luci-base: resolve symlinks for PCI hardware

getBuiltinEthernetPorts crashed with "Unknown error"
on hardware where NICs have PCI subsystem symlinks at
different sysfs depths (e.g. onboard NIC vs PCIe card NIC).

The getBuiltinEthernetPorts x86_64 workaround block
needs realpath() to resolve PCI subsystem symlinks.

readlink() returns different strings ("../../../bus/pci" vs
"../../../../bus/pci") even though both resolve to /sys/bus/pci,
causing eth1 and eth2 to be incorrectly excluded from the result.

E.g.:

  eth0: /sys/class/net/eth0/device/subsystem -> ../../../bus/pci
  eth1: /sys/class/net/eth1/device/subsystem -> ../../../../bus/pci
  eth2: /sys/class/net/eth2/device/subsystem -> ../../../../bus/pci

1. Add realpath to the 'fs' module import statement
2. Use realpath() to normalize paths

Closes #8425
Reported-by: @MI2-2
Signed-off-by: Paul Donald <redacted>

diff --git a/modules/luci-base/root/usr/share/rpcd/ucode/luci b/modules/luci-base/root/usr/share/rpcd/ucode/luci
index c7796197455463cdef5bf094224f5a5d0ede935b..00e2b51474b20bd0963121240d55bfe76cac4dca 100644 (file)
--- a/modules/luci-base/root/usr/share/rpcd/ucode/luci
+++ b/modules/luci-base/root/usr/share/rpcd/ucode/luci
@@ -3,7 +3,7 @@
 
 'use strict';
 
-import { stdin, access, dirname, basename, open, popen, glob, lsdir, readfile, readlink, error } from 'fs';
+import { stdin, access, dirname, basename, open, popen, glob, lsdir, readfile, readlink, realpath, error } from 'fs';
 import { cursor } from 'uci';
 
 import { init_list, init_index, init_enabled, init_action, conntrack_list, process_list } from 'luci.sys';
@@ -636,7 +636,7 @@ const methods = {
                        /* Workaround for targets that do not enumerate  all netdevs in board.json */
                        if (uname().machine in [ 'x86_64' ] &&
                            match(ports[0]?.device, /^eth\d+$/)) {
-                               let bus = readlink(`/sys/class/net/${ports[0].device}/device/subsystem`);
+                               let bus = realpath(`/sys/class/net/${ports[0].device}/device/subsystem`);
 
                                for (let netdev in lsdir('/sys/class/net')) {
                                        if (!match(netdev, /^eth\d+$/))
@@ -645,7 +645,7 @@ const methods = {
                                        if (length(filter(ports, port => port.device == netdev)))
                                                continue;
 
-                                       if (readlink(`/sys/class/net/${netdev}/device/subsystem`) != bus)
+                                       if (realpath(`/sys/class/net/${netdev}/device/subsystem`) != bus)
                                                continue;
 
                                        push(ports, { role: 'unknown', device: netdev });