kernel.git/drivers/net/wireguard/selftest, branch linux-rolling-stable

wireguard: allowedips: add WGALLOWEDIP_F_REMOVE_ME flag

2025-05-27T07:06:19Z

The current netlink API for WireGuard does not directly support removal of allowed ips from a peer. A user can remove an allowed ip from a peer in one of two ways: 1. By using the WGPEER_F_REPLACE_ALLOWEDIPS flag and providing a new list of allowed ips which omits the allowed ip that is to be removed. 2. By reassigning an allowed ip to a "dummy" peer then removing that peer with WGPEER_F_REMOVE_ME. With the first approach, the driver completely rebuilds the allowed ip list for a peer. If my current configuration is such that a peer has allowed ips 192.168.0.2 and 192.168.0.3 and I want to remove 192.168.0.2 the actual transition looks like this. [192.168.0.2, 192.168.0.3] <-- Initial state [] <-- Step 1: Allowed ips removed for peer [192.168.0.3] <-- Step 2: Allowed ips added back for peer This is true even if the allowed ip list is small and the update does not need to be batched into multiple WG_CMD_SET_DEVICE requests, as the removal and subsequent addition of ips is non-atomic within a single request. Consequently, wg_allowedips_lookup_dst and wg_allowedips_lookup_src may return NULL while reconfiguring a peer even for packets bound for ips a user did not intend to remove leading to unintended interruptions in connectivity. This presents in userspace as failed calls to sendto and sendmsg for UDP sockets. In my case, I ran netperf while repeatedly reconfiguring the allowed ips for a peer with wg. /usr/local/bin/netperf -H 10.102.73.72 -l 10m -t UDP_STREAM -- -R 1 -m 1024 send_data: data send error: No route to host (errno 113) netperf: send_omni: send_data failed: No route to host While this may not be of particular concern for environments where peers and allowed ips are mostly static, systems like Cilium manage peers and allowed ips in a dynamic environment where peers (i.e. Kubernetes nodes) and allowed ips (i.e. pods running on those nodes) can frequently change making WGPEER_F_REPLACE_ALLOWEDIPS problematic. The second approach avoids any possible connectivity interruptions but is hacky and less direct, requiring the creation of a temporary peer just to dispose of an allowed ip. Introduce a new flag called WGALLOWEDIP_F_REMOVE_ME which in the same way that WGPEER_F_REMOVE_ME allows a user to remove a single peer from a WireGuard device's configuration allows a user to remove an ip from a peer's set of allowed ips. This enables incremental updates to a device's configuration without any connectivity blips or messy workarounds. A corresponding patch for wg extends the existing `wg set` interface to leverage this feature. $ wg set wg0 peer allowed-ips +192.168.88.0/24,-192.168.0.1/32 When '+' or '-' is prepended to any ip in the list, wg clears WGPEER_F_REPLACE_ALLOWEDIPS and sets the WGALLOWEDIP_F_REMOVE_ME flag on any ip prefixed with '-'. Signed-off-by: Jordan Rife [Jason: minor style nits, fixes to selftest, bump of wireguard-tools version] Signed-off-by: Jason A. Donenfeld Link: https://patch.msgid.link/20250521212707.1767879-5-Jason@zx2c4.com Signed-off-by: Paolo Abeni

wireguard: allowedips: remove redundant selftest call

2024-11-19T03:32:27Z

This commit fixes a useless call issue detected by Coverity (CID 1508092). The call to horrible_allowedips_lookup_v4 is unnecessary as its return value is never checked. Signed-off-by: Dheeraj Reddy Jonnalagadda Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") Signed-off-by: Jason A. Donenfeld Link: https://patch.msgid.link/20241117212030.629159-3-Jason@zx2c4.com Signed-off-by: Jakub Kicinski

wireguard: allowedips: expand maximum node depth

2023-08-07T19:26:57Z

In the allowedips self-test, nodes are inserted into the tree, but it generated an even amount of nodes, but for checking maximum node depth, there is of course the root node, which makes the total number necessarily odd. With two few nodes added, it never triggered the maximum depth check like it should have. So, add 129 nodes instead of 128 nodes, and do so with a more straightforward scheme, starting with all the bits set, and shifting over one each time. Then increase the maximum depth to 129, and choose a better name for that variable to make it clear that it represents depth as opposed to bits. Cc: stable@vger.kernel.org Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") Signed-off-by: Jason A. Donenfeld Link: https://lore.kernel.org/r/20230807132146.2191597-2-Jason@zx2c4.com Signed-off-by: Jakub Kicinski

treewide: use get_random_u32_inclusive() when possible

2022-11-18T01:18:02Z

These cases were done with this Coccinelle: @@ expression H; expression L; @@ - (get_random_u32_below(H) + L) + get_random_u32_inclusive(L, H + L - 1) @@ expression H; expression L; expression E; @@ get_random_u32_inclusive(L, H - + E - - E ) @@ expression H; expression L; expression E; @@ get_random_u32_inclusive(L, H - - E - + E ) @@ expression H; expression L; expression E; expression F; @@ get_random_u32_inclusive(L, H - - E + F - + E ) @@ expression H; expression L; expression E; expression F; @@ get_random_u32_inclusive(L, H - + E + F - - E ) And then subsequently cleaned up by hand, with several automatic cases rejected if it didn't make sense contextually. Reviewed-by: Kees Cook Reviewed-by: Greg Kroah-Hartman Reviewed-by: Jason Gunthorpe # for infiniband Signed-off-by: Jason A. Donenfeld

treewide: use get_random_u32_below() instead of deprecated function

2022-11-18T01:15:15Z

This is a simple mechanical transformation done by: @@ expression E; @@ - prandom_u32_max + get_random_u32_below (E) Reviewed-by: Kees Cook Reviewed-by: Greg Kroah-Hartman Acked-by: Darrick J. Wong # for xfs Reviewed-by: SeongJae Park # for damon Reviewed-by: Jason Gunthorpe # for infiniband Reviewed-by: Russell King (Oracle) # for arm Acked-by: Ulf Hansson # for mmc Signed-off-by: Jason A. Donenfeld

treewide: use get_random_bytes() when possible

2022-10-11T23:42:58Z

The prandom_bytes() function has been a deprecated inline wrapper around get_random_bytes() for several releases now, and compiles down to the exact same code. Replace the deprecated wrapper with a direct call to the real function. This was done as a basic find and replace. Reviewed-by: Greg Kroah-Hartman Reviewed-by: Kees Cook Reviewed-by: Yury Norov Reviewed-by: Christophe Leroy # powerpc Acked-by: Jakub Kicinski Signed-off-by: Jason A. Donenfeld

treewide: use get_random_{u8,u16}() when possible, part 1

2022-10-11T23:42:58Z

Rather than truncate a 32-bit value to a 16-bit value or an 8-bit value, simply use the get_random_{u8,u16}() functions, which are faster than wasting the additional bytes from a 32-bit value. This was done mechanically with this coccinelle script: @@ expression E; identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; typedef u16; typedef __be16; typedef __le16; typedef u8; @@ ( - (get_random_u32() & 0xffff) + get_random_u16() | - (get_random_u32() & 0xff) + get_random_u8() | - (get_random_u32() % 65536) + get_random_u16() | - (get_random_u32() % 256) + get_random_u8() | - (get_random_u32() >> 16) + get_random_u16() | - (get_random_u32() >> 24) + get_random_u8() | - (u16)get_random_u32() + get_random_u16() | - (u8)get_random_u32() + get_random_u8() | - (__be16)get_random_u32() + (__be16)get_random_u16() | - (__le16)get_random_u32() + (__le16)get_random_u16() | - prandom_u32_max(65536) + get_random_u16() | - prandom_u32_max(256) + get_random_u8() | - E->inet_id = get_random_u32() + E->inet_id = get_random_u16() ) @@ identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; typedef u16; identifier v; @@ - u16 v = get_random_u32(); + u16 v = get_random_u16(); @@ identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; typedef u8; identifier v; @@ - u8 v = get_random_u32(); + u8 v = get_random_u8(); @@ identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; typedef u16; u16 v; @@ - v = get_random_u32(); + v = get_random_u16(); @@ identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; typedef u8; u8 v; @@ - v = get_random_u32(); + v = get_random_u8(); // Find a potential literal @literal_mask@ expression LITERAL; type T; identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; position p; @@ ((T)get_random_u32()@p & (LITERAL)) // Examine limits @script:python add_one@ literal << literal_mask.LITERAL; RESULT; @@ value = None if literal.startswith('0x'): value = int(literal, 16) elif literal[0] in '123456789': value = int(literal, 10) if value is None: print("I don't know how to handle %s" % (literal)) cocci.include_match(False) elif value < 256: coccinelle.RESULT = cocci.make_ident("get_random_u8") elif value < 65536: coccinelle.RESULT = cocci.make_ident("get_random_u16") else: print("Skipping large mask of %s" % (literal)) cocci.include_match(False) // Replace the literal mask with the calculated result. @plus_one@ expression literal_mask.LITERAL; position literal_mask.p; identifier add_one.RESULT; identifier FUNC; @@ - (FUNC()@p & (LITERAL)) + (RESULT() & LITERAL) Reviewed-by: Greg Kroah-Hartman Reviewed-by: Kees Cook Reviewed-by: Yury Norov Acked-by: Jakub Kicinski Acked-by: Toke Høiland-Jørgensen # for sch_cake Signed-off-by: Jason A. Donenfeld

wireguard: ratelimiter: disable timings test by default

2022-09-20T18:26:13Z

A previous commit tried to make the ratelimiter timings test more reliable but in the process made it less reliable on other configurations. This is an impossible problem to solve without increasingly ridiculous heuristics. And it's not even a problem that actually needs to be solved in any comprehensive way, since this is only ever used during development. So just cordon this off with a DEBUG_ ifdef, just like we do for the trie's randomized tests, so it can be enabled while hacking on the code, and otherwise disabled in CI. In the process we also revert 151c8e499f47. Fixes: 151c8e499f47 ("wireguard: ratelimiter: use hrtimer in selftest") Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") Signed-off-by: Jason A. Donenfeld Signed-off-by: Jakub Kicinski

wireguard: allowedips: don't corrupt stack when detecting overflow

2022-08-02T20:47:50Z

In case push_rcu() and related functions are buggy, there's a WARN_ON(len >= 128), which the selftest tries to hit by being tricky. In case it is hit, we shouldn't corrupt the kernel's stack, though; otherwise it may be hard to even receive the report that it's buggy. So conditionalize the stack write based on that WARN_ON()'s return value. Note that this never *actually* happens anyway. The WARN_ON() in the first place is bounded by IS_ENABLED(DEBUG), and isn't expected to ever actually hit. This is just a debugging sanity check. Additionally, hoist the constant 128 into a named enum, MAX_ALLOWEDIPS_BITS, so that it's clear why this value is chosen. Suggested-by: Linus Torvalds Link: https://lore.kernel.org/all/CAHk-=wjJZGA6w_DxA+k7Ejbqsq+uGK==koPai3sqdsfJqemvag@mail.gmail.com/ Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") Signed-off-by: Jason A. Donenfeld Signed-off-by: Jakub Kicinski

wireguard: ratelimiter: use hrtimer in selftest

2022-08-02T20:47:50Z

Using msleep() is problematic because it's compared against ratelimiter.c's ktime_get_coarse_boottime_ns(), which means on systems with slow jiffies (such as UML's forced HZ=100), the result is inaccurate. So switch to using schedule_hrtimeout(). However, hrtimer gives us access only to the traditional posix timers, and none of the _COARSE variants. So now, rather than being too imprecise like jiffies, it's too precise. One solution would be to give it a large "range" value, but this will still fire early on a loaded system. A better solution is to align the timeout to the actual coarse timer, and then round up to the nearest tick, plus change. So add the timeout to the current coarse time, and then schedule_hrtimer() until the absolute computed time. This should hopefully reduce flakes in CI as well. Note that we keep the retry loop in case the entire function is running behind, because the test could still be scheduled out, by either the kernel or by the hypervisor's kernel, in which case restarting the test and hoping to not be scheduled out still helps. Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") Suggested-by: Thomas Gleixner Signed-off-by: Jason A. Donenfeld Signed-off-by: Jakub Kicinski