1 files changed, 301 insertions, 0 deletions
diff --git a/usr/kinit/ipconfig/dhcp_proto.c b/usr/kinit/ipconfig/dhcp_proto.c
new file mode 100644
index 0000000..4e560b8
--- /dev/null
+++ b/usr/kinit/ipconfig/dhcp_proto.c
@@ -0,0 +1,301 @@
+/*
+ * DHCP RFC 2131 and 2132
+ */
+#include <sys/types.h>
+#include <sys/uio.h>
+#include <netinet/in.h>
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+
+#include "ipconfig.h"
+#include "netdev.h"
+#include "bootp_packet.h"
+#include "bootp_proto.h"
+#include "dhcp_proto.h"
+#include "packet.h"
+
+static uint8_t dhcp_params[] = {
+	1,			/* subnet mask */
+	3,			/* default gateway */
+	6,			/* DNS server */
+	12,			/* host name */
+	15,			/* domain name */
+	17,			/* root path */
+	26,			/* interface mtu */
+	28,			/* broadcast addr */
+	40,			/* NIS domain name (why?) */
+	119,			/* Domain Search Option */
+	121,			/* Classless Static Route Option (RFC3442) */
+};
+
+static uint8_t dhcp_discover_hdr[] = {
+	99, 130, 83, 99,		/* bootp cookie */
+	53, 1, DHCPDISCOVER,		/* dhcp message type */
+	55, sizeof(dhcp_params),	/* parameter list */
+};
+
+static uint8_t dhcp_request_hdr[] = {
+	99, 130, 83, 99,		/* boot cookie */
+	53, 1, DHCPREQUEST,		/* dhcp message type */
+#define SERVER_IP_OFF 9
+	54, 4, 0, 0, 0, 0,		/* server IP */
+#define REQ_IP_OFF 15
+	50, 4, 0, 0, 0, 0,		/* requested IP address */
+	55, sizeof(dhcp_params),	/* parameter list */
+};
+
+static uint8_t dhcp_end[] = {
+	255,
+};
+
+/* Both iovecs below have to have the same structure, since dhcp_send()
+   pokes at the internals */
+#define DHCP_IOV_LEN 8
+
+static struct iovec dhcp_discover_iov[DHCP_IOV_LEN] = {
+	/* [0] = ip + udp header */
+	/* [1] = bootp header */
+	[2] = {dhcp_discover_hdr, sizeof(dhcp_discover_hdr)},
+	[3] = {dhcp_params, sizeof(dhcp_params)},
+	/* [4] = optional vendor class */
+	/* [5] = optional hostname */
+	/* [6] = {dhcp_end, sizeof(dhcp_end)} */
+	/* [7] = optional padding */
+};
+
+static struct iovec dhcp_request_iov[DHCP_IOV_LEN] = {
+	/* [0] = ip + udp header */
+	/* [1] = bootp header */
+	[2] = {dhcp_request_hdr, sizeof(dhcp_request_hdr)},
+	[3] = {dhcp_params, sizeof(dhcp_params)},
+	/* [4] = optional vendor class */
+	/* [5] = optional hostname */
+	/* [6] = {dhcp_end, sizeof(dhcp_end)} */
+	/* [7] = optional padding */
+};
+
+/*
+ * Parse a DHCP response packet
+ * Returns:
+ * 0 = Unexpected packet, not parsed
+ * 2 = DHCPOFFER (from dhcp_proto.h)
+ * 5 = DHCPACK
+ * 6 = DHCPNACK
+ */
+static int dhcp_parse(struct netdev *dev, struct bootp_hdr *hdr,
+		      uint8_t *exts, int extlen)
+{
+	uint8_t type = 0;
+	uint32_t serverid = INADDR_NONE;
+	uint32_t leasetime = 0;
+	int ret = 0;
+
+	if (extlen >= 4 && exts[0] == 99 && exts[1] == 130 &&
+	    exts[2] == 83 && exts[3] == 99) {
+		uint8_t *ext;
+
+		for (ext = exts + 4; ext - exts < extlen;) {
+			int len;
+			uint8_t opt = *ext++;
+
+			if (opt == 0)
+				continue;
+			else if (opt == 255)
+				break;
+
+			if (ext - exts >= extlen)
+				break;
+			len = *ext++;
+
+			if (ext - exts + len > extlen)
+				break;
+			switch (opt) {
+			case 51:	/* IP Address Lease Time */
+				if (len == 4)
+					leasetime = ntohl(*(uint32_t *)ext);
+				break;
+			case 53:	/* DHCP Message Type */
+				if (len == 1)
+					type = *ext;
+				break;
+			case 54:	/* Server Identifier */
+				if (len == 4)
+					memcpy(&serverid, ext, 4);
+				break;
+			}
+			ext += len;
+		}
+	}
+
+	switch (type) {
+	case DHCPOFFER:
+		ret = bootp_parse(dev, hdr, exts, extlen) ? DHCPOFFER : 0;
+		if (ret == DHCPOFFER && serverid != INADDR_NONE)
+			dev->serverid = serverid;
+		dprintf("\n   dhcp offer\n");
+		break;
+
+	case DHCPACK:
+		dev->dhcpleasetime = leasetime;
+		ret = bootp_parse(dev, hdr, exts, extlen) ? DHCPACK : 0;
+		dprintf("\n   dhcp ack\n");
+		break;
+
+	case DHCPNAK:
+		ret = DHCPNAK;
+		dprintf("\n   dhcp nak\n");
+		break;
+	}
+	return ret;
+}
+
+/*
+ * Receive and parse a DHCP packet
+ * Returns:
+ *-1 = Error in packet_recv, try again later
+ * 0 = Unexpected packet, discarded
+ * 2 = DHCPOFFER (from dhcp_proto.h)
+ * 5 = DHCPACK
+ * 6 = DHCPNACK
+ */
+static int dhcp_recv(struct netdev *dev)
+{
+	struct bootp_hdr bootp;
+	uint8_t dhcp_options[BOOTP_EXTS_SIZE];
+	struct iovec iov[] = {
+		/* [0] = ip + udp header */
+		[1] = {&bootp, sizeof(struct bootp_hdr)},
+		[2] = {dhcp_options, sizeof(dhcp_options)}
+	};
+	int ret;
+
+	ret = packet_recv(dev, iov, 3);
+	if (ret <= 0)
+		return ret;
+
+	dprintf("\n   dhcp xid %08x ", dev->bootp.xid);
+
+	if (ret < sizeof(struct bootp_hdr) || bootp.op != BOOTP_REPLY ||
+	    /* RFC951 7.5 */ bootp.xid != dev->bootp.xid ||
+	    memcmp(bootp.chaddr, dev->hwaddr, 16))
+		return 0;
+
+	ret -= sizeof(struct bootp_hdr);
+
+	return dhcp_parse(dev, &bootp, dhcp_options, ret);
+}
+
+static int dhcp_send(struct netdev *dev, struct iovec *vec)
+{
+	struct bootp_hdr bootp;
+	char dhcp_hostname[SYS_NMLN+2];
+	uint8_t padding[BOOTP_MIN_LEN - sizeof(struct bootp_hdr)];
+	int padding_len;
+	int i = 4;
+	int j;
+
+	memset(&bootp, 0, sizeof(struct bootp_hdr));
+
+	bootp.op	= BOOTP_REQUEST;
+	bootp.htype	= dev->hwtype;
+	bootp.hlen	= dev->hwlen;
+	bootp.xid	= dev->bootp.xid;
+	bootp.ciaddr	= INADDR_ANY;
+	/* yiaddr should always be set to 0 for the messages we're likely
+	 * to send as a DHCP client: DHCPDISCOVER, DHCPREQUEST, DHCPDECLINE,
+	 * DHCPINFORM, DHCPRELEASE
+	 * cf. RFC2131 section 4.1.1, table 5.
+	 */
+	bootp.yiaddr	= INADDR_ANY;
+	bootp.giaddr	= INADDR_ANY;
+	bootp.flags	= htons(0x8000);
+	bootp.secs	= htons(time(NULL) - dev->open_time);
+	memcpy(bootp.chaddr, dev->hwaddr, 16);
+
+	vec[1].iov_base	= &bootp;
+	vec[1].iov_len	= sizeof(struct bootp_hdr);
+
+	dprintf("xid %08x secs %d ", bootp.xid, ntohs(bootp.secs));
+
+	if (vendor_class_identifier_len > 2) {
+		vec[i].iov_base = vendor_class_identifier;
+		vec[i].iov_len  = vendor_class_identifier_len;
+		i++;
+
+		dprintf("vendor_class_identifier \"%.*s\" ",
+			vendor_class_identifier_len-2,
+			vendor_class_identifier+2);
+	}
+
+	if (dev->reqhostname[0] != '\0') {
+		int len = strlen(dev->reqhostname);
+		dhcp_hostname[0] = 12;
+		dhcp_hostname[1] = len;
+		memcpy(dhcp_hostname+2, dev->reqhostname, len);
+
+		vec[i].iov_base = dhcp_hostname;
+		vec[i].iov_len  = len+2;
+		i++;
+
+		printf("hostname %.*s ", len, dhcp_hostname+2);
+	}
+
+	vec[i].iov_base = dhcp_end;
+	vec[i].iov_len  = sizeof(dhcp_end);
+
+	/* Append padding if DHCP packet length is shorter than BOOTP_MIN_LEN */
+	padding_len = sizeof(padding);
+	for (j = 2; j <= i; j++)
+		padding_len -= vec[j].iov_len;
+	if (padding_len > 0) {
+		memset(padding, 0, padding_len);
+		i++;
+		vec[i].iov_base = padding;
+		vec[i].iov_len  = padding_len;
+	}
+
+	return packet_send(dev, vec, i + 1);
+}
+
+/*
+ * Send a DHCP discover packet
+ */
+int dhcp_send_discover(struct netdev *dev)
+{
+	dev->ip_addr = INADDR_ANY;
+	dev->ip_gateway = INADDR_ANY;
+
+	dprintf("-> dhcp discover ");
+
+	return dhcp_send(dev, dhcp_discover_iov);
+}
+
+/*
+ * Receive a DHCP offer packet
+ */
+int dhcp_recv_offer(struct netdev *dev)
+{
+	return dhcp_recv(dev);
+}
+
+/*
+ * Send a DHCP request packet
+ */
+int dhcp_send_request(struct netdev *dev)
+{
+	memcpy(&dhcp_request_hdr[SERVER_IP_OFF], &dev->serverid, 4);
+	memcpy(&dhcp_request_hdr[REQ_IP_OFF], &dev->ip_addr, 4);
+
+	dprintf("-> dhcp request ");
+
+	return dhcp_send(dev, dhcp_request_iov);
+}
+
+/*
+ * Receive a DHCP ack packet
+ */
+int dhcp_recv_ack(struct netdev *dev)
+{
+	return dhcp_recv(dev);
+}