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Diffstat (limited to 'src/libsystemd-dhcp/dhcp-option.c')
-rw-r--r--src/libsystemd-dhcp/dhcp-option.c184
1 files changed, 184 insertions, 0 deletions
diff --git a/src/libsystemd-dhcp/dhcp-option.c b/src/libsystemd-dhcp/dhcp-option.c
new file mode 100644
index 0000000000..4d45b3b3a4
--- /dev/null
+++ b/src/libsystemd-dhcp/dhcp-option.c
@@ -0,0 +1,184 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+ This file is part of systemd.
+
+ Copyright (C) 2013 Intel Corporation. All rights reserved.
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version.
+
+ systemd is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <stdint.h>
+#include <string.h>
+#include <errno.h>
+#include <stdio.h>
+
+#include "dhcp-internal.h"
+
+int dhcp_option_append(uint8_t **buf, size_t *buflen, uint8_t code,
+ size_t optlen, const void *optval)
+{
+ if (!buf || !buflen)
+ return -EINVAL;
+
+ switch (code) {
+
+ case DHCP_OPTION_PAD:
+ case DHCP_OPTION_END:
+ if (*buflen < 1)
+ return -ENOBUFS;
+
+ (*buf)[0] = code;
+ *buf += 1;
+ *buflen -= 1;
+ break;
+
+ default:
+ if (*buflen < optlen + 2)
+ return -ENOBUFS;
+
+ if (!optval)
+ return -EINVAL;
+
+ (*buf)[0] = code;
+ (*buf)[1] = optlen;
+ memcpy(&(*buf)[2], optval, optlen);
+
+ *buf += optlen + 2;
+ *buflen -= (optlen + 2);
+
+ break;
+ }
+
+ return 0;
+}
+
+static int parse_options(const uint8_t *buf, size_t buflen, uint8_t *overload,
+ uint8_t *message_type, dhcp_option_cb_t cb,
+ void *user_data)
+{
+ const uint8_t *code = buf;
+ const uint8_t *len;
+
+ while (buflen > 0) {
+ switch (*code) {
+ case DHCP_OPTION_PAD:
+ buflen -= 1;
+ code++;
+ break;
+
+ case DHCP_OPTION_END:
+ return 0;
+
+ case DHCP_OPTION_MESSAGE_TYPE:
+ if (buflen < 3)
+ return -ENOBUFS;
+ buflen -= 3;
+
+ len = code + 1;
+ if (*len != 1)
+ return -EINVAL;
+
+ if (message_type)
+ *message_type = *(len + 1);
+
+ code += 3;
+
+ break;
+
+ case DHCP_OPTION_OVERLOAD:
+ if (buflen < 3)
+ return -ENOBUFS;
+ buflen -= 3;
+
+ len = code + 1;
+ if (*len != 1)
+ return -EINVAL;
+
+ if (overload)
+ *overload = *(len + 1);
+
+ code += 3;
+
+ break;
+
+ default:
+ if (buflen < 3)
+ return -ENOBUFS;
+
+ len = code + 1;
+
+ if (buflen < (size_t)*len + 2)
+ return -EINVAL;
+ buflen -= *len + 2;
+
+ if (cb)
+ cb(*code, *len, len + 1, user_data);
+
+ code += *len + 2;
+
+ break;
+ }
+ }
+
+ if (buflen)
+ return -EINVAL;
+
+ return 0;
+}
+
+int dhcp_option_parse(DHCPMessage *message, size_t len,
+ dhcp_option_cb_t cb, void *user_data)
+{
+ uint8_t overload = 0;
+ uint8_t message_type = 0;
+ uint8_t *opt = (uint8_t *)(message + 1);
+ int res;
+
+ if (!message)
+ return -EINVAL;
+
+ if (len < sizeof(DHCPMessage) + 4)
+ return -EINVAL;
+
+ len -= sizeof(DHCPMessage) + 4;
+
+ if (opt[0] != 0x63 && opt[1] != 0x82 && opt[2] != 0x53 &&
+ opt[3] != 0x63)
+ return -EINVAL;
+
+ res = parse_options(&opt[4], len, &overload, &message_type,
+ cb, user_data);
+ if (res < 0)
+ return res;
+
+ if (overload & DHCP_OVERLOAD_FILE) {
+ res = parse_options(message->file, sizeof(message->file),
+ NULL, &message_type, cb, user_data);
+ if (res < 0)
+ return res;
+ }
+
+ if (overload & DHCP_OVERLOAD_SNAME) {
+ res = parse_options(message->sname, sizeof(message->sname),
+ NULL, &message_type, cb, user_data);
+ if (res < 0)
+ return res;
+ }
+
+ if (message_type)
+ return message_type;
+
+ return -ENOMSG;
+}