On a QSFPTEK QT-SFP+-T (RTL8261C) 10GBase-T module, the diag type field
(92) comes back as 0x00, but there's actually some statistics available
like temperature. Other metrics may be hard-coded values.
Add a basic struct that allows matching on vendor and/or model, using a
bitfield to allow multiple quirks for a given SFP module. Only
SFP_QUIRK_DDM is implemented.
For modules matching SFP_QUIRK_DDM, attempt an I2C read of the MSB of
module voltage during probe if DDM is "unsupported" - if it's not 0xff,
override the reported options so we can pull the diagnostic data.
To allow simpler comparisons, convert the ASCII fields (vendor,
model, serial) from space-padded to standard NULL-terminated strings.
strcmp() is moved from httpd.c to rtlplayground.c alongside other string
functions and shared between them.
The __reentrant keyword is used for the new functions to avoid using up
additional OSEG space. This allocates the variables on the stack, which
is OK for this particular code path.
The JSON assembly in send_status() is slightly modified to treat the
sfp_module_* data as standard NULL-terminated strings, and a repeated
subtraction was moved into a uint8_t to declutter the code.
A bare "vlan N" line never matches conf_cmds (a VLAN entry always carries
a member port or the mgmt/name keyword), so it is never stored. The
c !== "vlan N" comparison could therefore never match an entry; the
startsWith(prefix) check alone covers all stored vlan lines.
The firmware has a single management VLAN (one management_vlan variable),
so a stored config should never carry more than one "vlan N mgmt" line.
When parsing a mgmt command, drop any previously stored mgmt entry so
repeatedly changing the management VLAN no longer accumulates stale lines.
parseConf() only recognized "port N name" in conf_cmds, so "port N <speed>"
lines were treated as unknown commands and dropped on save - configured port
speeds never persisted.
Add the speed command (incl. optional half/full duplex suffix) to conf_cmds,
add a "port N" entry to conf_overwrite so re-saving a speed replaces the
previous value, and guard the per-port name entry so changing a port's speed
no longer wipes its configured name.