Allow sockops BPF programs to query the WFP flow_id #4763
There are no files selected for viewing
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,140 @@ | ||
| // Copyright (c) eBPF for Windows contributors | ||
| // SPDX-License-Identifier: MIT | ||
|
|
||
| // Whenever this sample program changes, bpf2c_tests will fail unless the | ||
| // expected files in tests\bpf2c_tests\expected are updated. The following | ||
| // script can be used to regenerate the expected files: | ||
| // generate_expected_bpf2c_output.ps1 | ||
| // | ||
| // Usage: | ||
| // .\scripts\generate_expected_bpf2c_output.ps1 <build_output_path> | ||
| // Example: | ||
| // .\scripts\generate_expected_bpf2c_output.ps1 .\x64\Debug\ | ||
|
|
||
| #include "bpf_helpers.h" | ||
| #include "ebpf_nethooks.h" | ||
| #include "net/ip.h" | ||
| #include "socket_tests_common.h" | ||
|
|
||
| struct | ||
| { | ||
| __uint(type, BPF_MAP_TYPE_HASH); | ||
| __type(key, connection_tuple_t); | ||
| __type(value, uint64_t); | ||
| __uint(max_entries, 10); | ||
| } flow_id_map SEC(".maps"); | ||
|
|
||
| struct | ||
| { | ||
| __uint(type, BPF_MAP_TYPE_RINGBUF); | ||
| __uint(max_entries, 256 * 1024); | ||
| } flow_id_audit_map SEC(".maps"); | ||
|
|
||
| typedef struct _flow_id_audit_entry | ||
| { | ||
| connection_tuple_t tuple; | ||
| uint64_t flow_id; | ||
| uint64_t process_id; | ||
| uint32_t operation; | ||
| bool outbound; | ||
| bool connected; | ||
| } flow_id_audit_entry_t; | ||
|
|
||
| inline int | ||
| update_flow_id_audit_map(flow_id_audit_entry_t* audit_entry) | ||
| { | ||
| return bpf_ringbuf_output(&flow_id_audit_map, audit_entry, sizeof(*audit_entry), 0); | ||
| } | ||
|
|
||
| inline int | ||
| handle_v4_flow_id(bpf_sock_ops_t* ctx, bool outbound, bool connected) | ||
| { | ||
| int result = 0; | ||
| flow_id_audit_entry_t audit_entry = {0}; | ||
|
|
||
| // Get the WFP flow ID using the new helper function. | ||
| uint64_t flow_id = bpf_sock_ops_get_flow_id(ctx); | ||
|
|
||
| audit_entry.tuple.local_ip.ipv4 = ctx->local_ip4; | ||
| audit_entry.tuple.local_port = ctx->local_port; | ||
| audit_entry.tuple.remote_ip.ipv4 = ctx->remote_ip4; | ||
| audit_entry.tuple.remote_port = ctx->remote_port; | ||
| audit_entry.tuple.protocol = ctx->protocol; | ||
| audit_entry.tuple.interface_luid = ctx->interface_luid; | ||
| audit_entry.process_id = bpf_get_current_pid_tgid(); | ||
| // Ignore the thread Id. | ||
| audit_entry.process_id >>= 32; | ||
| audit_entry.outbound = outbound; | ||
| audit_entry.connected = connected; | ||
| audit_entry.operation = ctx->op; | ||
| audit_entry.flow_id = flow_id; | ||
|
|
||
| // Store the flow ID in our map for later verification. | ||
| bpf_map_update_elem(&flow_id_map, &audit_entry.tuple, &flow_id, BPF_ANY); | ||
|
|
||
| return update_flow_id_audit_map(&audit_entry); | ||
| } | ||
|
|
||
| inline int | ||
| handle_v6_flow_id(bpf_sock_ops_t* ctx, bool outbound, bool connected) | ||
| { | ||
| int result = 0; | ||
| flow_id_audit_entry_t audit_entry = {0}; | ||
|
|
||
| // Get the WFP flow ID using the new helper function. | ||
| uint64_t flow_id = bpf_sock_ops_get_flow_id(ctx); | ||
|
|
||
| // Copy IPv6 addresses. | ||
| __builtin_memcpy(&audit_entry.tuple.local_ip.ipv6, &ctx->local_ip6, sizeof(audit_entry.tuple.local_ip.ipv6)); | ||
| __builtin_memcpy(&audit_entry.tuple.remote_ip.ipv6, &ctx->remote_ip6, sizeof(audit_entry.tuple.remote_ip.ipv6)); | ||
|
|
||
| audit_entry.tuple.local_port = ctx->local_port; | ||
| audit_entry.tuple.remote_port = ctx->remote_port; | ||
| audit_entry.tuple.protocol = ctx->protocol; | ||
| audit_entry.tuple.interface_luid = ctx->interface_luid; | ||
| audit_entry.process_id = bpf_get_current_pid_tgid(); | ||
| // Ignore the thread Id. | ||
| audit_entry.process_id >>= 32; | ||
| audit_entry.outbound = outbound; | ||
| audit_entry.connected = connected; | ||
| audit_entry.operation = ctx->op; | ||
| audit_entry.flow_id = flow_id; | ||
|
|
||
| // Store the flow ID in our map for later verification | ||
| bpf_map_update_elem(&flow_id_map, &audit_entry.tuple, &flow_id, BPF_ANY); | ||
|
|
||
| return update_flow_id_audit_map(&audit_entry); | ||
| } | ||
|
|
||
| SEC("sockops") | ||
| int | ||
| flow_id_monitor(bpf_sock_ops_t* ctx) | ||
| { | ||
| switch (ctx->op) { | ||
| case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB: | ||
| if (ctx->family == AF_INET) { | ||
| return handle_v4_flow_id(ctx, false, true); | ||
| } else if (ctx->family == AF_INET6) { | ||
| return handle_v6_flow_id(ctx, false, true); | ||
| } | ||
| break; | ||
| case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB: | ||
| if (ctx->family == AF_INET) { | ||
| return handle_v4_flow_id(ctx, true, true); | ||
| } else if (ctx->family == AF_INET6) { | ||
| return handle_v6_flow_id(ctx, true, true); | ||
| } | ||
| break; | ||
| case BPF_SOCK_OPS_CONNECTION_DELETED_CB: | ||
| if (ctx->family == AF_INET) { | ||
| return handle_v4_flow_id(ctx, false, false); | ||
| } else if (ctx->family == AF_INET6) { | ||
| return handle_v6_flow_id(ctx, false, false); | ||
| } | ||
| break; | ||
| } | ||
|
|
||
| return 0; | ||
| } | ||
|
|
||
| char _license[] SEC("license") = "MIT"; |
Oops, something went wrong.
Oops, something went wrong.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
can we be particularly paranoid and follow WFP runtime checks?
local_flow_context->context.flow_id = 0;
if (FWPS_IS_METADATA_FIELD_PRESENT(incoming_metadata_values, FWPS_METADATA_FIELD_FLOW_HANDLE))
{
local_flow_context->context.flow_id = incoming_metadata_values->flowHandle;
}