diff options
Diffstat (limited to 'slirp/bootp.c')
| -rw-r--r-- | slirp/bootp.c | 127 |
1 files changed, 93 insertions, 34 deletions
diff --git a/slirp/bootp.c b/slirp/bootp.c index ca177f40c2..8a97660abc 100644 --- a/slirp/bootp.c +++ b/slirp/bootp.c @@ -66,6 +66,24 @@ static BOOTPClient *get_new_addr(struct in_addr *paddr) return bc; } +static BOOTPClient *request_addr(const struct in_addr *paddr, + const uint8_t *macaddr) +{ + uint32_t req_addr = ntohl(paddr->s_addr); + uint32_t spec_addr = ntohl(special_addr.s_addr); + 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(struct in_addr *paddr, const uint8_t *macaddr) { BOOTPClient *bc; @@ -83,18 +101,17 @@ static BOOTPClient *find_addr(struct in_addr *paddr, const uint8_t *macaddr) return bc; } -static void dhcp_decode(const uint8_t *buf, int size, - int *pmsg_type) +static void dhcp_decode(const struct bootp_t *bp, int *pmsg_type, + const struct in_addr **preq_addr) { const uint8_t *p, *p_end; int len, tag; *pmsg_type = 0; + *preq_addr = NULL; - p = buf; - p_end = buf + size; - if (size < 5) - return; + p = bp->bp_vend; + p_end = p + DHCP_OPT_LEN; if (memcmp(p, rfc1533_cookie, 4) != 0) return; p += 4; @@ -109,34 +126,46 @@ static void dhcp_decode(const uint8_t *buf, int size, if (p >= p_end) break; len = *p++; - dprintf("dhcp: tag=0x%02x len=%d\n", tag, len); + 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 = (struct in_addr *)p; + break; default: break; } p += len; } } + if (*pmsg_type == DHCPREQUEST && !*preq_addr && bp->bp_ciaddr.s_addr) { + *preq_addr = &bp->bp_ciaddr; + } } -static void bootp_reply(struct bootp_t *bp) +static void bootp_reply(const struct bootp_t *bp) { - BOOTPClient *bc; + BOOTPClient *bc = NULL; struct mbuf *m; struct bootp_t *rbp; struct sockaddr_in saddr, daddr; struct in_addr dns_addr; + const struct in_addr *preq_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); + 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->s_addr)); + else + dprintf("\n"); if (dhcp_msg_type == 0) dhcp_msg_type = DHCPREQUEST; /* Force reply for old BOOTP clients */ @@ -155,13 +184,29 @@ static void bootp_reply(struct bootp_t *bp) memset(rbp, 0, sizeof(struct bootp_t)); if (dhcp_msg_type == DHCPDISCOVER) { - new_addr: - bc = get_new_addr(&daddr.sin_addr); + if (preq_addr) { + bc = request_addr(preq_addr, client_ethaddr); + if (bc) { + daddr.sin_addr = *preq_addr; + } + } if (!bc) { - dprintf("no address left\n"); - return; + new_addr: + bc = get_new_addr(&daddr.sin_addr); + 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) { + daddr.sin_addr = *preq_addr; + memcpy(bc->macaddr, client_ethaddr, 6); + } else { + daddr.sin_addr.s_addr = 0; + } } else { bc = find_addr(&daddr.sin_addr, bp->bp_hwaddr); if (!bc) { @@ -171,12 +216,6 @@ static void bootp_reply(struct bootp_t *bp) } } - if (bootp_filename) - snprintf((char *)rbp->bp_file, sizeof(rbp->bp_file), "%s", - bootp_filename); - - 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); @@ -191,24 +230,29 @@ static void bootp_reply(struct bootp_t *bp) rbp->bp_yiaddr = daddr.sin_addr; /* Client IP address */ rbp->bp_siaddr = saddr.sin_addr; /* Server IP address */ - daddr.sin_addr.s_addr = 0xffffffffu; - 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 (bc) { + dprintf("%s addr=%08x\n", + (dhcp_msg_type == DHCPDISCOVER) ? "offered" : "ack'ed", + ntohl(daddr.sin_addr.s_addr)); + + 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); - if (dhcp_msg_type == DHCPDISCOVER || - dhcp_msg_type == DHCPREQUEST) { *q++ = RFC2132_SRV_ID; *q++ = 4; memcpy(q, &saddr.sin_addr, 4); @@ -247,9 +291,24 @@ static void bootp_reply(struct bootp_t *bp) memcpy(q, slirp_hostname, val); q += val; } + } else { + static const char nak_msg[] = "requested address not available"; + + dprintf("nak'ed addr=%08x\n", ntohl(preq_addr->s_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; + daddr.sin_addr.s_addr = 0xffffffffu; + m->m_len = sizeof(struct bootp_t) - sizeof(struct ip) - sizeof(struct udphdr); udp_output2(NULL, m, &saddr, &daddr, IPTOS_LOWDELAY); |