461dbb2fa9
sd_dhcp_raw_option and sd_dhcp_option are essentially equivalent.
358 lines
11 KiB
C
358 lines
11 KiB
C
/* SPDX-License-Identifier: LGPL-2.1+ */
|
|
/***
|
|
Copyright © 2013 Intel Corporation. All rights reserved.
|
|
***/
|
|
|
|
#include <errno.h>
|
|
#include <stdint.h>
|
|
#include <stdio.h>
|
|
|
|
#include "alloc-util.h"
|
|
#include "dhcp-internal.h"
|
|
#include "dhcp-server-internal.h"
|
|
#include "memory-util.h"
|
|
#include "strv.h"
|
|
#include "utf8.h"
|
|
|
|
static int option_append(uint8_t options[], size_t size, size_t *offset,
|
|
uint8_t code, size_t optlen, const void *optval) {
|
|
assert(options);
|
|
assert(offset);
|
|
|
|
if (code != SD_DHCP_OPTION_END)
|
|
/* always make sure there is space for an END option */
|
|
size--;
|
|
|
|
switch (code) {
|
|
|
|
case SD_DHCP_OPTION_PAD:
|
|
case SD_DHCP_OPTION_END:
|
|
if (*offset + 1 > size)
|
|
return -ENOBUFS;
|
|
|
|
options[*offset] = code;
|
|
*offset += 1;
|
|
break;
|
|
|
|
case SD_DHCP_OPTION_USER_CLASS: {
|
|
size_t total = 0;
|
|
char **s;
|
|
|
|
STRV_FOREACH(s, (char **) optval) {
|
|
size_t len = strlen(*s);
|
|
|
|
if (len > 255)
|
|
return -ENAMETOOLONG;
|
|
|
|
total += 1 + len;
|
|
}
|
|
|
|
if (*offset + 2 + total > size)
|
|
return -ENOBUFS;
|
|
|
|
options[*offset] = code;
|
|
options[*offset + 1] = total;
|
|
*offset += 2;
|
|
|
|
STRV_FOREACH(s, (char **) optval) {
|
|
size_t len = strlen(*s);
|
|
|
|
options[*offset] = len;
|
|
|
|
memcpy(&options[*offset + 1], *s, len);
|
|
*offset += 1 + len;
|
|
}
|
|
|
|
break;
|
|
}
|
|
case SD_DHCP_OPTION_SIP_SERVER:
|
|
if (*offset + 3 + optlen > size)
|
|
return -ENOBUFS;
|
|
|
|
options[*offset] = code;
|
|
options[*offset + 1] = optlen + 1;
|
|
options[*offset + 2] = 1;
|
|
|
|
memcpy_safe(&options[*offset + 3], optval, optlen);
|
|
*offset += 3 + optlen;
|
|
|
|
break;
|
|
case SD_DHCP_OPTION_VENDOR_SPECIFIC: {
|
|
OrderedHashmap *s = (OrderedHashmap *) optval;
|
|
struct sd_dhcp_option *p;
|
|
size_t l = 0;
|
|
Iterator i;
|
|
|
|
ORDERED_HASHMAP_FOREACH(p, s, i)
|
|
l += p->length + 2;
|
|
|
|
if (*offset + l + 2 > size)
|
|
return -ENOBUFS;
|
|
|
|
options[*offset] = code;
|
|
options[*offset + 1] = l;
|
|
|
|
*offset += 2;
|
|
|
|
ORDERED_HASHMAP_FOREACH(p, s, i) {
|
|
options[*offset] = p->option;
|
|
options[*offset + 1] = p->length;
|
|
memcpy(&options[*offset + 2], p->data, p->length);
|
|
*offset += 2 + p->length;
|
|
}
|
|
|
|
break;
|
|
}
|
|
default:
|
|
if (*offset + 2 + optlen > size)
|
|
return -ENOBUFS;
|
|
|
|
options[*offset] = code;
|
|
options[*offset + 1] = optlen;
|
|
|
|
memcpy_safe(&options[*offset + 2], optval, optlen);
|
|
*offset += 2 + optlen;
|
|
|
|
break;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int dhcp_option_append(DHCPMessage *message, size_t size, size_t *offset,
|
|
uint8_t overload,
|
|
uint8_t code, size_t optlen, const void *optval) {
|
|
const bool use_file = overload & DHCP_OVERLOAD_FILE;
|
|
const bool use_sname = overload & DHCP_OVERLOAD_SNAME;
|
|
int r;
|
|
|
|
assert(message);
|
|
assert(offset);
|
|
|
|
/* If *offset is in range [0, size), we are writing to ->options,
|
|
* if *offset is in range [size, size + sizeof(message->file)) and use_file, we are writing to ->file,
|
|
* if *offset is in range [size + use_file*sizeof(message->file), size + use_file*sizeof(message->file) + sizeof(message->sname))
|
|
* and use_sname, we are writing to ->sname.
|
|
*/
|
|
|
|
if (*offset < size) {
|
|
/* still space in the options array */
|
|
r = option_append(message->options, size, offset, code, optlen, optval);
|
|
if (r >= 0)
|
|
return 0;
|
|
else if (r == -ENOBUFS && (use_file || use_sname)) {
|
|
/* did not fit, but we have more buffers to try
|
|
close the options array and move the offset to its end */
|
|
r = option_append(message->options, size, offset, SD_DHCP_OPTION_END, 0, NULL);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
*offset = size;
|
|
} else
|
|
return r;
|
|
}
|
|
|
|
if (use_file) {
|
|
size_t file_offset = *offset - size;
|
|
|
|
if (file_offset < sizeof(message->file)) {
|
|
/* still space in the 'file' array */
|
|
r = option_append(message->file, sizeof(message->file), &file_offset, code, optlen, optval);
|
|
if (r >= 0) {
|
|
*offset = size + file_offset;
|
|
return 0;
|
|
} else if (r == -ENOBUFS && use_sname) {
|
|
/* did not fit, but we have more buffers to try
|
|
close the file array and move the offset to its end */
|
|
r = option_append(message->options, size, offset, SD_DHCP_OPTION_END, 0, NULL);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
*offset = size + sizeof(message->file);
|
|
} else
|
|
return r;
|
|
}
|
|
}
|
|
|
|
if (use_sname) {
|
|
size_t sname_offset = *offset - size - use_file*sizeof(message->file);
|
|
|
|
if (sname_offset < sizeof(message->sname)) {
|
|
/* still space in the 'sname' array */
|
|
r = option_append(message->sname, sizeof(message->sname), &sname_offset, code, optlen, optval);
|
|
if (r >= 0) {
|
|
*offset = size + use_file*sizeof(message->file) + sname_offset;
|
|
return 0;
|
|
} else
|
|
/* no space, or other error, give up */
|
|
return r;
|
|
}
|
|
}
|
|
|
|
return -ENOBUFS;
|
|
}
|
|
|
|
static int parse_options(const uint8_t options[], size_t buflen, uint8_t *overload,
|
|
uint8_t *message_type, char **error_message, dhcp_option_callback_t cb,
|
|
void *userdata) {
|
|
uint8_t code, len;
|
|
const uint8_t *option;
|
|
size_t offset = 0;
|
|
|
|
while (offset < buflen) {
|
|
code = options[offset ++];
|
|
|
|
switch (code) {
|
|
case SD_DHCP_OPTION_PAD:
|
|
continue;
|
|
|
|
case SD_DHCP_OPTION_END:
|
|
return 0;
|
|
}
|
|
|
|
if (buflen < offset + 1)
|
|
return -ENOBUFS;
|
|
|
|
len = options[offset ++];
|
|
|
|
if (buflen < offset + len)
|
|
return -EINVAL;
|
|
|
|
option = &options[offset];
|
|
|
|
switch (code) {
|
|
case SD_DHCP_OPTION_MESSAGE_TYPE:
|
|
if (len != 1)
|
|
return -EINVAL;
|
|
|
|
if (message_type)
|
|
*message_type = *option;
|
|
|
|
break;
|
|
|
|
case SD_DHCP_OPTION_ERROR_MESSAGE:
|
|
if (len == 0)
|
|
return -EINVAL;
|
|
|
|
if (error_message) {
|
|
_cleanup_free_ char *string = NULL;
|
|
|
|
/* Accept a trailing NUL byte */
|
|
if (memchr(option, 0, len - 1))
|
|
return -EINVAL;
|
|
|
|
string = memdup_suffix0((const char *) option, len);
|
|
if (!string)
|
|
return -ENOMEM;
|
|
|
|
if (!ascii_is_valid(string))
|
|
return -EINVAL;
|
|
|
|
free_and_replace(*error_message, string);
|
|
}
|
|
|
|
break;
|
|
case SD_DHCP_OPTION_OVERLOAD:
|
|
if (len != 1)
|
|
return -EINVAL;
|
|
|
|
if (overload)
|
|
*overload = *option;
|
|
|
|
break;
|
|
|
|
default:
|
|
if (cb)
|
|
cb(code, len, option, userdata);
|
|
|
|
break;
|
|
}
|
|
|
|
offset += len;
|
|
}
|
|
|
|
if (offset < buflen)
|
|
return -EINVAL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
int dhcp_option_parse(DHCPMessage *message, size_t len, dhcp_option_callback_t cb, void *userdata, char **_error_message) {
|
|
_cleanup_free_ char *error_message = NULL;
|
|
uint8_t overload = 0;
|
|
uint8_t message_type = 0;
|
|
int r;
|
|
|
|
if (!message)
|
|
return -EINVAL;
|
|
|
|
if (len < sizeof(DHCPMessage))
|
|
return -EINVAL;
|
|
|
|
len -= sizeof(DHCPMessage);
|
|
|
|
r = parse_options(message->options, len, &overload, &message_type, &error_message, cb, userdata);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
if (overload & DHCP_OVERLOAD_FILE) {
|
|
r = parse_options(message->file, sizeof(message->file), NULL, &message_type, &error_message, cb, userdata);
|
|
if (r < 0)
|
|
return r;
|
|
}
|
|
|
|
if (overload & DHCP_OVERLOAD_SNAME) {
|
|
r = parse_options(message->sname, sizeof(message->sname), NULL, &message_type, &error_message, cb, userdata);
|
|
if (r < 0)
|
|
return r;
|
|
}
|
|
|
|
if (message_type == 0)
|
|
return -ENOMSG;
|
|
|
|
if (_error_message && IN_SET(message_type, DHCP_NAK, DHCP_DECLINE))
|
|
*_error_message = TAKE_PTR(error_message);
|
|
|
|
return message_type;
|
|
}
|
|
|
|
static sd_dhcp_option* dhcp_option_free(sd_dhcp_option *i) {
|
|
if (!i)
|
|
return NULL;
|
|
|
|
free(i->data);
|
|
return mfree(i);
|
|
}
|
|
|
|
int sd_dhcp_option_new(uint8_t option, const void *data, size_t length, sd_dhcp_option **ret) {
|
|
assert_return(ret, -EINVAL);
|
|
assert_return(length == 0 || data, -EINVAL);
|
|
|
|
_cleanup_free_ void *q = memdup(data, length);
|
|
if (!q)
|
|
return -ENOMEM;
|
|
|
|
sd_dhcp_option *p = new(sd_dhcp_option, 1);
|
|
if (!p)
|
|
return -ENOMEM;
|
|
|
|
*p = (sd_dhcp_option) {
|
|
.n_ref = 1,
|
|
.option = option,
|
|
.length = length,
|
|
.data = TAKE_PTR(q),
|
|
};
|
|
|
|
*ret = TAKE_PTR(p);
|
|
return 0;
|
|
}
|
|
|
|
DEFINE_TRIVIAL_REF_UNREF_FUNC(sd_dhcp_option, sd_dhcp_option, dhcp_option_free);
|
|
DEFINE_HASH_OPS_WITH_VALUE_DESTRUCTOR(
|
|
dhcp_option_hash_ops,
|
|
void,
|
|
trivial_hash_func,
|
|
trivial_compare_func,
|
|
sd_dhcp_option,
|
|
sd_dhcp_option_unref);
|