- dev - passt

[PATCH v2 0/8] Cleanups to auto port scanning
by David Gibson 01 Nov '25

01 Nov '25

One of the trickiest parts of implementing the improved forwarding table is integrating it properly with automatic forwarding (-t auto etc.). Here are some preliminary cleanups to the automatic port scanning that will make the job a bit easier. v2: * Rename bitmap_andc() to bitmap_and_not() (4/8) * Fixed comment formatting error (4/8) * Updated commit message based on further information from Stefano (7,8/8) * All other patches unchanged, except for trivial rebase fixes David Gibson (8): icmp: Remove vestiges of ICMP timer tcp, udp, fwd: Run all port scanning from a single timer fwd: Consolidate scans (not rebinds) in fwd.c fwd: Move port exclusion handling from procfs_scan_listen() to callers fwd: Share port scanning logic between init and timer cases fwd: Check forwarding mode in fwd_scan_ports_*() rather than caller fwd: Update all port maps before applying exclusions tcp, udp: Don't exclude ports in {tcp,udp}_port_rebind() fwd.c | 107 ++++++++++++++++++++++++++++++++++++++------------------ fwd.h | 7 ++-- icmp.h | 2 -- passt.c | 8 ++--- tcp.c | 34 +++++++++--------- tcp.h | 3 +- udp.c | 31 ++++------------ udp.h | 4 +-- util.c | 24 +++++++++++++ util.h | 2 ++ 10 files changed, 131 insertions(+), 91 deletions(-) -- 2.51.0

2 9

[PATCH 3/3] test: Re-implement pasta NDP tests using tunbridge & exeter
by David Gibson 31 Oct '25

31 Oct '25

Convert the pasta NDP tests from shell and our own DSL to Python using the exeter test protocol and tunbridge network simulation library. Signed-off-by: David Gibson <david(a)gibson.dropbear.id.au> --- test/Makefile | 2 +- test/pasta/dhcp | 5 ++++ test/pasta/ndp.py | 59 ++++++++++++++++++++++++++++++++++++++++++ test/run | 6 +++-- test/tasst/__init__.py | 4 +++ test/tasst/pasta.py | 40 ++++++++++++++++++++++++++++ 6 files changed, 113 insertions(+), 3 deletions(-) create mode 100755 test/pasta/ndp.py create mode 100644 test/tasst/pasta.py diff --git a/test/Makefile b/test/Makefile index f66c7e7e..95e3d75e 100644 --- a/test/Makefile +++ b/test/Makefile @@ -67,7 +67,7 @@ ASSETS = $(DOWNLOAD_ASSETS) $(LOCAL_ASSETS) EXETER_SH = smoke/smoke.sh build/static_checkers.sh EXETER_PYPATH = exeter/py3:tunbridge/:. -EXETER_PYTHON = smoke/smoke.py build/build.py +EXETER_PYTHON = smoke/smoke.py build/build.py pasta/ndp.py EXETER_BATS = $(EXETER_SH:%=%.bats) $(EXETER_PYTHON:%=%.bats) BATS_FILES = $(EXETER_BATS) \ podman/test/system/505-networking-pasta.bats diff --git a/test/pasta/dhcp b/test/pasta/dhcp index e1c66be6..61279fbf 100644 --- a/test/pasta/dhcp +++ b/test/pasta/dhcp @@ -18,6 +18,11 @@ test Interface name nsout IFNAME ip -j link show | jq -rM '.[] | select(.link_type == "ether").ifname' check [ -n "__IFNAME__" ] +# Bring up the interface +ns ip link set dev __IFNAME__ up +# Wait for SLAAC & DAD to complete +ns while ! ip -j -6 addr show dev __IFNAME__ | jq -e '.[].addr_info.[] | select(.protocol == "kernel_ra")'; do sleep 0.1; done + test DHCP: address ns /sbin/dhclient -4 --no-pid __IFNAME__ nsout ADDR ip -j -4 addr show|jq -rM '.[] | select(.ifname == "__IFNAME__").addr_info[0].local' diff --git a/test/pasta/ndp.py b/test/pasta/ndp.py new file mode 100755 index 00000000..8c7ce31e --- /dev/null +++ b/test/pasta/ndp.py @@ -0,0 +1,59 @@ +#! /usr/bin/env python3 +# +# SPDX-License-Identifier: GPL-2.0-or-later +# +# test/pasta/ndp.py - pasta NDP functionality +# +# Copyright Red Hat +# Author: David Gibson <david(a)gibson.dropbear.id.au> + +import contextlib +import dataclasses +from typing import Iterator + +import exeter +import tunbridge +import tasst + + +(a)dataclasses.dataclass +class UnconfiguredScenario(exeter.Scenario): + """Tests for a pasta instance without --config-net""" + + host: tunbridge.Site + guest: tunbridge.Site + ifname: str + addr6: tunbridge.ip.AddrMask6 + gw6: tunbridge.ip.Addr6 + + @exeter.scenariotest + def test_ifname(self) -> None: + ifs = tunbridge.ip.ifs(self.guest) + exeter.assert_eq(set(ifs), {'lo', self.ifname}) + + @tunbridge.ndp.NdpScenario.subscenario + def test_ndp(self) -> tunbridge.ndp.NdpScenario: + tunbridge.ip.ifup(self.guest, self.ifname) + return tunbridge.ndp.NdpScenario(client=self.guest, + ifname=self.ifname, + network=self.addr6.network, + gateway=self.gw6) + + +(a)UnconfiguredScenario.test +(a)contextlib.contextmanager +def simh_pasta_setup() -> Iterator[UnconfiguredScenario]: + with (tunbridge.sample.simple_host('host') as simh, + tunbridge.sample.isolated('guest', simh.site) as guest): + assert simh.ip6 is not None + assert simh.gw6_ll is not None + with tasst.pasta.pasta(simh.site, guest): + yield UnconfiguredScenario(host=simh.site, + guest=guest, + ifname=simh.ifname, + addr6=simh.ip6, + gw6=simh.gw6_ll) + + +if __name__ == '__main__': + exeter.main() diff --git a/test/run b/test/run index 3872a56e..4f09d767 100755 --- a/test/run +++ b/test/run @@ -43,8 +43,10 @@ KERNEL=${KERNEL:-"/boot/vmlinuz-$(uname -r)"} COMMIT="$(git log --oneline --no-decorate -1)" -# Let exeter tests written in Python find their modules +# Let exeter tests written in Python find their modules and binaries to run export PYTHONPATH=${BASEPATH}/exeter/py3:${BASEPATH}/tunbridge:${BASEPATH} +export PASTA=${PASTA:-${BASEPATH}/../pasta} + . lib/util . lib/context @@ -75,8 +77,8 @@ run() { exeter build/build.py exeter build/static_checkers.sh + exeter pasta/ndp.py setup pasta - test pasta/ndp test pasta/dhcp test pasta/tcp test pasta/udp diff --git a/test/tasst/__init__.py b/test/tasst/__init__.py index fd4fe9a8..f5386b3a 100644 --- a/test/tasst/__init__.py +++ b/test/tasst/__init__.py @@ -8,3 +8,7 @@ # # Copyright Red Hat # Author: David Gibson <david(a)gibson.dropbear.id.au> + +from . import pasta + +__all__ = ['pasta'] diff --git a/test/tasst/pasta.py b/test/tasst/pasta.py new file mode 100644 index 00000000..91f59036 --- /dev/null +++ b/test/tasst/pasta.py @@ -0,0 +1,40 @@ +#! /usr/bin/env python3 +# +# SPDX-License-Identifier: GPL-2.0-or-later +# +# TASST - Test A Simple Socket Transport +# +# test/tasst/pasta.py - Helpers for seeting up pasta instances +# +# Copyright Red Hat +# Author: David Gibson <david(a)gibson.dropbear.id.au> + +import contextlib +import os +from typing import Iterator + +import tunbridge + + +(a)contextlib.contextmanager +def pasta(host: tunbridge.Site, guest: tunbridge.Site, *opts: str) \ + -> Iterator[tunbridge.site.SiteProcess]: + if tunbridge.unshare.parent(guest) is not host: + raise ValueError("pasta guest must be a namespace under host site") + + # This implies guest is a namespace site + assert isinstance(guest, tunbridge.unshare.NsenterSite) + + exe = os.environ['PASTA'] + + with host.tempdir() as piddir: + pidfile = os.path.join(piddir, 'pasta.pid') + cmd = [exe, '-f', '-P', pidfile] + list(opts) + [f'{guest.pid}'] + with host.bg(*cmd, stop=True) as pasta: + # Wait for the PID file to be written + pidstr = None + while not pidstr: + pidstr = host.readfile(pidfile, check=False) + pid = int(pidstr) + print(f'pasta started, host: {host}, guest: {guest}, pid: {pid}') + yield pasta -- 2.51.0

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[PATCH v5 0/7] Refactor epoll handling in preparation for multithreading
by Laurent Vivier 30 Oct '25

30 Oct '25

This series refactors how epoll file descriptors are managed throughout the codebase in preparation for introducing multithreading support. Currently, passt uses a single global epollfd accessed through the context structure. With multithreading, each thread will need its own epollfd managing its subset of flows. The key changes are: 1. Centralize epoll management by extracting helper functions into a new epoll_ctl.c/h module and moving union epoll_ref from passt.h to its more logical location in epoll_ctl.h. 2. Simplify epoll_del() to take the epollfd directly rather than extracting it from the context structure, reducing coupling between epoll operations and the global context. 3. Move epoll registration out of sock_l4_sa() into protocol-specific code, giving callers explicit control over which epoll instance manages each socket. 4. Replace the boolean in_epoll flag in TCP connections with an epollid (epoll identifier) field in flow_common. This serves dual purposes: tracking registration status (EPOLLFD_ID_INVALID = not registered) and identifying which epoll instance manages the flow. An epoll ID to epoll fd mapping allows retrieving the actual epoll file descriptor. The epollid field is 8 bits, limiting values to 0-254 (255 = EPOLLFD_ID_INVALID). 5. Apply this pattern consistently across all protocol handlers (TCP, ICMP, UDP), storing the managing epoll ID in each flow's common structure. 6. Extract the event loop processing logic into a separate passt_worker() function, preparing the structure for future threading where this will become a worker thread callback. These changes make epoll instance ownership explicit in the flow tracking system, enabling flows to be managed by different epoll instances, a prerequisite for per-thread epollfd design in upcoming multithreading work. Changes since v1: - New patch: "epoll_ctl: Extract epoll operations" - centralizes epoll helpers into a dedicated module and relocates union epoll_ref from passt.h to epoll_ctl.h - Changed epollfd type in flow_common from int to 8-bit bitfield to avoid exceeding cacheline size threshold - Added flow_epollfd_valid() helper to check epoll registration status - Added flow_set_epollfd() helper to set the epoll instance for a flow Changes since v2: - Renamed field in flow_common from epollfd to threadnb (thread number) to better reflect that flows are now associated with threads rather than directly with epoll file descriptors - Introduced thread-to-epollfd mapping via threadnb_to_epollfd[] array in flow.c, providing an indirection layer between threads and their epoll instances - Renamed/refactored helper functions: - flow_set_epollfd() -> flow_epollfd_set() - now takes thread number and epollfd parameters - Added flow_epollfd_get() - retrieves the epoll fd for a flow's thread - flow_epollfd_valid() - now checks threadnb instead of epollfd - Updated constants: replaced EPOLLFD_* with FLOW_THREADNB_* equivalents (e.g., EPOLLFD_INVALID -> FLOW_THREADNB_INVALID) - Applied thread-based pattern consistently across TCP, ICMP, and UDP Changes since v3: - Change warn() by err() in epoll_add() - Renamed flow_epollfd_valid() to flow_in_epoll(), flow_epollfd_get() to flow_epollfd(). - Added flow_thread_register() to register an epollfd to a thread number, and called it from main() to register c->epollfd for thread 0 (main loop) - Replaced flow_epollfd_set() by flow_thread_set() to set the thread number of a flow. - Added new patch: "passt: Move main event loop processing into passt_worker()" Changes since v4: - Renamed field in flow_common from threadnb to epollid (epoll identifier) to better reflect the abstraction - flows are associated with an epoll instance identifier rather than specifically a thread number - Renamed mapping array from threadnb_to_epollfd[] to epoll_id_to_fd[] - Renamed/refactored helper functions: - flow_thread_set() -> flow_epollid_set() - sets the epoll ID - flow_thread_register() -> flow_epollid_register() - registers the epollfd for a given epoll ID - Added flow_epollid_clear() - explicitly clears the epoll ID - Updated constants: replaced FLOW_THREADNB_* with EPOLLFD_ID_* equivalents (e.g., FLOW_THREADNB_INVALID -> EPOLLFD_ID_INVALID, FLOW_THREADNB_MAX -> EPOLLFD_ID_MAX) - Added EPOLLFD_ID_DEFAULT constant for the default (main loop) epoll instance - Clarified that EPOLLFD_ID_BITS limits the number of epoll instances, not threads (though initially there will be one epoll instance per thread) Laurent Vivier (7): util: Simplify epoll_del() interface to take epollfd directly epoll_ctl: Extract epoll operations util: Move epoll registration out of sock_l4_sa() tcp, flow: Replace per-connection in_epoll flag with an epollid in flow_common icmp: Use epoll instance management for ICMP flows udp: Use epoll instance management for UDP flows passt: Move main event loop processing into passt_worker() Makefile | 22 +++---- epoll_ctl.c | 45 ++++++++++++++ epoll_ctl.h | 51 ++++++++++++++++ flow.c | 71 +++++++++++++++++++--- flow.h | 15 ++++- icmp.c | 23 +++++--- passt.c | 163 ++++++++++++++++++++++++++++----------------------- passt.h | 34 ----------- pasta.c | 7 +-- pif.c | 32 +++++++--- repair.c | 18 +++--- tap.c | 15 ++--- tcp.c | 46 +++++++++------ tcp_conn.h | 8 +-- tcp_splice.c | 26 ++++---- udp.c | 2 +- udp_flow.c | 23 ++++++-- util.c | 28 +-------- util.h | 6 +- vhost_user.c | 14 ++--- vu_common.c | 2 +- 21 files changed, 403 insertions(+), 248 deletions(-) create mode 100644 epoll_ctl.c create mode 100644 epoll_ctl.h -- 2.51.0

3 13

[PATCH v15 0/9] Use true MAC address of LAN local remote hosts
by Jon Maloy 30 Oct '25

30 Oct '25

Bug #120 asks us to use the true MAC addresses of LAN local remote hosts, since some programs need this information. These commits introduces this for ARP, NDP, UDP, TCP and ICMP. --- v3: Updated according to feedback from Stefano and David: - Made the ARP/NDP lookup call filter out the requested address by itself, qualified by the index if the template interface - Moved the flow specific MAC address from struct flowside to struct flow_common. v4: - Updated according to feedback from David and Stefan - Added a cache table for ARP/NDP table contents v5: - Updated according to feedback from David and Stefan - Added cache table entries to FIFO/LRU queue - New criteria for when to consult ARP/NDP v6: - Simplified and merged mac cache table commits - Other changes after feedback from David. v7: - Fixes in patch #2 based on feedback from David and Stefano. v8: - Redesigned netlink and cache table part to be based on a subscription model. v8: - Small fix to patch #2 so that we cover the case when a MAC addess for a host has changed. - Added a commit where we send a gratuitous ARP/ unsolicitated NA to the guest when a new host is added to the neighbour cache table. v10: - Some fixes after feedback from David Gibson - Reordered: Moved patch #9 to position #3. - Added synchronization step between ARP/NDP table contents and the neigbour table at initialization. This reduces the number of "false" ARP/NDP replies drastically, but not completly. - (Next step could be to scan over the flow table and update affeced entries when we receive a MAC address update.) v11: - Corrected the gratuitous ARP implementation to use the "ARP Announcement" model instead of the "Gratuitous ARP reply" model. v12: - Updated based on feedback from David and Stefano - Added special handling of default GW and loopback addresses. v13: - Updated based on discussion with David and Stefano - Conceptually moved to only considering guest-side visible addresss. A lot of things became simpler and clearer through this change. Thank you, David. - Introduced a 'permanent' flag in the special entries representing addessed mapping to own host and conditionally the guest gw. This flag indicates those entries cannot be altered by possible remote hosts shadowed by these addresses. Suggested by Stefano. - Reordered patch ##4 and 5, since #5 cannot work correctly for NDP unsolicited NA until #4 is in place. - Added a new commit #2 to get later access to the flag no_map_gw. It was wrong to call fwd_neigh_table_init() from inside conf(), it has to be done in main() after random_init() and tap_backend_init(). v14: - Some fixes after feedback from David Gibson, notably - Moved the call to nat_inbound() from fwd.c to netlink.c - Added RFC quotes to explain the format of ARP announce messages. v15: - More fixes, after feedback and discussions. Notably: - Added a secondary lookup in fwd_neigh_mac_get(), so that we respond with the guest GW's MAC address in case the primary lookup fails. - Removed guest_gw IP address as 'blocker' entry in the neighbor table. It is ok to let the host GW MAC address go through if the GW addresses match, and even when they don't we found it isn't needed. - Removed previous patch #2 about no_map_gw, since the change it introduced only was needed by the the functionality we just removed as described above. Jon Maloy (9): netlink: add subscription on changes in NDP/ARP table fwd: Add cache table for ARP/NDP contents arp/ndp: respond with true MAC address of LAN local remote hosts arp/ndp: send ARP announcement / unsolicited NA when neigbour entry added flow: add MAC address of LAN local remote hosts to flow udp: forward external source MAC address through tap interface tcp: forward external source MAC address through tap interface tap: change signature of function tap_push_l2h() icmp: let icmp use mac address from flowside structure arp.c | 59 +++++++++++++- arp.h | 2 + epoll_type.h | 2 + flow.c | 2 + flow.h | 2 + fwd.c | 212 +++++++++++++++++++++++++++++++++++++++++++++++++ fwd.h | 7 ++ icmp.c | 8 +- inany.c | 1 + ndp.c | 16 +++- ndp.h | 1 + netlink.c | 208 +++++++++++++++++++++++++++++++++++++++++++++++- netlink.h | 4 + passt.c | 17 ++-- passt.h | 3 +- pasta.c | 2 +- tap.c | 24 +++--- tap.h | 7 +- tcp.c | 20 ++++- tcp.h | 2 +- tcp_buf.c | 37 ++++----- tcp_internal.h | 4 +- tcp_vu.c | 5 +- udp.c | 57 ++++++++----- udp.h | 2 +- util.h | 2 + 26 files changed, 623 insertions(+), 83 deletions(-) -- 2.50.1

3 11

[PATCH v6 0/4] Retry SYNs for inbound connections
by Yumei Huang 30 Oct '25

30 Oct '25

When a client connects, SYN would be sent to guest only once. If the guest is not connected or ready at that time, the connection will be reset in 10s. These patches introduce the SYN retry mechanism using the similar backoff timeout as linux kernel. Also update the data retransmission timeout using the backoff timeout. Yumei Huang (4): tcp: Rename "retrans" to "retries" util: Introduce read_file() and read_file_integer() function tcp: Resend SYN for inbound connections tcp: Update data retransmission timeout tcp.c | 76 +++++++++++++++++++++++++++++++++++------------- tcp.h | 5 ++++ tcp_conn.h | 12 ++++---- util.c | 84 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ util.h | 8 ++++++ 5 files changed, 159 insertions(+), 26 deletions(-) -- 2.47.0

3 43

[PATCH v3 0/4] Retry SYNs for inbound connections
by Yumei Huang 29 Oct '25

29 Oct '25

When a client connects, SYN would be sent to guest only once. If the guest is not connected or ready at that time, the connection will be reset in 10s. These patches introduce the SYN retry mechanism using the similar backoff timeout as linux kernel. Also update the data retransmission timeout using the backoff timeout. Yumei Huang (4): tcp: Rename "retrans" to "retries" util: Introduce read_file() and read_file_long() function tcp: Resend SYN for inbound connections tcp: Update data retransmission timeout tcp.c | 79 ++++++++++++++++++++++++++++++++++------------ tcp.h | 2 ++ tcp_conn.h | 12 +++---- util.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ util.h | 2 ++ 5 files changed, 161 insertions(+), 26 deletions(-) -- 2.47.0

3 30

[PATCH v3 3/8] tcp: Merge tcp_ns_sock_init[46]() into tcp_sock_init_one()
by David Gibson 29 Oct '25

29 Oct '25

Surprisingly little logic is shared between the path for creating a listen()ing socket in the guest namespace versus in the host namespace. Improve this, by extending tcp_sock_init_one() to take a pif parameter indicating where it should open the socket. This allows tcp_ns_sock_init[46]() to be removed entirely. We generalise tcp_sock_init() in the same way, although we don't use it yet, due to some subtle differences in how we bind for -t versus -T. Signed-off-by: David Gibson <david(a)gibson.dropbear.id.au> --- conf.c | 2 +- tcp.c | 100 +++++++++++++++++++-------------------------------------- tcp.h | 5 +-- 3 files changed, 37 insertions(+), 70 deletions(-) diff --git a/conf.c b/conf.c index 66b9e634..26f1bcc0 100644 --- a/conf.c +++ b/conf.c @@ -169,7 +169,7 @@ static void conf_ports_range_except(const struct ctx *c, char optname, fwd->delta[i] = to - first; if (optname == 't') - ret = tcp_sock_init(c, addr, ifname, i); + ret = tcp_sock_init(c, PIF_HOST, addr, ifname, i); else if (optname == 'u') ret = udp_sock_init(c, 0, addr, ifname, i); else diff --git a/tcp.c b/tcp.c index d63a16bf..5f4fc12c 100644 --- a/tcp.c +++ b/tcp.c @@ -2514,29 +2514,42 @@ void tcp_sock_handler(const struct ctx *c, union epoll_ref ref, /** * tcp_sock_init_one() - Initialise listening socket for address and port * @c: Execution context + * @pif: Interface to open the socket for (PIF_HOST or PIF_SPLICE) * @addr: Pointer to address for binding, NULL for dual stack any * @ifname: Name of interface to bind to, NULL if not configured * @port: Port, host order * * Return: fd for the new listening socket, negative error code on failure + * + * If pif == PIF_SPLICE, the caller must have already entered the guest ns. */ -static int tcp_sock_init_one(const struct ctx *c, const union inany_addr *addr, - const char *ifname, in_port_t port) +static int tcp_sock_init_one(const struct ctx *c, uint8_t pif, + const union inany_addr *addr, const char *ifname, + in_port_t port) { union tcp_listen_epoll_ref tref = { .port = port, - .pif = PIF_HOST, + .pif = pif, }; + const struct fwd_ports *fwd; int s; - s = pif_sock_l4(c, EPOLL_TYPE_TCP_LISTEN, PIF_HOST, addr, - ifname, port, tref.u32); + if (pif == PIF_HOST) + fwd = &c->tcp.fwd_in; + else + fwd = &c->tcp.fwd_out; + + s = pif_sock_l4(c, EPOLL_TYPE_TCP_LISTEN, pif, addr, ifname, + port, tref.u32); + + if (fwd->mode == FWD_AUTO) { + int (*socks)[IP_VERSIONS] = pif == PIF_SPLICE ? + tcp_sock_ns : tcp_sock_init_ext; - if (c->tcp.fwd_in.mode == FWD_AUTO) { if (!addr || inany_v4(addr)) - tcp_sock_init_ext[port][V4] = s < 0 ? -1 : s; + socks[port][V4] = s < 0 ? -1 : s; if (!addr || !inany_v4(addr)) - tcp_sock_init_ext[port][V6] = s < 0 ? -1 : s; + socks[port][V6] = s < 0 ? -1 : s; } if (s < 0) @@ -2548,14 +2561,16 @@ static int tcp_sock_init_one(const struct ctx *c, const union inany_addr *addr, /** * tcp_sock_init() - Create listening sockets for a given host ("inbound") port * @c: Execution context + * @pif: Interface to open the socket for (PIF_HOST or PIF_SPLICE) * @addr: Pointer to address for binding, NULL if not configured * @ifname: Name of interface to bind to, NULL if not configured * @port: Port, host order * * Return: 0 on (partial) success, negative error code on (complete) failure */ -int tcp_sock_init(const struct ctx *c, const union inany_addr *addr, - const char *ifname, in_port_t port) +int tcp_sock_init(const struct ctx *c, uint8_t pif, + const union inany_addr *addr, const char *ifname, + in_port_t port) { int r4 = FD_REF_MAX + 1, r6 = FD_REF_MAX + 1; @@ -2563,72 +2578,23 @@ int tcp_sock_init(const struct ctx *c, const union inany_addr *addr, if (!addr && c->ifi4 && c->ifi6) /* Attempt to get a dual stack socket */ - if (tcp_sock_init_one(c, NULL, ifname, port) >= 0) + if (tcp_sock_init_one(c, pif, NULL, ifname, port) >= 0) return 0; /* Otherwise create a socket per IP version */ if ((!addr || inany_v4(addr)) && c->ifi4) - r4 = tcp_sock_init_one(c, addr ? addr : &inany_any4, - ifname, port); + r4 = tcp_sock_init_one(c, pif, + addr ? addr : &inany_any4, ifname, port); if ((!addr || !inany_v4(addr)) && c->ifi6) - r6 = tcp_sock_init_one(c, addr ? addr : &inany_any6, - ifname, port); + r6 = tcp_sock_init_one(c, pif, + addr ? addr : &inany_any6, ifname, port); if (IN_INTERVAL(0, FD_REF_MAX, r4) || IN_INTERVAL(0, FD_REF_MAX, r6)) return 0; return r4 < 0 ? r4 : r6; } - -/** - * tcp_ns_sock_init4() - Init socket to listen for outbound IPv4 connections - * @c: Execution context - * @port: Port, host order - */ -static void tcp_ns_sock_init4(const struct ctx *c, in_port_t port) -{ - union tcp_listen_epoll_ref tref = { - .port = port, - .pif = PIF_SPLICE, - }; - int s; - - ASSERT(c->mode == MODE_PASTA); - - s = pif_sock_l4(c, EPOLL_TYPE_TCP_LISTEN, PIF_SPLICE, &inany_loopback4, - NULL, port, tref.u32); - if (s < 0) - s = -1; - - if (c->tcp.fwd_out.mode == FWD_AUTO) - tcp_sock_ns[port][V4] = s; -} - -/** - * tcp_ns_sock_init6() - Init socket to listen for outbound IPv6 connections - * @c: Execution context - * @port: Port, host order - */ -static void tcp_ns_sock_init6(const struct ctx *c, in_port_t port) -{ - union tcp_listen_epoll_ref tref = { - .port = port, - .pif = PIF_SPLICE, - }; - int s; - - ASSERT(c->mode == MODE_PASTA); - - s = pif_sock_l4(c, EPOLL_TYPE_TCP_LISTEN, PIF_SPLICE, &inany_loopback6, - NULL, port, tref.u32); - if (s < 0) - s = -1; - - if (c->tcp.fwd_out.mode == FWD_AUTO) - tcp_sock_ns[port][V6] = s; -} - /** * tcp_ns_sock_init() - Init socket to listen for spliced outbound connections * @c: Execution context @@ -2639,9 +2605,9 @@ static void tcp_ns_sock_init(const struct ctx *c, in_port_t port) ASSERT(!c->no_tcp); if (c->ifi4) - tcp_ns_sock_init4(c, port); + tcp_sock_init_one(c, PIF_SPLICE, &inany_loopback4, NULL, port); if (c->ifi6) - tcp_ns_sock_init6(c, port); + tcp_sock_init_one(c, PIF_SPLICE, &inany_loopback6, NULL, port); } /** @@ -2844,7 +2810,7 @@ static void tcp_port_rebind(struct ctx *c, bool outbound) if (outbound) tcp_ns_sock_init(c, port); else - tcp_sock_init(c, NULL, NULL, port); + tcp_sock_init(c, PIF_HOST, NULL, NULL, port); } } } diff --git a/tcp.h b/tcp.h index 234a8033..fb22bac0 100644 --- a/tcp.h +++ b/tcp.h @@ -18,8 +18,9 @@ void tcp_sock_handler(const struct ctx *c, union epoll_ref ref, int tcp_tap_handler(const struct ctx *c, uint8_t pif, sa_family_t af, const void *saddr, const void *daddr, uint32_t flow_lbl, const struct pool *p, int idx, const struct timespec *now); -int tcp_sock_init(const struct ctx *c, const union inany_addr *addr, - const char *ifname, in_port_t port); +int tcp_sock_init(const struct ctx *c, uint8_t pif, + const union inany_addr *addr, const char *ifname, + in_port_t port); int tcp_init(struct ctx *c); void tcp_timer(struct ctx *c, const struct timespec *now); void tcp_defer_handler(struct ctx *c); -- 2.51.0

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[PATCH v2] tap: Update some function comments for accuracy
by David Gibson 29 Oct '25

29 Oct '25

Several of the tap_push_*() functions have doc comments claiming they take the context pointer, but don't. Some (tap_push_uh[46]) were broken fairly recently, but others (tap_push_ip[46]h) have been broken for a long time. Regardless, fix all the doc comments. Reported-by: Stefano Brivio <sbrivio(a)redhat.com> Fixes: 82a839be9 ("tap: break out building of udp header from tap_udp4_send function") Fixes: 87e6a4644 ("tap: break out building of udp header from tap_udp6_send function") Fixes: 2dbc622f5 ("tap: Split tap_ip4_send() into UDP and ICMP variants") Fixes: 9d8dd8b6f ("tap: Split tap_ip6_send() into UDP and ICMP variants") Signed-off-by: David Gibson <david(a)gibson.dropbear.id.au> --- tap.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) v2: * Added missing "Fixes" tags from v1's commit message. diff --git a/tap.c b/tap.c index 95d309bd..f3d1f660 100644 --- a/tap.c +++ b/tap.c @@ -188,7 +188,7 @@ void *tap_push_l2h(const struct ctx *c, void *buf, uint16_t proto) /** * tap_push_ip4h() - Build IPv4 header for inbound packet, with checksum - * @c: Execution context + * @ip4h: Buffer in which to build the IPv4 header * @src: IPv4 source address * @dst: IPv4 destination address * @l4len: IPv4 payload length @@ -217,7 +217,7 @@ void *tap_push_ip4h(struct iphdr *ip4h, struct in_addr src, /** * tap_push_uh4() - Build UDPv4 header with checksum - * @c: Execution context + * @uh: Buffer in which to build the UDP header * @src: IPv4 source address * @sport: UDP source port * @dst: IPv4 destination address @@ -293,7 +293,7 @@ void tap_icmp4_send(const struct ctx *c, struct in_addr src, struct in_addr dst, /** * tap_push_ip6h() - Build IPv6 header for inbound packet - * @c: Execution context + * @ip6h: Buffer in which to build the IPv6 header * @src: IPv6 source address * @dst: IPv6 destination address * @l4len: L4 payload length @@ -319,7 +319,7 @@ void *tap_push_ip6h(struct ipv6hdr *ip6h, /** * tap_push_uh6() - Build UDPv6 header with checksum - * @c: Execution context + * @uh: Buffer in which to build the UDP header * @src: IPv6 source address * @sport: UDP source port * @dst: IPv6 destination address -- 2.51.0

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[PATCH v2 0/3] Reduce differences between inbound and outbound socket binding
by David Gibson 29 Oct '25

29 Oct '25

The fact that outbound forwarding sockets are bound to the loopback address, whereas inbound forwarding sockets are (by default) bound to the unspecified address leads to some unexpected differences between the paths setting up each of them. Happily there's an approach to tackling bug 100 which also reduces those differences, allowing more code to be shared between the two paths. Amongst other things, this will make the next steps of flexible forwarding configuration easier. Link: https://bugs.passt.top/show_bug.cgi?id=100 v2: - Some rearrangements and rewordings for clarity David Gibson (3): tcp: Merge tcp_ns_sock_init[46]() into tcp_sock_init_one() udp: Unify some more inbound/outbound parts of udp_sock_init() tcp, udp: Bind outbound listening sockets by interface instead of address conf.c | 4 +- pif.c | 6 --- tcp.c | 114 +++++++++++++++++---------------------------------------- tcp.h | 5 ++- udp.c | 60 +++++++++++++++--------------- udp.h | 5 ++- 6 files changed, 70 insertions(+), 124 deletions(-) -- 2.51.0

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[PATCH v2] Add reverse Christmas tree to CONTRIBUTING.md
by Yumei Huang 28 Oct '25

28 Oct '25

Also fix the copyright line. Suggested-by: Stefano Brivio <sbrivio(a)redhat.com> Signed-off-by: Yumei Huang <yuhuang(a)redhat.com> --- CONTRIBUTING.md | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md index 75ad2a7..64c191f 100644 --- a/CONTRIBUTING.md +++ b/CONTRIBUTING.md @@ -1,6 +1,6 @@  @@ -24,6 +24,10 @@ to prepare patches and participate in the email-based review process. * Edit the source code or documentation following the [Linux kernel coding style](https://www.kernel.org/doc/html/latest/process/coding-style.html). + When adding or editing local variable declarations, please use the reverse + Christmas tree as described + [here](https://www.kernel.org/doc/Documentation/process/maintainer-kvm-x86.r… + and [here](https://hisham.hm/2018/06/16/when-listing-repeated-things-make-pyramids/). * Stage your changes: -- 2.51.0

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