diff options
Diffstat (limited to 'src/libsystemd-network/dhcp-option.c')
| -rw-r--r-- | src/libsystemd-network/dhcp-option.c | 113 |
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; } |