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Diffstat (limited to 'usr/kinit/ipconfig/bootp_proto.c')
-rw-r--r--usr/kinit/ipconfig/bootp_proto.c565
1 files changed, 565 insertions, 0 deletions
diff --git a/usr/kinit/ipconfig/bootp_proto.c b/usr/kinit/ipconfig/bootp_proto.c
new file mode 100644
index 0000000..f6f9dd4
--- /dev/null
+++ b/usr/kinit/ipconfig/bootp_proto.c
@@ -0,0 +1,565 @@
+/*
+ * BOOTP packet protocol handling.
+ */
+#include <sys/types.h>
+#include <sys/uio.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+#include <netinet/in.h>
+
+#include "ipconfig.h"
+#include "netdev.h"
+#include "bootp_packet.h"
+#include "bootp_proto.h"
+#include "packet.h"
+
+static uint8_t bootp_options[312] = {
+ [ 0] = 99, 130, 83, 99,/* RFC1048 magic cookie */
+ [ 4] = 1, 4, /* 4- 9 subnet mask */
+ [ 10] = 3, 4, /* 10- 15 default gateway */
+ [ 16] = 5, 8, /* 16- 25 nameserver */
+ [ 26] = 12, 32, /* 26- 59 host name */
+ [ 60] = 40, 32, /* 60- 95 nis domain name */
+ [ 96] = 17, 40, /* 96-137 boot path */
+ [138] = 57, 2, 1, 150, /* 138-141 extension buffer */
+ [142] = 255, /* end of list */
+};
+
+/*
+ * Send a plain bootp request packet with options
+ */
+int bootp_send_request(struct netdev *dev)
+{
+ struct bootp_hdr bootp;
+ struct iovec iov[] = {
+ /* [0] = ip + udp headers */
+ [1] = {&bootp, sizeof(bootp)},
+ [2] = {bootp_options, 312}
+ };
+
+ 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 = dev->ip_addr;
+ bootp.secs = htons(time(NULL) - dev->open_time);
+ memcpy(bootp.chaddr, dev->hwaddr, 16);
+
+ dprintf("-> bootp xid 0x%08x secs 0x%08x ",
+ bootp.xid, ntohs(bootp.secs));
+
+ return packet_send(dev, iov, 2);
+}
+
+/*
+ * DESCRIPTION
+ * bootp_ext119_decode() decodes Domain Search Option data.
+ * The decoded string is separated with ' '.
+ * For example, it is either "foo.bar.baz. bar.baz.", "foo.bar.", or "foo.".
+ *
+ * ARGUMENTS
+ * const uint8_t *ext
+ * *ext is a pointer to a DHCP Domain Search Option data. *ext does not
+ * include a tag(code) octet and a length octet in DHCP options.
+ * For example, if *ext is {3, 'f', 'o', 'o', 0}, this function returns
+ * a pointer to a "foo." string.
+ *
+ * int16_t ext_size
+ * ext_size is the memory size of *ext. For example,
+ * if *ext is {3, 'f', 'o', 'o', 0}, ext_size must be 5.
+ *
+ * uint8_t *tmp
+ * *tmp is a pointer to a temporary memory space for decoding.
+ * The memory size must be equal to or more than ext_size.
+ * 'memset(tmp, 0, sizeof(tmp));' is not required, but values in *tmp
+ * are changed in decoding process.
+ *
+ * RETURN VALUE
+ * if OK, a pointer to a decoded string malloc-ed
+ * else , NULL
+ *
+ * SEE ALSO RFC3397
+ */
+static char *bootp_ext119_decode(const void *ext, int16_t ext_size, void *tmp)
+{
+ uint8_t *u8ext;
+ int_fast32_t i;
+ int_fast32_t decoded_size;
+ int_fast8_t currentdomain_is_singledot;
+
+ /* only for validating *ext */
+ uint8_t *is_pointee;
+ int_fast32_t is_pointee_size;
+
+ /* only for structing a decoded string */
+ char *decoded_str;
+ int_fast32_t dst_i;
+
+ if (ext == NULL || ext_size <= 0 || tmp == NULL)
+ return NULL;
+
+ u8ext = (uint8_t *)ext;
+ is_pointee = tmp;
+ memset(is_pointee, 0, (size_t)ext_size);
+ is_pointee_size = 0;
+
+ /*
+ * validate the format of *ext and
+ * calculate the memory size for a decoded string
+ */
+ i = 0;
+ decoded_size = 0;
+ currentdomain_is_singledot = 1;
+ while (1) {
+ if (i >= ext_size)
+ return NULL;
+
+ if (u8ext[i] == 0) {
+ /* Zero-ending */
+ if (currentdomain_is_singledot)
+ decoded_size++; /* for '.' */
+ decoded_size++; /* for ' ' or '\0' */
+ currentdomain_is_singledot = 1;
+ i++;
+ if (i == ext_size)
+ break;
+ is_pointee_size = i;
+ } else if (u8ext[i] < 0x40) {
+ /* Label(sub-domain string) */
+ int j;
+
+ /* loosely validate characters for domain names */
+ if (i + u8ext[i] >= ext_size)
+ return NULL;
+ for (j = i + 1; j <= i + u8ext[i]; j++)
+ if (!(u8ext[j] == '-' ||
+ ('0' <= u8ext[j] && u8ext[j] <= '9') ||
+ ('A' <= u8ext[j] && u8ext[j] <= 'Z') ||
+ ('a' <= u8ext[j] && u8ext[j] <= 'z')))
+ return NULL;
+
+ is_pointee[i] = 1;
+ decoded_size += u8ext[i] + 1; /* for Label + '.' */
+ currentdomain_is_singledot = 0;
+ i += u8ext[i] + 1;
+ } else if (u8ext[i] < 0xc0)
+ return NULL;
+
+ else {
+ /* Compression-pointer (to a prior Label) */
+ int_fast32_t p;
+
+ if (i + 1 >= ext_size)
+ return NULL;
+
+ p = ((0x3f & u8ext[i]) << 8) + u8ext[i + 1];
+ if (!(p < is_pointee_size && is_pointee[p]))
+ return NULL;
+
+ while (1) {
+ /* u8ext[p] was validated */
+ if (u8ext[p] == 0) {
+ /* Zero-ending */
+ decoded_size++;
+ break;
+ } else if (u8ext[p] < 0x40) {
+ /* Label(sub-domain string) */
+ decoded_size += u8ext[p] + 1;
+ p += u8ext[p] + 1;
+ } else {
+ /* Compression-pointer */
+ p = ((0x3f & u8ext[p]) << 8)
+ + u8ext[p + 1];
+ }
+ }
+
+ currentdomain_is_singledot = 1;
+ i += 2;
+ if (i == ext_size)
+ break;
+ is_pointee_size = i;
+ }
+ }
+
+
+ /*
+ * construct a decoded string
+ */
+ decoded_str = malloc(decoded_size);
+ if (decoded_str == NULL)
+ return NULL;
+
+ i = 0;
+ dst_i = 0;
+ currentdomain_is_singledot = 1;
+ while (1) {
+ if (u8ext[i] == 0) {
+ /* Zero-ending */
+ if (currentdomain_is_singledot) {
+ if (dst_i != 0)
+ dst_i++;
+ decoded_str[dst_i] = '.';
+ }
+ dst_i++;
+ decoded_str[dst_i] = ' ';
+
+ currentdomain_is_singledot = 1;
+ i++;
+ if (i == ext_size)
+ break;
+ } else if (u8ext[i] < 0x40) {
+ /* Label(sub-domain string) */
+ if (dst_i != 0)
+ dst_i++;
+ memcpy(&decoded_str[dst_i], &u8ext[i + 1],
+ (size_t)u8ext[i]);
+ dst_i += u8ext[i];
+ decoded_str[dst_i] = '.';
+
+ currentdomain_is_singledot = 0;
+ i += u8ext[i] + 1;
+ } else {
+ /* Compression-pointer (to a prior Label) */
+ int_fast32_t p;
+
+ p = ((0x3f & u8ext[i]) << 8) + u8ext[i + 1];
+ while (1) {
+ if (u8ext[p] == 0) {
+ /* Zero-ending */
+ decoded_str[dst_i++] = '.';
+ decoded_str[dst_i] = ' ';
+ break;
+ } else if (u8ext[p] < 0x40) {
+ /* Label(sub-domain string) */
+ dst_i++;
+ memcpy(&decoded_str[dst_i],
+ &u8ext[p + 1],
+ (size_t)u8ext[p]);
+ dst_i += u8ext[p];
+ decoded_str[dst_i] = '.';
+
+ p += u8ext[p] + 1;
+ } else {
+ /* Compression-pointer */
+ p = ((0x3f & u8ext[p]) << 8)
+ + u8ext[p + 1];
+ }
+ }
+
+ currentdomain_is_singledot = 1;
+ i += 2;
+ if (i == ext_size)
+ break;
+ }
+ }
+ decoded_str[dst_i] = '\0';
+#ifdef DEBUG
+ if (dst_i + 1 != decoded_size) {
+ dprintf("bug:%s():bottom: malloc(%ld), write(%ld)\n",
+ __func__, (long)decoded_size, (long)(dst_i + 1));
+ exit(1);
+ }
+#endif
+ return decoded_str;
+}
+
+/*
+ * DESCRIPTION
+ * bootp_ext121_decode() decodes Classless Route Option data.
+ *
+ * ARGUMENTS
+ * const uint8_t *ext
+ * *ext is a pointer to a DHCP Classless Route Option data.
+ * For example, if *ext is {16, 192, 168, 192, 168, 42, 1},
+ * this function returns a pointer to
+ * {
+ * subnet = 192.168.0.0;
+ * netmask_width = 16;
+ * gateway = 192.168.42.1;
+ * next = NULL;
+ * }
+ *
+ * int16_t ext_size
+ * ext_size is the memory size of *ext. For example,
+ * if *ext is {16, 192, 168, 192, 168, 42, 1}, ext_size must be 7.
+ *
+ * RETURN VALUE
+ * if OK, a pointer to a decoded struct route malloc-ed
+ * else , NULL
+ *
+ * SEE ALSO RFC3442
+ */
+struct route *bootp_ext121_decode(const uint8_t *ext, int16_t ext_size)
+{
+ int16_t index = 0;
+ uint8_t netmask_width;
+ uint8_t significant_octets;
+ struct route *routes = NULL;
+ struct route *prev_route = NULL;
+
+ while (index < ext_size) {
+ netmask_width = ext[index];
+ index++;
+ if (netmask_width > 32) {
+ printf("IP-Config: Given Classless Route Option subnet mask width '%u' "
+ "exceeds IPv4 limit of 32. Ignoring remaining option.\n",
+ netmask_width);
+ return routes;
+ }
+ significant_octets = netmask_width / 8 + (netmask_width % 8 > 0);
+ if (ext_size - index < significant_octets + 4) {
+ printf("IP-Config: Given Classless Route Option remaining lengths (%u octets) "
+ "is shorter than the expected %u octets. Ignoring remaining options.\n",
+ ext_size - index, significant_octets + 4);
+ return routes;
+ }
+
+ struct route *route = malloc(sizeof(struct route));
+ if (route == NULL)
+ return routes;
+
+ /* convert only significant octets from byte array into integer in network byte order */
+ route->subnet = 0;
+ memcpy(&route->subnet, &ext[index], significant_octets);
+ index += significant_octets;
+ /* RFC3442 demands: After deriving a subnet number and subnet mask from
+ each destination descriptor, the DHCP client MUST zero any bits in
+ the subnet number where the corresponding bit in the mask is zero. */
+ route->subnet &= netdev_genmask(netmask_width);
+
+ /* convert octet array into network byte order */
+ memcpy(&route->gateway, &ext[index], 4);
+ index += 4;
+
+ route->netmask_width = netmask_width;
+ route->next = NULL;
+
+ if (prev_route == NULL) {
+ routes = route;
+ } else {
+ prev_route->next = route;
+ }
+ prev_route = route;
+ }
+ return routes;
+}
+
+/*
+ * Parse a bootp reply packet
+ */
+int bootp_parse(struct netdev *dev, struct bootp_hdr *hdr,
+ uint8_t *exts, int extlen)
+{
+ uint8_t ext119_buf[BOOTP_EXTS_SIZE];
+ int16_t ext119_len = 0;
+ uint8_t ext121_buf[BOOTP_EXTS_SIZE];
+ int16_t ext121_len = 0;
+
+ dev->bootp.gateway = hdr->giaddr;
+ dev->ip_addr = hdr->yiaddr;
+ dev->ip_server = hdr->siaddr;
+ dev->ip_netmask = INADDR_ANY;
+ dev->ip_broadcast = INADDR_ANY;
+ dev->ip_gateway = hdr->giaddr;
+ dev->ip_nameserver[0] = INADDR_ANY;
+ dev->ip_nameserver[1] = INADDR_ANY;
+ dev->hostname[0] = '\0';
+ dev->nisdomainname[0] = '\0';
+ dev->bootpath[0] = '\0';
+ memcpy(&dev->filename, &hdr->boot_file, FNLEN);
+
+ 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 1: /* subnet mask */
+ if (len == 4)
+ memcpy(&dev->ip_netmask, ext, 4);
+ break;
+ case 3: /* default gateway */
+ if (len >= 4)
+ memcpy(&dev->ip_gateway, ext, 4);
+ break;
+ case 6: /* DNS server */
+ if (len >= 4)
+ memcpy(&dev->ip_nameserver, ext,
+ len >= 8 ? 8 : 4);
+ break;
+ case 12: /* host name */
+ if (len > sizeof(dev->hostname) - 1)
+ len = sizeof(dev->hostname) - 1;
+ memcpy(&dev->hostname, ext, len);
+ dev->hostname[len] = '\0';
+ break;
+ case 15: /* domain name */
+ if (len > sizeof(dev->dnsdomainname) - 1)
+ len = sizeof(dev->dnsdomainname) - 1;
+ memcpy(&dev->dnsdomainname, ext, len);
+ dev->dnsdomainname[len] = '\0';
+ break;
+ case 17: /* root path */
+ if (len > sizeof(dev->bootpath) - 1)
+ len = sizeof(dev->bootpath) - 1;
+ memcpy(&dev->bootpath, ext, len);
+ dev->bootpath[len] = '\0';
+ break;
+ case 26: /* interface MTU */
+ if (len == 2)
+ dev->mtu = (ext[0] << 8) + ext[1];
+ break;
+ case 28: /* broadcast addr */
+ if (len == 4)
+ memcpy(&dev->ip_broadcast, ext, 4);
+ break;
+ case 40: /* NIS domain name */
+ if (len > sizeof(dev->nisdomainname) - 1)
+ len = sizeof(dev->nisdomainname) - 1;
+ memcpy(&dev->nisdomainname, ext, len);
+ dev->nisdomainname[len] = '\0';
+ break;
+ case 54: /* server identifier */
+ if (len == 4 && !dev->ip_server)
+ memcpy(&dev->ip_server, ext, 4);
+ break;
+ case 119: /* Domain Search Option */
+ if (ext119_len >= 0 &&
+ ext119_len + len <= sizeof(ext119_buf)) {
+ memcpy(ext119_buf + ext119_len,
+ ext, len);
+ ext119_len += len;
+ } else
+ ext119_len = -1;
+
+ break;
+ case 121: /* Classless Static Route Option (RFC3442) */
+ if (ext121_len >= 0 &&
+ ext121_len + len <= sizeof(ext121_buf)) {
+ memcpy(ext121_buf + ext121_len,
+ ext, len);
+ ext121_len += len;
+ } else
+ ext121_len = -1;
+
+ break;
+ }
+
+ ext += len;
+ }
+ }
+ if (ext119_len > 0) {
+ char *ret;
+ uint8_t ext119_tmp[BOOTP_EXTS_SIZE];
+
+ ret = bootp_ext119_decode(ext119_buf, ext119_len, ext119_tmp);
+ if (ret != NULL) {
+ if (dev->domainsearch != NULL)
+ free(dev->domainsearch);
+ dev->domainsearch = ret;
+ }
+ }
+
+ if (ext121_len > 0) {
+ struct route *ret;
+
+ ret = bootp_ext121_decode(ext121_buf, ext121_len);
+ if (ret != NULL) {
+ struct route *cur = dev->routes;
+ struct route *next;
+ while (cur != NULL) {
+ next = cur->next;
+ free(cur);
+ cur = next;
+ }
+ dev->routes = ret;
+ }
+ }
+
+ /*
+ * Got packet.
+ */
+ return 1;
+}
+
+/*
+ * Receive a bootp reply and parse packet
+ * Returns:
+ *-1 = Error in packet_recv, try again later
+ * 0 = Unexpected packet, discarded
+ * 1 = Correctly received and parsed packet
+ */
+int bootp_recv_reply(struct netdev *dev)
+{
+ struct bootp_hdr bootp;
+ uint8_t bootp_options[BOOTP_EXTS_SIZE];
+ struct iovec iov[] = {
+ /* [0] = ip + udp headers */
+ [1] = {&bootp, sizeof(struct bootp_hdr)},
+ [2] = {bootp_options, sizeof(bootp_options)}
+ };
+ int ret;
+
+ ret = packet_recv(dev, iov, 3);
+ if (ret <= 0)
+ return ret;
+
+ 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 bootp_parse(dev, &bootp, bootp_options, ret);
+}
+
+/*
+ * Initialise interface for bootp.
+ */
+int bootp_init_if(struct netdev *dev)
+{
+ short flags;
+
+ /*
+ * Get the device flags
+ */
+ if (netdev_getflags(dev, &flags))
+ return -1;
+
+ /*
+ * We can't do DHCP nor BOOTP if this device
+ * doesn't support broadcast.
+ */
+ if (dev->mtu < 364 || (flags & IFF_BROADCAST) == 0) {
+ dev->caps &= ~(CAP_BOOTP | CAP_DHCP);
+ return 0;
+ }
+
+ /*
+ * Get a random XID
+ */
+ dev->bootp.xid = (uint32_t) lrand48();
+ dev->open_time = time(NULL);
+
+ return 0;
+}
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