (ext = exts + 4; ext - exts < extlen;) {
    92 uint8_t len, *opt = ext++;
    93 if (*opt == 0)
    94 continue;
    95
    96 len = *ext++;
    97
    98 ext += len;
    99
    100 if (*opt == 53)
    101 type = opt[2];
    102 if (*opt == 54)
    103 memcpy(&serverid, opt + 2, 4);
    104 }
    105 }
    106
    107 switch (type) {
    108 case DHCPOFFER:
    109 ret = bootp_parse(dev, hdr, exts, extlen) ? DHCPOFFER : 0;
    110 if (ret == DHCPOFFER && serverid != INADDR_NONE)
    111 dev->serverid = serverid;
    112 DEBUG(("\n dhcp offer\n"));
    113 break;
    114
    115 case DHCPACK:
    116 ret = bootp_parse(dev, hdr, exts, extlen) ? DHCPACK : 0;
    117 DEBUG(("\n dhcp ack\n"));
    118 break;
    119
    120 case DHCPNAK:
    121 ret = DHCPNAK;
    122 DEBUG(("\n dhcp nak\n"));
    123 break;
    124 }
    125 return ret;
    126 }
    127
    128 /*
    129 * Receive and parse a DHCP packet
    130 * Returns:
    131 *-1 = Error in packet_recv
    132 * 0 = Not handled
    133 * 2 = DHCPOFFER (from dhcp_proto.h)
    134 * 5 = DHCPACK
    135 * 6 = DHCPNACK
    136 */
    137 static int dhcp_recv(struct netdev *dev)
    138 {
    139 struct bootp_hdr bootp;
    140 uint8_t dhcp_options[1500];
    141 struct iovec iov[] = {
    142 /* [0] = ip + udp header */
    143 [1] = {&bootp, sizeof(struct bootp_hdr)},
    144 [2] = {dhcp_options, sizeof(dhcp_options)}
    145 };
    146 int ret;
    147
    148 ret = packet_recv(iov, 3);
    149 if (ret <= 0)
    150 return ret;
    151
    152 DEBUG(("\n dhcp xid %08x ", dev->bootp.xid));
    153
    154 if (ret < sizeof(struct bootp_hdr) || bootp.op != BOOTP_REPLY ||
    155 /* RFC951 7.5 */ bootp.xid != dev->bootp.xid ||
    156 memcmp(bootp.chaddr, dev->hwaddr, 16))
    157 return 0;
    158
    159 ret -= sizeof(struct bootp_hdr);
    160
    161 return dhcp_parse(dev, &bootp, dhcp_options, ret);
    162 }
    163
    164 static int dhcp_send(struct netdev *dev, struct iovec *vec)
    165 {
    166 struct bootp_hdr bootp;
    167
    168 memset(&bootp, 0, sizeof(struct bootp_hdr));
    169
    170 bootp.op = BOOTP_REQUEST;
    171 bootp.htype = dev->hwtype;
    172 bootp.hlen = dev->hwlen;
    173 bootp.xid = dev->bootp.xid;
    174 bootp.ciaddr = dev->ip_addr;
    175 bootp.giaddr = INADDR_ANY;
    176 bootp.secs = htons(time(NULL) - dev->open_time);
    177 memcpy(bootp.chaddr, dev->hwaddr, 16);
    178
    179 vec[1].iov_base = &bootp;
    180 vec[1].iov_len = sizeof(struct bootp_hdr);
    181
    182 vec[4].iov_base = vendor_class_identifier;
    183 vec[4].iov_len = vendor_class_identifier_len;
    184
    185 DEBUG(("xid %08x secs %d ", bootp.xid, ntohs(bootp.secs)));
    186
    187 return packet_send(dev, vec, DHCP_IOV_LEN);
    188 }
    189
    190 /*
    191 * Send a DHCP discover packet
    192 */
    193 int dhcp_send_discover(struct netdev *dev)
    194 {
    195 dev->ip_addr = INADDR_ANY;
    196 dev->ip_gateway = INADDR_ANY;
    197
    198 DEBUG(("-> dhcp discover "));
    199
    200 return dhcp_send(dev, dhcp_discover_iov);
    201 }
    202
    203 /*
    204 * Receive a DHCP offer packet
    205 */
    206 int dhcp_recv_offer(struct netdev *dev)
    207 {
    208 return dhcp_recv(dev);
    209 }
    210
    211 /*
    212 * Send a DHCP request packet
    213 */
    214 int dhcp_send_request(struct netdev *dev)
    215 {
    216 memcpy(&dhcp_request_hdr[SERVER_IP_OFF], &dev->serverid, 4);
    217 memcpy(&dhcp_request_hdr[REQ_IP_OFF], &dev->ip_addr, 4);
    218
    219 DEBUG(("-> dhcp request "));
    220
    221 return dhcp_send(dev, dhcp_request_iov);
    222 }
    223
    224 /*
    225 * Receive a DHCP ack packet
    226 */
    227 int dhcp_recv_ack(struct netdev *dev)
    228 {
    229 return dhcp_recv(dev);
    230 }