Merge branch 'add-selftests-helper-to-get-n-unique-ports'

Dimitri Daskalakis says:

====================
Add selftests helper to get N unique ports

The rss_ctx.py tests would occasionally flake. I found that the successive
calls to rand_port would occasionally return duplicate ports, breaking the
tests invariants.

Add a new helper that guarantees generated ports are unique.
====================

Link: https://patch.msgid.link/20260224224659.1507082-1-dimitri.daskalakis1@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

5 files changed, 35 insertions, 16 deletions

diff --git a/tools/testing/selftests/drivers/net/hw/lib/py/__init__.py b/tools/testing/selftests/drivers/net/hw/lib/py/__init__.py
index d5d247eca6b7..1971577d47e9 100644
--- a/tools/testing/selftests/drivers/net/hw/lib/py/__init__.py
+++ b/tools/testing/selftests/drivers/net/hw/lib/py/__init__.py
@@ -22,7 +22,8 @@ try:
         NlError, RtnlFamily, DevlinkFamily, PSPFamily
     from net.lib.py import CmdExitFailure
     from net.lib.py import bkg, cmd, bpftool, bpftrace, defer, ethtool, \
-        fd_read_timeout, ip, rand_port, wait_port_listen, wait_file, tool
+        fd_read_timeout, ip, rand_port, rand_ports, wait_port_listen, \
+        wait_file, tool
     from net.lib.py import KsftSkipEx, KsftFailEx, KsftXfailEx
     from net.lib.py import ksft_disruptive, ksft_exit, ksft_pr, ksft_run, \
         ksft_setup, ksft_variants, KsftNamedVariant
@@ -36,7 +37,7 @@ try:
                "NlError", "RtnlFamily", "DevlinkFamily", "PSPFamily",
                "CmdExitFailure",
                "bkg", "cmd", "bpftool", "bpftrace", "defer", "ethtool",
-               "fd_read_timeout", "ip", "rand_port",
+               "fd_read_timeout", "ip", "rand_port", "rand_ports",
                "wait_port_listen", "wait_file", "tool",
                "KsftSkipEx", "KsftFailEx", "KsftXfailEx",
                "ksft_disruptive", "ksft_exit", "ksft_pr", "ksft_run",
diff --git a/tools/testing/selftests/drivers/net/hw/rss_ctx.py b/tools/testing/selftests/drivers/net/hw/rss_ctx.py
index ed7e405682f0..cbeb3a38fdfe 100755
--- a/tools/testing/selftests/drivers/net/hw/rss_ctx.py
+++ b/tools/testing/selftests/drivers/net/hw/rss_ctx.py
@@ -9,7 +9,7 @@ from lib.py import ksft_eq, ksft_ne, ksft_ge, ksft_in, ksft_lt, ksft_true, ksft_
 from lib.py import NetDrvEpEnv
 from lib.py import EthtoolFamily, NetdevFamily
 from lib.py import KsftSkipEx, KsftFailEx
-from lib.py import rand_port
+from lib.py import rand_port, rand_ports
 from lib.py import ethtool, ip, defer, GenerateTraffic, CmdExitFailure
 
 
@@ -452,7 +452,7 @@ def test_rss_context(cfg, ctx_cnt=1, create_with_cfg=None):
         except:
             raise KsftSkipEx("Not enough queues for the test")
 
-    ports = []
+    ports = rand_ports(ctx_cnt)
 
     # Use queues 0 and 1 for normal traffic
     ethtool(f"-X {cfg.ifname} equal 2")
@@ -486,7 +486,6 @@ def test_rss_context(cfg, ctx_cnt=1, create_with_cfg=None):
         ksft_eq(min(data['rss-indirection-table']), 2 + i * 2, "Unexpected context cfg: " + str(data))
         ksft_eq(max(data['rss-indirection-table']), 2 + i * 2 + 1, "Unexpected context cfg: " + str(data))
 
-        ports.append(rand_port())
         flow = f"flow-type tcp{cfg.addr_ipver} dst-ip {cfg.addr} dst-port {ports[i]} context {ctx_id}"
         ntuple = ethtool_create(cfg, "-N", flow)
         defer(ethtool, f"-N {cfg.ifname} delete {ntuple}")
@@ -542,7 +541,7 @@ def test_rss_context_out_of_order(cfg, ctx_cnt=4):
 
     ntuple = []
     ctx = []
-    ports = []
+    ports = rand_ports(ctx_cnt)
 
     def remove_ctx(idx):
         ntuple[idx].exec()
@@ -574,7 +573,6 @@ def test_rss_context_out_of_order(cfg, ctx_cnt=4):
         ctx_id = ethtool_create(cfg, "-X", f"context new start {2 + i * 2} equal 2")
         ctx.append(defer(ethtool, f"-X {cfg.ifname} context {ctx_id} delete"))
 
-        ports.append(rand_port())
         flow = f"flow-type tcp{cfg.addr_ipver} dst-ip {cfg.addr} dst-port {ports[i]} context {ctx_id}"
         ntuple_id = ethtool_create(cfg, "-N", flow)
         ntuple.append(defer(ethtool, f"-N {cfg.ifname} delete {ntuple_id}"))
@@ -788,9 +786,10 @@ def test_rss_default_context_rule(cfg):
     ethtool(f"-N {cfg.ifname} {flow_generic}")
     defer(ethtool, f"-N {cfg.ifname} delete 1")
 
+    ports = rand_ports(2)
     # Specific high-priority rule for a random port that should stay on context 0.
     # Assign loc 0 so it is evaluated before the generic rule.
-    port_main = rand_port()
+    port_main = ports[0]
     flow_main = f"flow-type tcp{cfg.addr_ipver} dst-ip {cfg.addr} dst-port {port_main} context 0 loc 0"
     ethtool(f"-N {cfg.ifname} {flow_main}")
     defer(ethtool, f"-N {cfg.ifname} delete 0")
@@ -803,7 +802,7 @@ def test_rss_default_context_rule(cfg):
                           'empty' : (2, 3) })
 
     # And that traffic for any other port is steered to the new context
-    port_other = rand_port()
+    port_other = ports[1]
     _send_traffic_check(cfg, port_other, f"context {ctx_id}",
                         { 'target': (2, 3),
                           'noise' : (0, 1) })
diff --git a/tools/testing/selftests/drivers/net/lib/py/__init__.py b/tools/testing/selftests/drivers/net/lib/py/__init__.py
index 8b75faa9af6d..5872d114f142 100644
--- a/tools/testing/selftests/drivers/net/lib/py/__init__.py
+++ b/tools/testing/selftests/drivers/net/lib/py/__init__.py
@@ -22,7 +22,7 @@ try:
         NlError, RtnlFamily, DevlinkFamily, PSPFamily
     from net.lib.py import CmdExitFailure
     from net.lib.py import bkg, cmd, bpftool, bpftrace, defer, ethtool, \
-        fd_read_timeout, ip, rand_port, wait_port_listen, wait_file
+        fd_read_timeout, ip, rand_port, rand_ports, wait_port_listen, wait_file
     from net.lib.py import KsftSkipEx, KsftFailEx, KsftXfailEx
     from net.lib.py import ksft_disruptive, ksft_exit, ksft_pr, ksft_run, \
         ksft_setup, ksft_variants, KsftNamedVariant
@@ -34,7 +34,7 @@ try:
                "NlError", "RtnlFamily", "DevlinkFamily", "PSPFamily",
                "CmdExitFailure",
                "bkg", "cmd", "bpftool", "bpftrace", "defer", "ethtool",
-               "fd_read_timeout", "ip", "rand_port",
+               "fd_read_timeout", "ip", "rand_port", "rand_ports",
                "wait_port_listen", "wait_file",
                "KsftSkipEx", "KsftFailEx", "KsftXfailEx",
                "ksft_disruptive", "ksft_exit", "ksft_pr", "ksft_run",
diff --git a/tools/testing/selftests/net/lib/py/__init__.py b/tools/testing/selftests/net/lib/py/__init__.py
index f528b67639de..a584e7f806a4 100644
--- a/tools/testing/selftests/net/lib/py/__init__.py
+++ b/tools/testing/selftests/net/lib/py/__init__.py
@@ -13,7 +13,8 @@ from .ksft import KsftFailEx, KsftSkipEx, KsftXfailEx, ksft_pr, ksft_eq, \
 from .netns import NetNS, NetNSEnter
 from .nsim import NetdevSim, NetdevSimDev
 from .utils import CmdExitFailure, fd_read_timeout, cmd, bkg, defer, \
-    bpftool, ip, ethtool, bpftrace, rand_port, wait_port_listen, wait_file, tool
+    bpftool, ip, ethtool, bpftrace, rand_port, rand_ports, wait_port_listen, \
+    wait_file, tool
 from .ynl import NlError, YnlFamily, EthtoolFamily, NetdevFamily, RtnlFamily, RtnlAddrFamily
 from .ynl import NetshaperFamily, DevlinkFamily, PSPFamily
 
@@ -25,7 +26,7 @@ __all__ = ["KSRC",
            "ksft_run", "ksft_exit", "ksft_variants", "KsftNamedVariant",
            "NetNS", "NetNSEnter",
            "CmdExitFailure", "fd_read_timeout", "cmd", "bkg", "defer",
-           "bpftool", "ip", "ethtool", "bpftrace", "rand_port",
+           "bpftool", "ip", "ethtool", "bpftrace", "rand_port", "rand_ports",
            "wait_port_listen", "wait_file", "tool",
            "NetdevSim", "NetdevSimDev",
            "NetshaperFamily", "DevlinkFamily", "PSPFamily", "NlError",
diff --git a/tools/testing/selftests/net/lib/py/utils.py b/tools/testing/selftests/net/lib/py/utils.py
index 09535346c13d..5ffd9fb2a8ce 100644
--- a/tools/testing/selftests/net/lib/py/utils.py
+++ b/tools/testing/selftests/net/lib/py/utils.py
@@ -281,9 +281,27 @@ def rand_port(stype=socket.SOCK_STREAM):
     """
     Get a random unprivileged port.
     """
-    with socket.socket(socket.AF_INET6, stype) as s:
-        s.bind(("", 0))
-        return s.getsockname()[1]
+    return rand_ports(1, stype)[0]
+
+
+def rand_ports(count, stype=socket.SOCK_STREAM):
+    """
+    Get a unique set of random unprivileged ports.
+    """
+    sockets = []
+    ports = []
+
+    try:
+        for _ in range(count):
+            s = socket.socket(socket.AF_INET6, stype)
+            sockets.append(s)
+            s.bind(("", 0))
+            ports.append(s.getsockname()[1])
+    finally:
+        for s in sockets:
+            s.close()
+
+    return ports
 
 
 def wait_port_listen(port, proto="tcp", ns=None, host=None, sleep=0.005, deadline=5):