0 Fork 0

mirror of https://github.com/logicog/RTLPlayground.git synced 2026-10-29 17:54:14 +08:00

Files

T

DrDoof 56686185ce lacp: implement IEEE 802.3ad link aggregation

Dynamic link aggregation on top of the static LAGG, for RTL8372/8373:
receive, selection and mux state machines (coupled mux, one aggregator
per group), with "lacp show" to look inside. Each of the four trunk
groups runs its own aggregator on the candidate ports assigned with
"lag <n> lacp <ports>"; the engine starts with the first such group and
stops with the last.

LACPDUs reach the CPU through the reserved-multicast trap, so delivery
needs no L2 entry and nothing written per VLAN or per PVID. The trap
acts on the address before the VLAN lookup and before the ingress
filters, so a LACPDU also arrives on a port that admits tagged frames
only and on a port STP holds in blocking, neither of which a forwarded
one reaches. A trapped frame carries no VLAN tag,
so lacp_in() takes the offset of the PDU body from TRAP_RX_BODY(). The
action is set with trap_rma_set(), which leaves the flags sharing that
register alone, and "lacp off" puts the slow-protocols drop default
back. doc/lacp.md and doc/link_aggregation.md record what was measured,
including why the trap looked like a dead end at first.

The web UI gets a Static/LACP mode per group on the LAG page with live
status, and the startup-config validator knows the per-group syntax. A
host-side sandbox for the state machines runs in the test harness
together with the LAG hash check. It drives both forms of an incoming
LACPDU, so the body offset of a trapped one is covered as well.

The L2 table page iterated with the "next unicast" read method, so
static multicast entries such as an IGMP group were invisible. It now
iterates with "next address", skips L3 entries (their layout carries IP
addresses where a MAC is expected), and reports the lowest member of a
multicast entry's port mask, so such an entry shows up as a static
entry on that port.

A port taken out of LACP forgets its partner, so "lacp show" after
"lacp off" no longer reports one. Applying the same candidate set to a
group again, as the LAG page does on every Apply, leaves the trunk
alone instead of tearing it down for a second or two. lacp_in() checks
the frame length and ethertype before reading a LACPDU, so a runt or a
foreign frame on the slow-protocols address cannot leave stale buffer
bytes as a partner. The sandbox covers these three in T20-T22. On the
LAG page, LACP mode with no ports checked sends "lag N lacp off", and
the startup-config validator wants at least one port after "lacp".

2026-10-14 20:18:07 -05:00

4.0 KiB

Raw Blame History

Host unit-test harness

Compile and test individual firmware translation units on the build host with gcc + AddressSanitizer + UBSan — no SDCC, no flashing, no hardware. This is the fast inner loop for the logic-level bugs in ../../NOTES/08-findings.md (parser, line editor, HTTP header, DHCP): edit → make → see red/green in seconds instead of a minutes-long flash-and-reboot cycle.

Run

cd test
make            # build + run all tests (ASan/UBSan on)
make clean

Exit status is non-zero if any check fails, a sanitizer trips, or the watchdog fires — so it drops straight into CI.

How it works

sdcc_shim.h (force-included) erases SDCC 8051 keywords (__xdata, __code, __banked, …) so firmware sources compile under host gcc. It changes no logic — the code under test is byte-for-byte the firmware source.
hw_mock.c / hw_mock.h simulate the ASIC edge: a flat register file behind reg_read/reg_write and the SFR_DATA_* registers, with a table engine that performs a VLAN or L2 operation the moment TBL_CTRL is written, fetches a MIB counter on STAT_GET and drops entries on L2_TBL_FLUSH_CTRL. Nothing ever reports busy, so a polling loop runs once. The header states the VLAN and L2 entry layouts independently of the firmware, so a test can hold what rtl837x_port.c writes against what page_impl.c reads.
env_tables.c carries the globals and leaf calls those two modules link against; stub/ stands in for the two headers only a firmware build generates, so the harness needs no SDCC build first.
support.c / support.h mock the hardware edges: the 16-byte serial ring (sbuf), the command/history buffers, and the character-output sink (write_char etc.). Buffers are sized exactly as on target, so ASan redzones catch the same off-by-one overflows the 8051 hits.
Builds define RTLP_HOST_TEST, which hides the firmware's libc-named prototypes (memset/strlen/…) in rtl837x_common.h so they don't clash with glibc. Argument order matches libc, so on-host callers transparently use the C library. This guard is compiled out of normal firmware builds — zero on-target effect.
A SIGALRM watchdog (watchdog_arm) turns an infinite-loop bug into a fast test failure instead of a hung runner.

Current coverage

Test binary	TU under test	Findings exercised
`test_cmd_editor`	`cmd_editor.c`	C4 — full-line hang + `cmd_buffer` 1-byte overflow; basic entry & backspace regressions
`test_port_tables`	`rtl837x_port.c`	VLAN entry layout and round trip, PVID register sharing, static multicast and management entries, per-port flush, trunk membership and hash seed
`test_page_json`	`httpd/page_impl.c` + `rtl837x_port.c`	`/vlan.json`, `/vlanlist`, `/l2.json` (walk, wrap marker, paging inside `outbuf`), 64-bit counters in `/status.json` and `/counters.json`
`test_httpd_tx`	`httpd/httpd.c` + `uip/uip.c`	a GET of a static file against a client that moves its receive window: ACK accounting, continuation chunks out of flash, retransmission
`lacp/`	`rtl837x_lacp.c`	state machines against a simulated 802.3ad partner: convergence, mis-cabling, expiry, re-election, two groups, LACPDU containment entries
`port_hash/`	`port_lag_members_set()`	a LAG seeds its own hash register

Adding a test for another module

Write test_<module>.c with main() driving the module's entry points and CHECK(cond, msg) assertions.
Add any missing mocked symbols to support.c (only what the linker asks for).
Add a target in the Makefile listing test_<module>.c support.c ../<module>.c.
If the module calls a firmware libc-name (memcpy/strcpy/…), it will use the C library on host (compatible arg order); provide a fw_*-style mock only if the semantics differ in a way the test cares about.

Good next targets (pure logic, high finding density): cmd_parser.c (C6/C8), the HTTP header parser in httpd/httpd.c (S1), dhcp.c (S5).

4.0 KiB Raw Blame History

Host unit-test harness

Run

How it works

Current coverage

Adding a test for another module

4.0 KiB

Raw Blame History