#include "dhcpv4.h"
#include "dhcpv6.h"
-#define PACKET_SIZE(start, end) (((uint8_t *)end - (uint8_t *)start) < DHCPV4_MIN_PACKET_SIZE ? \
- DHCPV4_MIN_PACKET_SIZE : (uint8_t *)end - (uint8_t *)start)
#define MAX_PREFIX_LEN 28
static uint32_t serial = 0;
return dhcpv4_msg_names[req_msg];
}
-static void dhcpv4_put(struct dhcpv4_message *msg, uint8_t **cursor,
- uint8_t type, uint8_t len, const void *data)
+static ssize_t dhcpv4_send_reply(struct iovec *iov, size_t iov_len,
+ struct sockaddr *dest, socklen_t dest_len,
+ void *opaque)
{
- uint8_t *c = *cursor;
- uint8_t *end = (uint8_t *)msg + sizeof(*msg);
- bool tag_only = type == DHCPV4_OPT_PAD || type == DHCPV4_OPT_END;
- int total_len = tag_only ? 1 : 2 + len;
-
- if (*cursor + total_len > end)
- return;
-
- *cursor += total_len;
- *c++ = type;
-
- if (tag_only)
- return;
+ int *sock = opaque;
+ struct msghdr msg = {
+ .msg_name = dest,
+ .msg_namelen = dest_len,
+ .msg_iov = iov,
+ .msg_iovlen = iov_len,
+ };
- *c++ = len;
- memcpy(c, data, len);
+ return sendmsg(*sock, &msg, MSG_DONTWAIT);
}
static void dhcpv4_add_padding(struct iovec *iov, size_t iovlen)
iov[iovlen - 1].iov_len = DHCPV4_MIN_PACKET_SIZE - len;
}
+enum {
+ IOV_FR_HEADER = 0,
+ IOV_FR_MESSAGE,
+ IOV_FR_AUTH,
+ IOV_FR_AUTH_BODY,
+ IOV_FR_SERVERID,
+ IOV_FR_END,
+ IOV_FR_PADDING,
+ IOV_FR_TOTAL
+};
+
static void dhcpv4_fr_send(struct dhcp_assignment *a)
{
- struct dhcpv4_message fr_msg = {
+ struct dhcpv4_message fr = {
.op = DHCPV4_OP_BOOTREPLY,
.htype = ARPHRD_ETHER,
.hlen = ETH_ALEN,
.file = { 0 },
.cookie = htonl(DHCPV4_MAGIC_COOKIE),
};
- struct dhcpv4_auth_forcerenew *auth_o, auth = {
+ struct dhcpv4_option_u8 fr_msg = {
+ .code = DHCPV4_OPT_MESSAGE,
+ .len = sizeof(uint8_t),
+ .data = DHCPV4_MSG_FORCERENEW,
+ };
+ struct dhcpv4_auth_forcerenew fr_auth_body = {
.protocol = DHCPV4_AUTH_PROTO_RKAP,
.algorithm = DHCPV4_AUTH_ALG_HMAC_MD5,
.rdm = DHCPV4_AUTH_RDM_MONOTONIC,
- .replay = { htonl(time(NULL)), htonl(++serial) },
.type = DHCPV4_AUTH_RKAP_AI_TYPE_MD5_DIGEST,
.key = { 0 },
};
- struct interface *iface = a->iface;
- uint8_t *cursor = fr_msg.options;
- uint8_t msg = DHCPV4_MSG_FORCERENEW;
+ struct dhcpv4_option fr_auth = {
+ .code = DHCPV4_OPT_AUTHENTICATION,
+ .len = sizeof(fr_auth_body),
+ };
+ struct dhcpv4_option_u32 fr_serverid = {
+ .code = DHCPV4_OPT_SERVERID,
+ .len = sizeof(struct in_addr),
+ .data = a->fr_ip->addr.addr.in.s_addr,
+ };
+ uint8_t fr_end = DHCPV4_OPT_END;
+
+ struct iovec iov[IOV_FR_TOTAL] = {
+ [IOV_FR_HEADER] = { &fr, offsetof(typeof(fr), options) },
+ [IOV_FR_MESSAGE] = { &fr_msg, sizeof(fr_msg) },
+ [IOV_FR_AUTH] = { &fr_auth, 0 },
+ [IOV_FR_AUTH_BODY] = { &fr_auth_body, 0 },
+ [IOV_FR_SERVERID] = { &fr_serverid, 0 },
+ [IOV_FR_END] = { &fr_end, sizeof(fr_end) },
+ [IOV_FR_PADDING] = { NULL, 0 },
+ };
+
struct sockaddr_in dest = {
.sin_family = AF_INET,
.sin_port = htons(DHCPV4_CLIENT_PORT),
.sin_addr = { a->addr },
};
- odhcpd_urandom(&fr_msg.xid, sizeof(fr_msg.xid));
- memcpy(fr_msg.chaddr, a->hwaddr, fr_msg.hlen);
+ odhcpd_urandom(&fr.xid, sizeof(fr.xid));
+ memcpy(fr.chaddr, a->hwaddr, fr.hlen);
- dhcpv4_put(&fr_msg, &cursor, DHCPV4_OPT_MESSAGE, sizeof(msg), &msg);
if (a->accept_fr_nonce) {
- auth_o = (struct dhcpv4_auth_forcerenew *)cursor;
- dhcpv4_put(&fr_msg, &cursor, DHCPV4_OPT_AUTHENTICATION, sizeof(auth), &auth);
- dhcpv4_put(&fr_msg, &cursor, DHCPV4_OPT_END, 0, NULL);
-
+ uint8_t secretbytes[64] = { 0 };
md5_ctx_t md5;
- uint8_t secretbytes[64];
- memset(secretbytes, 0, sizeof(secretbytes));
- memcpy(secretbytes, a->key, sizeof(a->key));
+ fr_auth_body.replay[0] = htonl(time(NULL));
+ fr_auth_body.replay[1] = htonl(++serial);
+ iov[IOV_FR_AUTH].iov_len = sizeof(fr_auth);
+ iov[IOV_FR_AUTH_BODY].iov_len = sizeof(fr_auth_body);
+ dhcpv4_add_padding(iov, ARRAY_SIZE(iov));
+
+ memcpy(secretbytes, a->key, sizeof(a->key));
for (size_t i = 0; i < sizeof(secretbytes); ++i)
secretbytes[i] ^= 0x36;
md5_begin(&md5);
md5_hash(secretbytes, sizeof(secretbytes), &md5);
- md5_hash(&fr_msg, sizeof(fr_msg), &md5);
- md5_end(auth_o->key, &md5);
+ for (size_t i = 0; i < ARRAY_SIZE(iov); i++)
+ md5_hash(iov[i].iov_base, iov[i].iov_len, &md5);
+ md5_end(fr_auth_body.key, &md5);
for (size_t i = 0; i < sizeof(secretbytes); ++i) {
secretbytes[i] ^= 0x36;
md5_begin(&md5);
md5_hash(secretbytes, sizeof(secretbytes), &md5);
- md5_hash(auth_o->key, sizeof(auth_o->key), &md5);
- md5_end(auth_o->key, &md5);
+ md5_hash(fr_auth_body.key, sizeof(fr_auth_body.key), &md5);
+ md5_end(fr_auth_body.key, &md5);
} else {
- dhcpv4_put(&fr_msg, &cursor, DHCPV4_OPT_SERVERID, 4,
- &a->fr_ip->addr.addr.in.s_addr);
- dhcpv4_put(&fr_msg, &cursor, DHCPV4_OPT_END, 0, NULL);
+ iov[IOV_FR_SERVERID].iov_len = sizeof(fr_serverid);
+ dhcpv4_add_padding(iov, ARRAY_SIZE(iov));
}
- if (sendto(iface->dhcpv4_event.uloop.fd, &fr_msg, PACKET_SIZE(&fr_msg, cursor),
- MSG_DONTWAIT, (struct sockaddr*)&dest, sizeof(dest)) < 0)
- error("Failed to send %s to %s - %s: %m", dhcpv4_msg_to_string(msg),
+ if (dhcpv4_send_reply(iov, ARRAY_SIZE(iov), (struct sockaddr *)&dest, sizeof(dest),
+ &a->iface->dhcpv4_event.uloop.fd) < 0)
+ error("Failed to send %s to %s - %s: %m", dhcpv4_msg_to_string(fr_msg.data),
odhcpd_print_mac(a->hwaddr, sizeof(a->hwaddr)), inet_ntoa(dest.sin_addr));
else
- debug("Sent %s to %s - %s", dhcpv4_msg_to_string(msg),
+ debug("Sent %s to %s - %s", dhcpv4_msg_to_string(fr_msg.data),
odhcpd_print_mac(a->hwaddr, sizeof(a->hwaddr)), inet_ntoa(dest.sin_addr));
}
return a;
}
-static ssize_t dhcpv4_send_reply(struct iovec *iov, size_t iov_len,
- struct sockaddr *dest, socklen_t dest_len,
- void *opaque)
-{
- int *sock = opaque;
- struct msghdr msg = {
- .msg_name = dest,
- .msg_namelen = dest_len,
- .msg_iov = iov,
- .msg_iovlen = iov_len,
- };
-
- return sendmsg(*sock, &msg, MSG_DONTWAIT);
-}
-
static void dhcpv4_set_dest_addr(const struct interface *iface,
uint8_t reply_msg,
const struct dhcpv4_message *req,
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