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Diffstat (limited to 'src/libsystemd-network/dhcp-option.c')
-rw-r--r--src/libsystemd-network/dhcp-option.c113
1 files changed, 65 insertions, 48 deletions
diff --git a/src/libsystemd-network/dhcp-option.c b/src/libsystemd-network/dhcp-option.c
index 36be7d54ed..1de7f3639c 100644
--- a/src/libsystemd-network/dhcp-option.c
+++ b/src/libsystemd-network/dhcp-option.c
@@ -19,10 +19,13 @@
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
-#include <stdint.h>
-#include <string.h>
#include <errno.h>
+#include <stdint.h>
#include <stdio.h>
+#include <string.h>
+
+#include "alloc-util.h"
+#include "utf8.h"
#include "dhcp-internal.h"
@@ -139,72 +142,84 @@ int dhcp_option_append(DHCPMessage *message, size_t size, size_t *offset,
}
static int parse_options(const uint8_t options[], size_t buflen, uint8_t *overload,
- uint8_t *message_type, dhcp_option_cb_t cb,
+ uint8_t *message_type, char **error_message, dhcp_option_cb_t cb,
void *userdata) {
uint8_t code, len;
+ const uint8_t *option;
size_t offset = 0;
while (offset < buflen) {
- switch (options[offset]) {
- case DHCP_OPTION_PAD:
- offset++;
+ code = options[offset ++];
- break;
+ switch (code) {
+ case DHCP_OPTION_PAD:
+ continue;
case DHCP_OPTION_END:
return 0;
+ }
- case DHCP_OPTION_MESSAGE_TYPE:
- if (buflen < offset + 3)
- return -ENOBUFS;
+ if (buflen < offset + 1)
+ return -ENOBUFS;
+
+ len = options[offset ++];
+
+ if (buflen < offset + len)
+ return -EINVAL;
+
+ option = &options[offset];
- len = options[++offset];
+ switch (code) {
+ case DHCP_OPTION_MESSAGE_TYPE:
if (len != 1)
return -EINVAL;
if (message_type)
- *message_type = options[++offset];
- else
- offset++;
-
- offset++;
+ *message_type = *option;
break;
- case DHCP_OPTION_OVERLOAD:
- if (buflen < offset + 3)
- return -ENOBUFS;
-
- len = options[++offset];
- if (len != 1)
+ case DHCP_OPTION_ERROR_MESSAGE:
+ if (len == 0)
return -EINVAL;
- if (overload)
- *overload = options[++offset];
- else
- offset++;
+ if (error_message) {
+ _cleanup_free_ char *string = NULL;
- offset++;
+ /* Accept a trailing NUL byte */
+ if (memchr(option, 0, len - 1))
+ return -EINVAL;
- break;
+ string = strndup((const char *) option, len);
+ if (!string)
+ return -ENOMEM;
- default:
- if (buflen < offset + 3)
- return -ENOBUFS;
+ if (!ascii_is_valid(string))
+ return -EINVAL;
- code = options[offset];
- len = options[++offset];
+ free(*error_message);
+ *error_message = string;
+ string = NULL;
+ }
- if (buflen < ++offset + len)
+ break;
+ case DHCP_OPTION_OVERLOAD:
+ if (len != 1)
return -EINVAL;
- if (cb)
- cb(code, len, &options[offset], userdata);
+ if (overload)
+ *overload = *option;
+
+ break;
- offset += len;
+ default:
+ if (cb)
+ cb(code, len, option, userdata);
break;
}
+
+ offset += len;
}
if (offset < buflen)
@@ -213,8 +228,8 @@ static int parse_options(const uint8_t options[], size_t buflen, uint8_t *overlo
return 0;
}
-int dhcp_option_parse(DHCPMessage *message, size_t len,
- dhcp_option_cb_t cb, void *userdata) {
+int dhcp_option_parse(DHCPMessage *message, size_t len, dhcp_option_cb_t cb, void *userdata, char **_error_message) {
+ _cleanup_free_ char *error_message = NULL;
uint8_t overload = 0;
uint8_t message_type = 0;
int r;
@@ -227,27 +242,29 @@ int dhcp_option_parse(DHCPMessage *message, size_t len,
len -= sizeof(DHCPMessage);
- r = parse_options(message->options, len, &overload, &message_type,
- cb, userdata);
+ 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, cb, userdata);
+ 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, cb, userdata);
+ r = parse_options(message->sname, sizeof(message->sname), NULL, &message_type, &error_message, cb, userdata);
if (r < 0)
return r;
}
- if (message_type)
- return message_type;
+ if (message_type == 0)
+ return -ENOMSG;
+
+ if (_error_message && IN_SET(message_type, DHCP_NAK, DHCP_DECLINE)) {
+ *_error_message = error_message;
+ error_message = NULL;
+ }
- return -ENOMSG;
+ return message_type;
}