July 2026 - dev

[PATCH 0/3] Fix broken build with -DNDEBUG
by David Gibson 04 Jul '26

04 Jul '26

Fix the trivial but nasty with -DNDEBUG builds recently reported by Jan Palus. While we're there, add a couple of extra build tests. These wouldn't actually catch this problem, but they're better than nothing and do catch the #include problem I also spotted. David Gibson (3): test: Extend exeter build tests to cover more recent binaries Fix build with -DNDEBUG test: Add test for builds with -DNDEBUG test/build/build.py | 25 +++++++++++++++++++++---- util.h | 3 ++- 2 files changed, 23 insertions(+), 5 deletions(-) -- 2.54.0

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[PATCH v4 00/13] Rework option parsing in preparation for destination remapping
by David Gibson 03 Jul '26

03 Jul '26

This was... a bit of a nightmare. It took way too long and went down a bunch of blind alleys. I'm not sure how much I like the final result: it's pleasingly terse in some cases, but in others it feels dangerously subtle, requiring a pretty careful understanding of the sequencing rules of C's &&, || and , operators. That said, while I was at many points ready to pack it in and hack my around the problems limiting the parsing for destination remapping, I couldn't really think of feasible way to do that either. So, here we are. v4: * Update manpages and --help to reflect changes in 12/13 * No other changes v3: * Fixed validation of ifnames in 13/13. * No other changes. v2: * Numerous minor tweaks based on Stefano's feedback. * The "minor issues" aren't actually minor - they're hard to solve in C, remain. David Gibson (13): Makefile: Add missing PESTO_HEADERS variable conf: Use parameter instead of global in conf_nat() parse: Start splitting out parsing helpers conf: Remove duplicate parsing of -F option conf: Clean up conf_ip4_prefix() parse: Add helper to parse unsigned integer values parse: Move parse_port_range() to new parsing framework parse: Add helpers for parsing IP addresses conf: Move address configuration into helper function conf: Remove unnecessary mode checks from conf_addr() conf: Use new parsing tools to handle -a option fwd_rule: Allow "all" port specs to be combined with other options fwd_rule: Rewrite forward rule parsing using parse.c helpers Makefile | 22 +-- common.h | 3 + conf.c | 220 ++++++++++++++++------------- conf.h | 1 + fwd_rule.c | 400 ++++++++++++++++++++++++----------------------------- fwd_rule.h | 2 - inany.c | 70 +--------- inany.h | 3 - parse.c | 244 ++++++++++++++++++++++++++++++++ parse.h | 37 +++++ passt.1 | 33 +++-- util.c | 12 +- 12 files changed, 621 insertions(+), 426 deletions(-) create mode 100644 parse.c create mode 100644 parse.h -- 2.55.0

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[PATCH v3 00/13] Rework option parsing in preparation for destination remapping
by David Gibson 02 Jul '26

02 Jul '26

This was... a bit of a nightmare. It took way too long and went down a bunch of blind alleys. I'm not sure how much I like the final result: it's pleasingly terse in some cases, but in others it feels dangerously subtle, requiring a pretty careful understanding of the sequencing rules of C's &&, || and , operators. That said, while I was at many points ready to pack it in and hack my around the problems limiting the parsing for destination remapping, I couldn't really think of feasible way to do that either. So, here we are. v3: * Fixed validation of ifnames in 13/13. * No other changes. v2: * Numerous minor tweaks based on Stefano's feedback. * The "minor issues" aren't actually minor - they're hard to solve in C, remain. David Gibson (13): Makefile: Add missing PESTO_HEADERS variable conf: Use parameter instead of global in conf_nat() parse: Start splitting out parsing helpers conf: Remove duplicate parsing of -F option conf: Clean up conf_ip4_prefix() parse: Add helper to parse unsigned integer values parse: Move parse_port_range() to new parsing framework parse: Add helpers for parsing IP addresses conf: Move address configuration into helper function conf: Remove unnecessary mode checks from conf_addr() conf: Use new parsing tools to handle -a option fwd_rule: Allow "all" port specs to be combined with other options fwd_rule: Rewrite forward rule parsing using parse.c helpers Makefile | 22 +-- common.h | 3 + conf.c | 209 ++++++++++++++++------------ conf.h | 1 + fwd_rule.c | 400 ++++++++++++++++++++++++----------------------------- fwd_rule.h | 2 - inany.c | 70 +--------- inany.h | 3 - parse.c | 244 ++++++++++++++++++++++++++++++++ parse.h | 37 +++++ util.c | 12 +- 11 files changed, 600 insertions(+), 403 deletions(-) create mode 100644 parse.c create mode 100644 parse.h -- 2.54.0

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[PATCH v4 02/13] conf: Use parameter instead of global in conf_nat()
by David Gibson 02 Jul '26

02 Jul '26

conf_nat() takes a parameter @arg for the argument it's parsing. However on error we print instead optarg, the getopt() global. This happens to be the same thing at the time of the call, but it's not the right way to get to it. Signed-off-by: David Gibson <david(a)gibson.dropbear.id.au> --- conf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/conf.c b/conf.c index 4755a9f4..6ab8efec 100644 --- a/conf.c +++ b/conf.c @@ -1049,7 +1049,7 @@ static void conf_nat(const char *arg, struct in_addr *addr4, !IN4_IS_ADDR_MULTICAST(addr4)) return; - die("Invalid address to remap to host: %s", optarg); + die("Invalid address to remap to host: %s", arg); } /** -- 2.55.0

1 0

[PATCH v4 01/13] Makefile: Add missing PESTO_HEADERS variable
by David Gibson 02 Jul '26

02 Jul '26

In several places we use a PESTO_HEADERS variable, with all the headers that we need to build the pesto binary. However, we never define it. This looks like an error introduced by a bad rebase of the series introducing pesto before it was merged. It turns out the fact we didn't list the headers was the only reason we weren't getting unusedStructMember cppcheck warnings for pesto as we already do for passt and passt-repair. So, reinstate that suppression for pesto as well. Fixes: 02236db32625 ("pesto: Introduce stub configuration tool") Signed-off-by: David Gibson <david(a)gibson.dropbear.id.au> --- Makefile | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/Makefile b/Makefile index e8170e90..5ed0f702 100644 --- a/Makefile +++ b/Makefile @@ -55,6 +55,7 @@ PASST_HEADERS = arch.h arp.h bitmap.h checksum.h conf.h dhcp.h dhcpv6.h \ virtio.h vu_common.h QRAP_HEADERS = arp.h ip.h passt.h util.h PASST_REPAIR_HEADERS = linux_dep.h +PESTO_HEADERS = bitmap.h common.h fwd_rule.h inany.h ip.h log.h pesto.h serialise.h C := \#include <sys/random.h>\nint main(){int a=getrandom(0, 0, 0);} ifeq ($(shell printf "$(C)" | $(CC) -S -xc - -o - >/dev/null 2>&1; echo $$?),0) @@ -203,7 +204,8 @@ CPPCHECK_FLAGS = --std=c11 --error-exitcode=1 --enable=all --force \ else \ echo ""; \ fi) \ - --suppress=missingIncludeSystem + --suppress=missingIncludeSystem \ + --suppress=unusedStructMember cppcheck: passt.cppcheck passt-repair.cppcheck pesto.cppcheck @@ -212,10 +214,8 @@ cppcheck: passt.cppcheck passt-repair.cppcheck pesto.cppcheck $(CPPCHECK) $(CPPCHECK_FLAGS) $(BASE_CPPFLAGS) $^ passt.cppcheck: BASE_CPPFLAGS += -UPESTO -passt.cppcheck: CPPCHECK_FLAGS += --suppress=unusedStructMember passt.cppcheck: $(PASST_SRCS) $(PASST_HEADERS) seccomp.h -passt-repair.cppcheck: CPPCHECK_FLAGS += --suppress=unusedStructMember passt-repair.cppcheck: $(PASST_REPAIR_SRCS) $(PASST_REPAIR_HEADERS) seccomp_repair.h pesto.cppcheck: BASE_CPPFLAGS += -DPESTO -- 2.55.0

1 0

[PATCH 1/3] fwd_rule: Parse target adddresses for forwarding rules
by David Gibson 02 Jul '26

02 Jul '26

Extend the parsing of forwarding rules (-[tu]) to allow the destination address on the target side to be specified. For now just parse them, and give an error if we try to create rules with a specified target address. We'll implement the actual forwarding logic in another patch. Format (for either command line or pesto): -t 2222:192.0.2.1/2222 This should work along with all the other bits, that is, say: -t 192.0.2.1%eth0/2222-2225:192.0.2.2/22-25 FIXME: Ban for -[TU] for now FIXME: Check interaction with splice handling Signed-off-by: Stefano Brivio <sbrivio(a)redhat.com> [dwg: Syntax from Stefano's earlier draft, largely rewritten on top of new parsing helpers] Signed-off-by: David Gibson <david(a)gibson.dropbear.id.au> --- fwd_rule.c | 38 +++++++++++++++++++++++++++++++------- 1 file changed, 31 insertions(+), 7 deletions(-) diff --git a/fwd_rule.c b/fwd_rule.c index ca409eaf..e8abc884 100644 --- a/fwd_rule.c +++ b/fwd_rule.c @@ -378,14 +378,17 @@ int fwd_rule_add(struct fwd_table *fwd, const struct fwd_rule *new) * @first: First port to forward * @last: Last port to forward * @exclude: Bitmap of ports to exclude (may be NULL) - * @to: Port to translate @first to when forwarding + * @tgt_addr: Destination address on the target side + * @tgt_first: Destination port to use for @first on the traget side * @flags: Flags for forwarding entries */ static void fwd_rule_range_except(struct fwd_table *fwd, bool del, uint8_t proto, const union inany_addr *addr, const char *ifname, uint16_t first, uint16_t last, - const uint8_t *exclude, uint16_t to, + const uint8_t *exclude, + const union inany_addr *tgt_addr, + uint16_t tgt_first, uint8_t flags) { struct fwd_rule rule = { @@ -395,9 +398,17 @@ static void fwd_rule_range_except(struct fwd_table *fwd, bool del, .flags = flags, }; char rulestr[FWD_RULE_STRLEN]; - unsigned delta = to - first; + unsigned delta = tgt_first - first; unsigned base, i; + if (tgt_addr && !inany_is_unspecified(tgt_addr)) { + char astr[INANY_ADDRSTRLEN]; + + info("Target address: %s", + inany_ntop(tgt_addr, astr, sizeof(astr))); + die("Target address remapping not yet implemented"); + } + if (!addr) rule.flags |= FWD_DUAL_STACK_ANY; if (ifname) { @@ -458,14 +469,17 @@ enum fwd_port_chunk_kind { * @cursor: Parsing point (see parse.c) * @kindp: Updated with kind of chunk we parsed * @lrange: Updated with listening port range (for INCLUDE & EXCLUDE) + * @taddr: Updated with target address (for INCLUDE) * @trange: Updated with target port range (for INCLUDE) */ static bool parse_port_chunk(const char **cursor, enum fwd_port_chunk_kind *kindp, struct port_range *lrange, + union inany_addr *taddr, struct port_range *trange) { struct port_range lr = { 0 }, tr = { 0 }; + union inany_addr taddr_tmp = inany_any6; enum fwd_port_chunk_kind kind; const char *p = *cursor; @@ -481,6 +495,12 @@ static bool parse_port_chunk(const char **cursor, kind = CHUNK_INCLUDE; if (parse_literal(&p, ":")) { + const char *tgtspec = p; + + if (!parse_inany(&p, &taddr_tmp) || + !parse_literal(&p, "/")) + p = tgtspec; /* No target address, backtrack */ + if (!parse_port_range(&p, &tr)) return false; } else { @@ -492,6 +512,8 @@ static bool parse_port_chunk(const char **cursor, *kindp = kind; *lrange = lr; + if (taddr) + *taddr = taddr_tmp; if (trange) *trange = tr; *cursor = p; @@ -561,7 +583,7 @@ static void fwd_rule_parse_ports(struct fwd_table *fwd, bool del, uint8_t proto, /* Consider excluded ranges and "auto" in the first pass */ p = spec; do { - if (!parse_port_chunk(&p, &kind, &lrange, NULL)) + if (!parse_port_chunk(&p, &kind, &lrange, NULL, NULL)) goto bad; switch (kind) { @@ -586,8 +608,9 @@ static void fwd_rule_parse_ports(struct fwd_table *fwd, bool del, uint8_t proto, p = spec; do { struct port_range trange; + union inany_addr taddr; - if (!parse_port_chunk(&p, &kind, &lrange, &trange)) + if (!parse_port_chunk(&p, &kind, &lrange, &taddr, &trange)) goto bad; switch (kind) { @@ -604,7 +627,8 @@ static void fwd_rule_parse_ports(struct fwd_table *fwd, bool del, uint8_t proto, fwd_rule_range_except(fwd, del, proto, addr, ifname, lrange.first, lrange.last, - exclude, trange.first, flags); + exclude, &taddr, trange.first, + flags); break; default: goto bad; @@ -620,7 +644,7 @@ static void fwd_rule_parse_ports(struct fwd_table *fwd, bool del, uint8_t proto, fwd_rule_range_except(fwd, del, proto, addr, ifname, 1, NUM_PORTS - 1, exclude, - 1, flags | FWD_WEAK); + NULL, 1, flags | FWD_WEAK); } return; bad: -- 2.54.0

2 4

[PATCH 0/8] multithreading: Prepare data structures for concurrent queue pair workers
by Laurent Vivier 02 Jul '26

02 Jul '26

This series makes the passt data structures safe for concurrent access by multiple worker threads, each handling a different queue pair. It builds on the multiqueue series which threads the queue pair parameter through the network stack. The changes fall into three categories: 1. Per-queue-pair data isolation: - Convert packet pools (pool_tap4, pool_tap6) to per-queue-pair arrays - Convert L4 sequence batching arrays (tap4_l4, tap6_l4) similarly - Move flow and TCP timer state out of global/context structures into per-caller parameters 2. Stack-local buffers: - Move static iovec and virtqueue buffers onto the stack in tcp.c, tcp_vu.c, and udp_vu.c so each thread operates on its own copy 3. Locking for remaining shared state: - pthread_mutex on pre-opened socket pools (init_sock_pool4/6) - pthread_rwlock on the flow table, hash table, and free list, with read locks for lookups and write locks for mutations - _Thread_local for flow_new_entry so each thread independently tracks its in-progress allocation - Per-qpair filtering in flow_defer_handler() so each worker only processes its own flows Global operations that don't need per-queue-pair handling (tcp_payload_flush, socket pool refills) are guarded to run only on queue pair 0. Based-on: 20260616125130.1324274-1-lvivier(a)redhat.com Laurent Vivier (8): tap: Convert packet pools to per-queue-pair arrays for multiqueue tap: Make L4 sequence pools per-qpair for thread safety tcp: Make static buffers stack-local for thread safety udp_vu: Make virtqueue buffers stack-local for thread safety flow: Make flow timer per-caller for thread safety tcp: Make TCP timer state per-caller and guard global tasks tcp: Protect init socket pools with mutex for thread safety flow: Add mutex and per-qpair filtering to flow table operations flow.c | 68 +++++++++++++++++++++++++------- flow.h | 2 +- flow_table.h | 2 +- passt.c | 37 +++++++++-------- tap.c | 109 +++++++++++++++++++++++++++++---------------------- tap.h | 2 +- tcp.c | 64 +++++++++++++++++++----------- tcp.h | 9 +---- tcp_vu.c | 33 ++++++++++------ udp_vu.c | 4 +- vu_common.c | 2 +- 11 files changed, 203 insertions(+), 129 deletions(-) -- 2.54.0

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[PATCH v2 00/13] Rework option parsing in preparation for destination remapping
by David Gibson 02 Jul '26

02 Jul '26

This was... a bit of a nightmare. It took way too long and went down a bunch of blind alleys. I'm not sure how much I like the final result: it's pleasingly terse in some cases, but in others it feels dangerously subtle, requiring a pretty careful understanding of the sequencing rules of C's &&, || and , operators. That said, while I was at many points ready to pack it in and hack my around the problems limiting the parsing for destination remapping, I couldn't really think of feasible way to do that either. So, here we are. v2: * Numerous minor tweaks based on Stefano's feedback. * The "minor issues" aren't actually minor - they're hard to solve in C, remain. David Gibson (13): Makefile: Add missing PESTO_HEADERS variable conf: Use parameter instead of global in conf_nat() parse: Start splitting out parsing helpers conf: Remove duplicate parsing of -F option conf: Clean up conf_ip4_prefix() parse: Add helper to parse unsigned integer values parse: Move parse_port_range() to new parsing framework parse: Add helpers for parsing IP addresses conf: Move address configuration into helper function conf: Remove unnecessary mode checks from conf_addr() conf: Use new parsing tools to handle -a option fwd_rule: Allow "all" port specs to be combined with other options fwd_rule: Rewrite forward rule parsing using parse.c helpers Makefile | 22 +-- common.h | 3 + conf.c | 209 ++++++++++++++++------------ conf.h | 1 + fwd_rule.c | 398 +++++++++++++++++++++++------------------------------ fwd_rule.h | 2 - inany.c | 70 +--------- inany.h | 3 - parse.c | 244 ++++++++++++++++++++++++++++++++ parse.h | 37 +++++ util.c | 12 +- 11 files changed, 598 insertions(+), 403 deletions(-) create mode 100644 parse.c create mode 100644 parse.h -- 2.54.0

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[PATCH v3 02/13] conf: Use parameter instead of global in conf_nat()
by David Gibson 02 Jul '26

02 Jul '26

conf_nat() takes a parameter @arg for the argument it's parsing. However on error we print instead optarg, the getopt() global. This happens to be the same thing at the time of the call, but it's not the right way to get to it. Signed-off-by: David Gibson <david(a)gibson.dropbear.id.au> --- conf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/conf.c b/conf.c index 4755a9f4..6ab8efec 100644 --- a/conf.c +++ b/conf.c @@ -1049,7 +1049,7 @@ static void conf_nat(const char *arg, struct in_addr *addr4, !IN4_IS_ADDR_MULTICAST(addr4)) return; - die("Invalid address to remap to host: %s", optarg); + die("Invalid address to remap to host: %s", arg); } /** -- 2.54.0

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[PATCH v4 0/4] Add --dhcp-boot and --dhcp-opt options
by Anshu Kumari 01 Jul '26

01 Jul '26

This series adds support for custom DHCP options in passt, enabling network boot (PXE/UEFI HTTP Boot) and arbitrary DHCP option injection. Two new command-line flags are introduced: --dhcp-boot URL Sets the boot file URL (DHCP option 67 and the legacy boot file field) --dhcp-opt CODE,VALUE Sets any DHCP option by numeric code, with type-aware parsing per RFC 2132 The DHCP reply path is extended with option overload support (RFC 2132 option 52), allowing options to overflow into the file and sname fields when the standard options area is full. v4: Restructured series from 6 patches to 4: - 1/4 refactor fill_one() - 2/4 option overload - 3/4 --dhcp-opt with parser and man page - 4/4 --dhcp-boot with man page Anshu Kumari (4): dhcp: Refactor fill_one() to operate on a generic buffer dhcp: Add option overload dhcp: Add --dhcp-opt with option table and value parser conf: Add --dhcp-boot command-line option conf.c | 50 ++++++++- dhcp.c | 321 ++++++++++++++++++++++++++++++++++++++++++++++++++++---- dhcp.h | 2 + passt.1 | 49 +++++++++ passt.h | 6 ++ 5 files changed, 407 insertions(+), 21 deletions(-) -- 2.54.0

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