diff options
Diffstat (limited to 'NetworkPkg/Ip4Dxe/Ip4Option.c')
| -rw-r--r-- | NetworkPkg/Ip4Dxe/Ip4Option.c | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/NetworkPkg/Ip4Dxe/Ip4Option.c b/NetworkPkg/Ip4Dxe/Ip4Option.c new file mode 100644 index 0000000000..f1c10014e8 --- /dev/null +++ b/NetworkPkg/Ip4Dxe/Ip4Option.c @@ -0,0 +1,204 @@ +/** @file
+ IP4 option support functions.
+
+Copyright (c) 2005 - 2018, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "Ip4Impl.h"
+
+
+/**
+ Validate the IP4 option format for both the packets we received
+ and will transmit.
+
+ @param[in] Option The first byte of the option
+ @param[in] OptionLen The length of the whole option
+ @param[in] Rcvd The option is from the packet we received if TRUE,
+ otherwise the option we wants to transmit.
+
+ @retval TRUE The option is properly formatted
+ @retval FALSE The option is mal-formated
+
+**/
+BOOLEAN
+Ip4OptionIsValid (
+ IN UINT8 *Option,
+ IN UINT32 OptionLen,
+ IN BOOLEAN Rcvd
+ )
+{
+ UINT32 Cur;
+ UINT32 Len;
+ UINT32 Point;
+
+ Cur = 0;
+
+ while (Cur < OptionLen) {
+ switch (Option[Cur]) {
+ case IP4_OPTION_NOP:
+ Cur++;
+ break;
+
+ case IP4_OPTION_EOP:
+ Cur = OptionLen;
+ break;
+
+ case IP4_OPTION_LSRR:
+ case IP4_OPTION_SSRR:
+ case IP4_OPTION_RR:
+ Len = Option[Cur + 1];
+ Point = Option[Cur + 2];
+
+ //
+ // SRR/RR options are formatted as |Type|Len|Point|Ip1|Ip2|...
+ //
+ if ((OptionLen - Cur < Len) || (Len < 3) || ((Len - 3) % 4 != 0)) {
+ return FALSE;
+ }
+
+ if ((Point > Len + 1) || (Point % 4 != 0)) {
+ return FALSE;
+ }
+
+ //
+ // The Point must point pass the last entry if the packet is received
+ // by us. It must point to 4 if the packet is to be sent by us for
+ // source route option.
+ //
+ if ((Option[Cur] != IP4_OPTION_RR) &&
+ ((Rcvd && (Point != Len + 1)) || (!Rcvd && (Point != 4)))) {
+
+ return FALSE;
+ }
+
+ Cur += Len;
+ break;
+
+ default:
+ Len = Option[Cur + 1];
+
+ if ((OptionLen - Cur < Len) || (Len < 2)) {
+ return FALSE;
+ }
+
+ Cur = Cur + Len;
+ break;
+ }
+
+ }
+
+ return TRUE;
+}
+
+
+/**
+ Copy the option from the original option to buffer. It
+ handles the details such as:
+ 1. whether copy the single IP4 option to the first/non-first
+ fragments.
+ 2. Pad the options copied over to aligned to 4 bytes.
+
+ @param[in] Option The original option to copy from
+ @param[in] OptionLen The length of the original option
+ @param[in] FirstFragment Whether it is the first fragment
+ @param[in, out] Buf The buffer to copy options to. NULL
+ @param[in, out] BufLen The length of the buffer
+
+ @retval EFI_SUCCESS The options are copied over
+ @retval EFI_BUFFER_TOO_SMALL Buf is NULL or BufLen provided is too small.
+
+**/
+EFI_STATUS
+Ip4CopyOption (
+ IN UINT8 *Option,
+ IN UINT32 OptionLen,
+ IN BOOLEAN FirstFragment,
+ IN OUT UINT8 *Buf, OPTIONAL
+ IN OUT UINT32 *BufLen
+ )
+{
+ UINT8 OptBuf[40];
+ UINT32 Cur;
+ UINT32 Next;
+ UINT8 Type;
+ UINT32 Len;
+
+ ASSERT ((BufLen != NULL) && (OptionLen <= 40));
+
+ Cur = 0;
+ Next = 0;
+
+ while (Cur < OptionLen) {
+ Type = Option[Cur];
+ Len = Option[Cur + 1];
+
+ if (Type == IP4_OPTION_NOP) {
+ //
+ // Keep the padding, in case that the sender wants to align
+ // the option, say, to 4 bytes
+ //
+ OptBuf[Next] = IP4_OPTION_NOP;
+ Next++;
+ Cur++;
+
+ } else if (Type == IP4_OPTION_EOP) {
+ //
+ // Don't append the EOP to avoid including only a EOP option
+ //
+ break;
+
+ } else {
+ //
+ // don't copy options that is only valid for the first fragment
+ //
+ if (FirstFragment || (Type & IP4_OPTION_COPY_MASK) != 0) {
+ CopyMem (OptBuf + Next, Option + Cur, Len);
+ Next += Len;
+ }
+
+ Cur += Len;
+ }
+ }
+
+ //
+ // Don't append an EOP only option.
+ //
+ if (Next == 0) {
+ *BufLen = 0;
+ return EFI_SUCCESS;
+ }
+
+ //
+ // Append an EOP if the end of option doesn't coincide with the
+ // end of the IP header, that is, isn't aligned to 4 bytes..
+ //
+ if ((Next % 4) != 0) {
+ OptBuf[Next] = IP4_OPTION_EOP;
+ Next++;
+ }
+
+ //
+ // Head length is in the unit of 4 bytes. Now, Len is the
+ // acutal option length to appear in the IP header.
+ //
+ Len = ((Next + 3) &~0x03);
+
+ //
+ // If the buffer is too small, set the BufLen then return
+ //
+ if ((Buf == NULL) || (*BufLen < Len)) {
+ *BufLen = Len;
+ return EFI_BUFFER_TOO_SMALL;
+ }
+
+ //
+ // Copy the option to the Buf, zero the buffer first to pad
+ // the options with NOP to align to 4 bytes.
+ //
+ ZeroMem (Buf, Len);
+ CopyMem (Buf, OptBuf, Next);
+ *BufLen = Len;
+ return EFI_SUCCESS;
+}
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