diff options
Diffstat (limited to 'slirp/bootp.c')
| -rw-r--r-- | slirp/bootp.c | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/slirp/bootp.c b/slirp/bootp.c new file mode 100644 index 0000000..7e4b5ba --- /dev/null +++ b/slirp/bootp.c @@ -0,0 +1,212 @@ +/* + * QEMU BOOTP/DHCP server + * + * Copyright (c) 2004 Fabrice Bellard + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +#include <slirp.h> + +/* XXX: only DHCP is supported */ + +#define NB_ADDR 16 + +#define START_ADDR 15 + +#define LEASE_TIME (24 * 3600) + +typedef struct { + uint8_t allocated; +} BOOTPClient; + +BOOTPClient bootp_clients[NB_ADDR]; + +static const uint8_t rfc1533_cookie[] = { RFC1533_COOKIE }; + +#ifdef DEBUG +#define dprintf(fmt, args...) \ +if (slirp_debug & DBG_CALL) { fprintf(dfd, fmt, ## args); fflush(dfd); } +#else +#define dprintf(fmt, args...) +#endif + +static BOOTPClient *get_new_addr(struct in_addr *paddr) +{ + BOOTPClient *bc; + int i; + + for(i = 0; i < NB_ADDR; i++) { + if (!bootp_clients[i].allocated) + goto found; + } + return NULL; + found: + bc = &bootp_clients[i]; + bc->allocated = 1; + paddr->s_addr = htonl(ntohl(special_addr.s_addr) | (i + START_ADDR)); + return bc; +} + +static void dhcp_decode(const uint8_t *buf, int size, + int *pmsg_type) +{ + const uint8_t *p, *p_end; + int len, tag; + + *pmsg_type = 0; + + p = buf; + p_end = buf + size; + if (size < 5) + return; + if (memcmp(p, rfc1533_cookie, 4) != 0) + return; + p += 4; + while (p < p_end) { + tag = p[0]; + if (tag == RFC1533_PAD) { + p++; + } else if (tag == RFC1533_END) { + break; + } else { + p++; + if (p >= p_end) + break; + len = *p++; + dprintf("dhcp: tag=0x%02x len=%d\n", tag, len); + + switch(tag) { + case RFC2132_MSG_TYPE: + if (len >= 1) + *pmsg_type = p[0]; + break; + default: + break; + } + p += len; + } + } +} + +static void bootp_reply(struct bootp_t *bp) +{ + BOOTPClient *bc; + struct mbuf *m; + struct bootp_t *rbp; + struct sockaddr_in saddr, daddr; + struct in_addr dns_addr; + int dhcp_msg_type, val; + uint8_t *q; + + /* extract exact DHCP msg type */ + dhcp_decode(bp->bp_vend, DHCP_OPT_LEN, &dhcp_msg_type); + dprintf("bootp packet op=%d msgtype=%d\n", bp->bp_op, dhcp_msg_type); + + if (dhcp_msg_type != DHCPDISCOVER && + dhcp_msg_type != DHCPREQUEST) + return; + /* XXX: this is a hack to get the client mac address */ + memcpy(client_ethaddr, bp->bp_hwaddr, 6); + + if ((m = m_get()) == NULL) + return; + m->m_data += if_maxlinkhdr; + rbp = (struct bootp_t *)m->m_data; + m->m_data += sizeof(struct udpiphdr); + memset(rbp, 0, sizeof(struct bootp_t)); + + bc = get_new_addr(&daddr.sin_addr); + if (!bc) { + dprintf("no address left\n"); + return; + } + dprintf("offered addr=%08x\n", ntohl(daddr.sin_addr.s_addr)); + + saddr.sin_addr.s_addr = htonl(ntohl(special_addr.s_addr) | CTL_ALIAS); + saddr.sin_port = htons(BOOTP_SERVER); + + daddr.sin_port = htons(BOOTP_CLIENT); + + rbp->bp_op = BOOTP_REPLY; + rbp->bp_xid = bp->bp_xid; + rbp->bp_htype = 1; + rbp->bp_hlen = 6; + memcpy(rbp->bp_hwaddr, bp->bp_hwaddr, 6); + + rbp->bp_yiaddr = daddr.sin_addr; /* IP address */ + + q = rbp->bp_vend; + memcpy(q, rfc1533_cookie, 4); + q += 4; + + if (dhcp_msg_type == DHCPDISCOVER) { + *q++ = RFC2132_MSG_TYPE; + *q++ = 1; + *q++ = DHCPOFFER; + } else if (dhcp_msg_type == DHCPREQUEST) { + *q++ = RFC2132_MSG_TYPE; + *q++ = 1; + *q++ = DHCPACK; + } + + if (dhcp_msg_type == DHCPDISCOVER || + dhcp_msg_type == DHCPREQUEST) { + *q++ = RFC2132_SRV_ID; + *q++ = 4; + memcpy(q, &saddr.sin_addr, 4); + q += 4; + + *q++ = RFC1533_NETMASK; + *q++ = 4; + *q++ = 0xff; + *q++ = 0xff; + *q++ = 0xff; + *q++ = 0x00; + + *q++ = RFC1533_GATEWAY; + *q++ = 4; + memcpy(q, &saddr.sin_addr, 4); + q += 4; + + *q++ = RFC1533_DNS; + *q++ = 4; + dns_addr.s_addr = htonl(ntohl(special_addr.s_addr) | CTL_DNS); + memcpy(q, &dns_addr, 4); + q += 4; + + *q++ = RFC2132_LEASE_TIME; + *q++ = 4; + val = htonl(LEASE_TIME); + memcpy(q, &val, 4); + q += 4; + } + *q++ = RFC1533_END; + + m->m_len = sizeof(struct bootp_t); + udp_output2(NULL, m, &saddr, &daddr, IPTOS_LOWDELAY); +} + +void bootp_input(struct mbuf *m) +{ + struct bootp_t *bp = (struct bootp_t *)m->m_data; + + if (bp->bp_op == BOOTP_REQUEST) { + bootp_reply(bp); + } +} |