diff options
Diffstat (limited to 'slirp-android/bootp.c')
| -rw-r--r-- | slirp-android/bootp.c | 330 |
1 files changed, 330 insertions, 0 deletions
diff --git a/slirp-android/bootp.c b/slirp-android/bootp.c new file mode 100644 index 0000000..814b030 --- /dev/null +++ b/slirp-android/bootp.c @@ -0,0 +1,330 @@ +/* + * 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> +#include "helper.h" + +/* XXX: only DHCP is supported */ + +#define NB_ADDR 16 + +#define START_ADDR 15 + +#define LEASE_TIME (24 * 3600) + +typedef struct { + uint8_t allocated; + uint8_t macaddr[6]; +} BOOTPClient; + +static BOOTPClient bootp_clients[NB_ADDR]; + +const char *bootp_filename; + +static const uint8_t rfc1533_cookie[] = { RFC1533_COOKIE }; + +#ifdef DEBUG +#define dprintf(fmt, ...) \ +if (slirp_debug & DBG_CALL) { fprintf(dfd, fmt, ## __VA_ARGS__); fflush(dfd); } +#else +#define dprintf(fmt, ...) +#endif + +static BOOTPClient *get_new_addr(SockAddress* paddr, + const uint8_t *macaddr) +{ + BOOTPClient *bc; + int i; + + for(i = 0; i < NB_ADDR; i++) { + bc = &bootp_clients[i]; + if (!bc->allocated || !memcmp(macaddr, bc->macaddr, 6)) + goto found; + } + return NULL; + found: + bc = &bootp_clients[i]; + bc->allocated = 1; + sock_address_init_inet( paddr, + special_addr_ip | (i+START_ADDR), + BOOTP_CLIENT ); + return bc; +} + +static BOOTPClient *request_addr(const ipaddr_t *paddr, + const uint8_t *macaddr) +{ + uint32_t req_addr = ip_geth(*paddr); + uint32_t spec_addr = special_addr_ip; + BOOTPClient *bc; + + if (req_addr >= (spec_addr | START_ADDR) && + req_addr < (spec_addr | (NB_ADDR + START_ADDR))) { + bc = &bootp_clients[(req_addr & 0xff) - START_ADDR]; + if (!bc->allocated || !memcmp(macaddr, bc->macaddr, 6)) { + bc->allocated = 1; + return bc; + } + } + return NULL; +} + +static BOOTPClient *find_addr(SockAddress *paddr, const uint8_t *macaddr) +{ + BOOTPClient *bc; + int i; + + for(i = 0; i < NB_ADDR; i++) { + if (!memcmp(macaddr, bootp_clients[i].macaddr, 6)) + goto found; + } + return NULL; + found: + bc = &bootp_clients[i]; + bc->allocated = 1; + sock_address_init_inet( paddr, + special_addr_ip | (i + START_ADDR), + BOOTP_CLIENT ); + return bc; +} + +static void dhcp_decode(const struct bootp_t *bp, int *pmsg_type, + const ipaddr_t **preq_addr) +{ + const uint8_t *p, *p_end; + int len, tag; + + *pmsg_type = 0; + *preq_addr = NULL; + + p = bp->bp_vend; + p_end = p + DHCP_OPT_LEN; + 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=%d len=%d\n", tag, len); + + switch(tag) { + case RFC2132_MSG_TYPE: + if (len >= 1) + *pmsg_type = p[0]; + break; + case RFC2132_REQ_ADDR: + if (len >= 4) + *preq_addr = (const ipaddr_t *)p; + break; + default: + break; + } + p += len; + } + } + if (*pmsg_type == DHCPREQUEST && !*preq_addr && bp->bp_ciaddr) { + *preq_addr = (const ipaddr_t*)&bp->bp_ciaddr; + } +} + +static void bootp_reply(const struct bootp_t *bp) +{ + BOOTPClient *bc = NULL; + struct mbuf *m; + struct bootp_t *rbp; + SockAddress saddr, daddr; + uint32_t dns_addr; + const ipaddr_t *preq_addr; + int dhcp_msg_type, val; + uint8_t *q; + + /* extract exact DHCP msg type */ + dhcp_decode(bp, &dhcp_msg_type, &preq_addr); + dprintf("bootp packet op=%d msgtype=%d", bp->bp_op, dhcp_msg_type); + if (preq_addr) { + dprintf(" req_addr=%08x\n", ntohl(*preq_addr)); + } else { + dprintf("\n"); + } + if (dhcp_msg_type == 0) + dhcp_msg_type = DHCPREQUEST; /* Force reply for old BOOTP clients */ + + 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)); + + if (dhcp_msg_type == DHCPDISCOVER) { + if (preq_addr) { + bc = request_addr(preq_addr, client_ethaddr); + if (bc) { + sock_address_init_inet(&daddr, ip_geth(*preq_addr), BOOTP_CLIENT); + } + } + if (!bc) { + new_addr: + bc = get_new_addr(&daddr, client_ethaddr); + if (!bc) { + dprintf("no address left\n"); + return; + } + } + memcpy(bc->macaddr, client_ethaddr, 6); + } else if (preq_addr) { + bc = request_addr(preq_addr, client_ethaddr); + if (bc) { + sock_address_init_inet(&daddr, ip_geth(*preq_addr), BOOTP_CLIENT); + memcpy(bc->macaddr, client_ethaddr, 6); + } else { + sock_address_init_inet(&daddr, 0, BOOTP_CLIENT); + } + } else { + bc = find_addr(&daddr, bp->bp_hwaddr); + if (!bc) { + /* if never assigned, behaves as if it was already + assigned (windows fix because it remembers its address) */ + goto new_addr; + } + } + + sock_address_init_inet( &saddr, special_addr_ip | CTL_ALIAS, + BOOTP_SERVER ); + + 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 = htonl(sock_address_get_ip(&daddr)); /* Client IP address */ + rbp->bp_siaddr = htonl(sock_address_get_ip(&saddr)); /* Server IP address */ + + q = rbp->bp_vend; + memcpy(q, rfc1533_cookie, 4); + q += 4; + + if (bc) { + uint32_t saddr_ip = htonl(sock_address_get_ip(&saddr)); + dprintf("%s addr=%08x\n", + (dhcp_msg_type == DHCPDISCOVER) ? "offered" : "ack'ed", + sock_address_get_ip(&daddr)); + + if (dhcp_msg_type == DHCPDISCOVER) { + *q++ = RFC2132_MSG_TYPE; + *q++ = 1; + *q++ = DHCPOFFER; + } else /* DHCPREQUEST */ { + *q++ = RFC2132_MSG_TYPE; + *q++ = 1; + *q++ = DHCPACK; + } + + if (bootp_filename) + snprintf((char *)rbp->bp_file, sizeof(rbp->bp_file), "%s", + bootp_filename); + + *q++ = RFC2132_SRV_ID; + *q++ = 4; + memcpy(q, &saddr_ip, 4); + q += 4; + + *q++ = RFC1533_NETMASK; + *q++ = 4; + *q++ = 0xff; + *q++ = 0xff; + *q++ = 0xff; + *q++ = 0x00; + + if (!slirp_restrict) { + *q++ = RFC1533_GATEWAY; + *q++ = 4; + memcpy(q, &saddr_ip, 4); + q += 4; + + *q++ = RFC1533_DNS; + *q++ = 4; + dns_addr = htonl(special_addr_ip | 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; + + if (*slirp_hostname) { + val = strlen(slirp_hostname); + *q++ = RFC1533_HOSTNAME; + *q++ = val; + memcpy(q, slirp_hostname, val); + q += val; + } + } else { + static const char nak_msg[] = "requested address not available"; + + dprintf("nak'ed addr=%08x\n", ip_geth(*preq_addr)); + + *q++ = RFC2132_MSG_TYPE; + *q++ = 1; + *q++ = DHCPNAK; + + *q++ = RFC2132_MESSAGE; + *q++ = sizeof(nak_msg) - 1; + memcpy(q, nak_msg, sizeof(nak_msg) - 1); + q += sizeof(nak_msg) - 1; + } + *q++ = RFC1533_END; + + sock_address_init_inet(&daddr, 0xffffffffu, BOOTP_CLIENT); + + m->m_len = sizeof(struct bootp_t) - + sizeof(struct ip) - sizeof(struct udphdr); + udp_output2_(NULL, m, &saddr, &daddr, IPTOS_LOWDELAY); +} + +void bootp_input(struct mbuf *m) +{ + struct bootp_t *bp = mtod(m, struct bootp_t *); + + if (bp->bp_op == BOOTP_REQUEST) { + bootp_reply(bp); + } +} |