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* netlink: Add support to fetch default gateway from multipath routesStefano Brivio2024-02-091-3/+48
| | | | | | | | | | | | | | If the default route for a given IP version is a multipath one, instead of refusing to start because there's no RTA_GATEWAY attribute in the set returned by the kernel, we can just pick one of the paths. To make this somewhat less arbitrary, pick the path with the highest weight, if weights differ. Reported-by: Ed Santiago <santiago@redhat.com> Link: https://github.com/containers/podman/issues/20927 Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
* netlink: Fetch most specific (longest prefix) address in nl_addr_get()2023_12_30.f091893Stefano Brivio2023-12-301-5/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This happened in most cases implicitly before commit eff3bcb24547 ("netlink: Split nl_addr() into separate operation functions"): while going through results from netlink, we would only copy an address into the provided return buffer if no address had been picked yet. Because of the insertion logic in the kernel (ipv6_link_dev_addr()), the first returned address would also be the one added last, and, in case of a Linux guest using a DHCPv6 client as well as SLAAC, that would be the address assigned via DHCPv6, because SLAAC happens before the DHCPv6 exchange. The effect of, instead, picking the last returned address (first assigned) is visible when passt or pasta runs nested, given that, by default, they advertise a prefix for SLAAC usage, plus an address via DHCPv6. The first level (L1 guest) would get a /64 address by means of SLAAC, and a /128 address via DHCPv6, the latter matching the address on the host. The second level (L2 guest) would also get two addresses: a /64 via SLAAC (same prefix as the host), and a /128 via DHCPv6, matching the the L1 SLAAC-assigned address, not the one obtained via DHCPv6. That is, none of the L2 addresses would match the address on the host. The whole point of having a DHCPv6 server is to avoid (implicit) NAT when possible, though. Fix this in a more explicit way than the behaviour we initially had: pick the first address among the set of most specific ones, by comparing prefix lengths. Do this for IPv4 and for link-local addresses, too, to match in any case the implementation of the default source address selection. Reported-by: Yalan Zhang <yalzhang@redhat.com> Fixes: eff3bcb24547 ("netlink: Split nl_addr() into separate operation functions") Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* treewide: Use 'z' length modifier for size_t/ssize_t conversionsStefano Brivio2023-12-021-1/+1
| | | | | | | | Types size_t and ssize_t are not necessarily long, it depends on the architecture. Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
* netlink: Sequence numbers are actually 32 bits wideStefano Brivio2023-11-071-10/+10
| | | | | | | | | | | | | | | | | | | | | Harmless, as we use sequence numbers monotonically anyway, but now clang-tidy reports: /home/sbrivio/passt/netlink.c:155:7: error: format specifies type 'unsigned short' but the argument has type '__u32' (aka 'unsigned int') [clang-diagnostic-format,-warnings-as-errors] nh->nlmsg_seq, seq); ^ /home/sbrivio/passt/log.h:26:7: note: expanded from macro 'die' err(__VA_ARGS__); \ ^~~~~~~~~~~ /home/sbrivio/passt/log.h:19:34: note: expanded from macro 'err' ^~~~~~~~~~~ Suppressed 222820 warnings (222816 in non-user code, 4 NOLINT). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 1 warning treated as error make: *** [Makefile:255: clang-tidy] Error 1 Fixes: 9d4ab98d538f ("netlink: Add nl_do() helper for simple operations with error checking") Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* cppcheck: Make many pointers constDavid Gibson2023-10-041-3/+3
| | | | | | | | | Newer versions of cppcheck (as of 2.12.0, at least) added a warning for pointers which could be declared to point at const data, but aren't. Based on that, make many pointers throughout the codebase const. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* pasta: Strip RTA_PREFSRC when copying routes to the namespace2023_08_23.a7e4bfbDavid Gibson2023-08-231-1/+14
| | | | | | | | | | | | | | | | | | | | | Host routes can include a preferred source address (RTA_PREFSRC), which must be one of the host's addresses. However when using pasta with -a the namespace might be given a different address, not on the host. This seems to occur pretty routinely depending on the network configuration systems in place on the host. With --config-net we will try to copy host routes to the namespace. If one of those includes an RTA_PREFSRC, but the namespace doesn't have the host address, this will fail with -EINVAL, causing pasta to fail. Fix this by stripping off RTA_PREFSRC attributes from routes as we copy them to the namespace. This is by no means infallible, bit it should at least handle common cases for the time being. Link: https://bugs.passt.top/show_bug.cgi?id=71 Link: https://github.com/containers/podman/pull/19699#issuecomment-1688769287 Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* netlink: Set IFA_ADDRESS, not just IFA_LOCAL, while adding IPv4 addressesStefano Brivio2023-08-231-0/+1
| | | | | | | | | Otherwise, we actually configure the address, but it's not usable because no local route is added by the kernel. Link: https://github.com/containers/podman/pull/19699 Fixes: cfe7509e5c16 ("netlink: Use struct in_addr for IPv4 addresses, not bare uint32_t") Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* netlink: Don't propagate host address expiry to the containerDavid Gibson2023-08-161-1/+3
| | | | | | | | | | | | | | | | | | | | | | | When we copy addresses from the host to the container in nl_addr_dup(), we copy all the address's attributes, including IFA_CACHEINFO, which controls the address's lifetime. If the host address is managed by, for example, DHCP, it will typically have a finite lifetime. When we copy that lifetime to the pasta container, that lifetime will remain, meaning the kernel will eventually remove the address, typically some hours later. The container, however, won't have the DHCP client or whatever was managing and maintaining the address in the host, so it will just lose connectivity. Long term, we may want to monitor host address changes and reflect them to the guest. But for now, we just want to take a snapshot of the host's address and set those in the container permanently. We can accomplish that by stripping off the IFA_CACHEINFO attribute as we copy addresses. Link: https://github.com/containers/podman/issues/19405 Link: https://bugs.passt.top/show_bug.cgi?id=70 Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* netlink: Correctly calculate attribute length for address messagesDavid Gibson2023-08-161-2/+2
| | | | | | | | | | | | In nl_addr_get() and nl_addr_dup() we step the attributes attached to each RTM_NEWADDR message with a loop initialised with IFA_RTA() and RTM_PAYLOAD() macros. RTM_PAYLOAD(), however is for RTM_NEWROUTE messages (struct rtmsg), not RTM_NEWADDR messages (struct ifaddrmsg). Consequently it miscalculates the size and means we can skip some attributes. Switch to IFA_PAYLOAD() which we should be using here. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* netlink: Remove redundant check on nlmsg_typeDavid Gibson2023-08-161-3/+0
| | | | | | | | | | | In the loop within nl_addr_dup() we check and skip for any messages that aren't of type RTM_NEWADDR. This is a leftover that was missed in the recent big netlink cleanup. In fact we already check for the message type in the nl_foreach_oftype() macro, so the explicit test is redudant. Remove it. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* netlink: Propagate errors for "dup" operationsDavid Gibson2023-08-041-12/+28
| | | | | | | | | | | | | | | | We now detect errors on netlink "set" operations while configuring the pasta namespace with --config-net. However in many cases rather than a simple "set" we use a more complex "dup" function to copy configuration from the host to the namespace. We're not yet properly detecting and reporting netlink errors for that case. Change the "dup" operations to propagate netlink errors to their caller, pasta_ns_conf() and report them there. Link: https://bugs.passt.top/show_bug.cgi?id=60 Signed-off-by: David Gibson <david@gibson.dropbear.id.au> [sbrivio: Minor formatting changes in pasta_ns_conf()] Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* netlink: Propagate errors for "dump" operationsDavid Gibson2023-08-041-4/+15
| | | | | | | | | | | | | | Currently if we receive any netlink errors while discovering network configuration from the host, we'll just ignore it and carry on. This might lead to cryptic error messages later on, or even silent misconfiguration. We now have the mechanisms to detect errors from get/dump netlink operations. Propgate these errors up to the callers and report them usefully. Link: https://bugs.passt.top/show_bug.cgi?id=60 Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* netlink: Always process all responses to a netlink requestDavid Gibson2023-08-041-24/+22
| | | | | | | | | | | | | | | | | | | | | | A single netlink request can result in multiple response datagrams. We process multiple response datagrams in some circumstances, but there are cases where we exit early and will leave remaining datagrams in the queue. These will be flushed in nl_send() before we send another request. This is confusing, and not what we need to reliably check for errors from netlink operations. So, instead, make sure we always process all the response datagrams whenever we send a request (excepting fatal errors). In most cases this is just a matter of avoiding early exits from nl_foreach loops. nl_route_dup() is a bit trickier, because we need to retain all the routes we're going to try to copy in a single buffer. Here we instead use a secondary buffer to flush any remaining datagrams, and report an error if there are any additional routes in those datagrams . Link: https://bugs.passt.top/show_bug.cgi?id=67 Link: https://bugs.passt.top/show_bug.cgi?id=60 Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* netlink: Propagate errors for "set" operationsDavid Gibson2023-08-041-9/+17
| | | | | | | | | | | | | | | Currently if anything goes wrong while we're configuring the namespace network with --config-net, we'll just ignore it and carry on. This might lead to a silently unconfigured or misconfigured namespace environment. For simple "set" operations based on nl_do() we can now detect failures reported via netlink. Propagate those errors up to pasta_ns_conf() and report them usefully. Link: https://bugs.passt.top/show_bug.cgi?id=60 Signed-off-by: David Gibson <david@gibson.dropbear.id.au> [sbrivio: Minor formatting changes in pasta_ns_conf()] Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* netlink: Add nl_foreach_oftype to filter response message typesDavid Gibson2023-08-041-15/+14
| | | | | | | | | | | | | | | In most cases where processing response messages, we expect only one type of message (excepting NLMSG_DONE or NLMSG_ERROR), and so we need a test and continue to skip anything else. Add a helper macro to do this. This also fixes a bug in nl_get_ext_if() where we didn't have such a test and if we got a message other than RTM_NEWROUTE we would have parsed its contents as nonsense. Also add a warning message if we get such an unexpected message type, which could be useful for debugging if we ever hit it. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* netlink: Split nl_req() to allow processing multiple response datagramsDavid Gibson2023-08-041-68/+113
| | | | | | | | | | | | | | | | | | | | | | | | | Currently nl_req() sends the request, and receives a single response datagram which we then process. However, a single request can result in multiple response datagrams. That happens nearly all the time for DUMP requests, where the 'DONE' message usually comes in a second datagram after the NEW{LINK|ADDR|ROUTE} messages. It can also happen if there are just too many objects to dump in a single datagram. Allow our netlink code to process multiple response datagrams by splitting nl_req() into three different helpers: nl_send() just sends a request, without getting a response. nl_status() checks a single message to see if it indicates the end of the reponses for our request. nl_next() moves onto the next response message, whether it's in a datagram we already received or we need to recv() a new one. We also add a 'for'-style macro to use these to step through every response message to a request across multiple datagrams. While we're at it, be more thourough with checking that our sequence numbers are in sync. Link: https://bugs.passt.top/show_bug.cgi?id=67 Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* netlink: Clearer reasoning about the netlink response buffer sizeDavid Gibson2023-08-041-1/+8
| | | | | | | | | | | | | Currently we set NLBUFSIZ large enough for 8192 netlink headers (128kiB in total), and reference netlink(7). However netlink(7) says nothing about reponse buffer sizes, and the documents which do reference 8192 *bytes* not 8192 headers. Update NLBUFSIZ to 64kiB with a more detailed rationale. Link: https://bugs.passt.top/show_bug.cgi?id=67 Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* netlink: Add nl_do() helper for simple operations with error checkingDavid Gibson2023-08-041-12/+47
| | | | | | | | | | | | | | | | | | | | | | | So far we never checked for errors reported on netlink operations via NLMSG_ERROR messages. This has led to several subtle and tricky to debug situations which would have been obvious if we knew that certain netlink operations had failed. Introduce a nl_do() helper that performs netlink "do" operations (that is making a single change without retreiving complex information) with much more thorough error checking. As well as returning an error code if we get an NLMSG_ERROR message, we also check for unexpected behaviour in several places. That way if we've made a mistake in our assumptions about how netlink works it should result in a clear error rather than some subtle misbehaviour. We update those calls to nl_req() that can use the new wrapper to do so. We will extend those to better handle errors in future. We don't touch non-"do" operations for now, those are a bit trickier. Link: https://bugs.passt.top/show_bug.cgi?id=60 Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* netlink: Fill in netlink header fields from nl_req()David Gibson2023-08-041-84/+42
| | | | | | | | | | Currently netlink functions need to fill in a full netlink header, as well as a payload then call nl_req() to submit that to the kernel. It makes things a bit terser if we just give the relevant header fields as parameters to nl_req() and have it complete the header. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* netlink: Treat send() or recv() errors as fatalDavid Gibson2023-08-041-19/+17
| | | | | | | | | | | | | | | Errors on send() or recv() calls on a netlink socket don't indicate errors with the netlink operations we're attempting, but rather that something's gone wrong with the mechanics of netlink itself. We don't really expect this to ever happen, and if it does, it's not clear what we could to to recover. So, treat errors from these calls as fatal, rather than returning the error up the stack. This makes handling failures in the callers of nl_req() simpler. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* netlink: Start sequence number from 1 instead of 0David Gibson2023-08-041-1/+1
| | | | | | | | | | | | | | | | | Netlink messages have a sequence number that's used to match requests to responses. It mostly doesn't matter what it is as long as it monotonically increases, so we just use a global counter which we advance with each request. However, we start this counter at 0, so our very first request has sequence number 0, which is usually reserved for asynchronous messages from the kernel which aren't in response to a specific request. Since we don't (for now) use such async messages, this doesn't really matter, but it's not good practce. So start the sequence at 1 instead. Link: https://bugs.passt.top/show_bug.cgi?id=67 Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* netlink: Make nl_*_dup() use a separate datagram for each requestDavid Gibson2023-08-041-23/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | nl_req() is designed to handle a single netlink request message: it only receives a single reply datagram for the request, and only waits for a single NLMSG_DONE or NLMSG_ERROR message at the beginning to clear out things from previous requests. However, in both nl_addr_dup() and nl_route_dup() we can send multiple request messages as a single datagram, with a single nl_req() call. This can easily mean that the replies nl_req() collects get out of sync with requests. We only get away with this because after we call these functions we don't make any netlink calls where we need to parse the replies. This is fragile, so alter nl_*_dup() to make an nl_req() call for each address it is adding in the target namespace. For nl_route_dup() this fixes an additional minor problem: because routes can have dependencies, some of the route add requests might fail on the first attempt, so we need to repeat the requests a number of times. When we did that, we weren't updating the sequence number on each new attempt. This works, but not updating the sequence number for each new request isn't ideal. Now that we're making the requests one at a time, it's easier to make sure we update the sequence number each time. Link: https://bugs.passt.top/show_bug.cgi?id=67 Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* netlink: Explicitly pass netlink sockets to operationsDavid Gibson2023-08-041-39/+53
| | | | | | | | | | | | | | All the netlink operations currently implicitly use one of the two global netlink sockets, sometimes depending on an 'ns' parameter. Change them all to explicitly take the socket to use (or two sockets to use in the case of the *_dup() functions). As well as making these functions strictly more general, it makes the callers easier to follow because we're passing a socket variable with a name rather than an unexplained '0' or '1' for the ns parameter. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> [sbrivio: Minor formatting changes in pasta_ns_conf()] Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* netlink: Use struct in_addr for IPv4 addresses, not bare uint32_tDavid Gibson2023-08-041-6/+6
| | | | | | | | This improves consistency with IPv6 and makes it harder to misuse these as some other sort of value. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* netlink: Split nl_route() into separate operation functionsDavid Gibson2023-08-041-89/+148
| | | | | | | | | | nl_route() can perform 3 quite different operations based on the 'op' parameter. Split this into separate functions for each one. This requires more lines of code, but makes the internal logic of each operation much easier to follow. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* netlink: Split nl_addr() into separate operation functionsDavid Gibson2023-08-041-93/+139
| | | | | | | | | | | | | | | nl_addr() can perform three quite different operations based on the 'op' parameter, each of which uses a different subset of the parameters. Split them up into a function for each operation. This does use more lines of code, but the overlap wasn't that great, and the separated logic is much easier to follow. It's also clearer in the callers what we expect the netlink operations to do, and what information it uses. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> [sbrivio: Minor formatting fixes in pasta_ns_conf()] Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* netlink: Split up functionality of nl_link()David Gibson2023-08-041-59/+82
| | | | | | | | | | | | | | | | | | | | | | | nl_link() performs a number of functions: it can bring links up, set MAC address and MTU and also retrieve the existing MAC. This makes for a small number of lines of code, but high conceptual complexity: it's quite hard to follow what's going on both in nl_link() itself and it's also not very obvious which function its callers are intending to use. Clarify this, by splitting nl_link() into nl_link_up(), nl_link_set_mac(), and nl_link_get_mac(). The first brings up a link, optionally setting the MTU, the others get or set the MAC address. This fixes an arguable bug in pasta_ns_conf(): it looks as though that was intended to retrieve the guest MAC whether or not c->pasta_conf_ns is set. However, it only actually does so in the !c->pasta_conf_ns case: the fact that we set up==1 means we would only ever set, never get, the MAC in the nl_link() call in the other path. We get away with this because the MAC will quickly be discovered once we receive packets on the tap interface. Still, it's neater to always get the MAC address here. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* netlink: Use correct interface index in NL_SET mode2023_06_27.289301bDavid Gibson2023-06-271-2/+2
| | | | | | | | | | | | | | | | | | nl_addr() and nl_route() take an 'op' selector which affects a number of parameters to the netlink call. Unfortunately when we introduced this option a bug was introduced so that we always use the interface index for the host side, rather than the one for the pasta namespace. Really, the entire interface to nl_addr() and nl_route() is pretty bad: it's tightly coupled with the use cases of its callers. This is a minimal fix which doesn't address that, but also doesn't make it significantly worse. Link: https://bugs.passt.top/show_bug.cgi?id=59 Fixes: 2fe046185634 ("netlink: Add functionality to copy routes from outer namespace") Fixes: e89da3cf03b2 ("netlink: Add functionality to copy addresses from outer namespace") Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* netlink: Add functionality to copy addresses from outer namespaceStefano Brivio2023-05-231-15/+47
| | | | | | | | | | | | | | | | | | | | Similarly to what we've just done with routes, support NL_DUP for addresses (currently not exposed): nl_addr() can optionally copy mulitple addresses to the target namespace, by fixing up data from the dump with appropriate flags and interface index, and repeating it back to the kernel on the socket opened in the target namespace. Link-local addresses are not copied: the family is set to AF_UNSPEC, which means the kernel will ignore them. Same for addresses from a mismatching address (pre-4.19 kernels without support for NETLINK_GET_STRICT_CHK). Ignore IFA_LABEL attributes by changing their type to IFA_UNSPEC, because in general they will report mismatching names, and we don't really need to use labels as we already know the interface index. Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
* netlink: Add functionality to copy routes from outer namespaceStefano Brivio2023-05-231-17/+54
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of just fetching the default gateway and configuring a single equivalent route in the target namespace, on 'pasta --config-net', it might be desirable in some cases to copy the whole set of routes corresponding to a given output interface. For instance, in: https://github.com/containers/podman/issues/18539 IPv4 Default Route Does Not Propagate to Pasta Containers on Hetzner VPSes configuring the default gateway won't work without a gateway-less route (specifying the output interface only), because the default gateway is, somewhat dubiously, not on the same subnet as the container. This is a similar case to the one covered by commit 7656a6f88882 ("conf: Adjust netmask on mismatch between IPv4 address/netmask and gateway"), and I'm not exactly proud of that workaround. We also have: https://bugs.passt.top/show_bug.cgi?id=49 pasta does not work with tap-style interface for which, eventually, we should be able to configure a gateway-less route in the target namespace. Introduce different operation modes for nl_route(), including a new NL_DUP one, not exposed yet, which simply parrots back to the kernel the route dump for a given interface from the outer namespace, fixing up flags and interface indices on the way, and requesting to add the same routes in the target namespace, on the interface we manage. For n routes we want to duplicate, send n identical netlink requests including the full dump: routes might depend on each other and the kernel processes RTM_NEWROUTE messages sequentially, not atomically, and repeating the full dump naturally resolves dependencies without the need to actually calculate them. I'm not kidding, it actually works pretty well. Link: https://github.com/containers/podman/issues/18539 Link: https://bugs.passt.top/show_bug.cgi?id=49 Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
* netlink: Fix comment about response buffer size for nl_req()Stefano Brivio2023-05-231-1/+1
| | | | | | Fixes: fde8004ab0b4 ("netlink: Use 8 KiB * netlink message header size as response buffer") Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
* passt: Relicense to GPL 2.0, or any later versionStefano Brivio2023-04-061-1/+1
| | | | | | | | | | | | | | | | | | | In practical terms, passt doesn't benefit from the additional protection offered by the AGPL over the GPL, because it's not suitable to be executed over a computer network. Further, restricting the distribution under the version 3 of the GPL wouldn't provide any practical advantage either, as long as the passt codebase is concerned, and might cause unnecessary compatibility dilemmas. Change licensing terms to the GNU General Public License Version 2, or any later version, with written permission from all current and past contributors, namely: myself, David Gibson, Laine Stump, Andrea Bolognani, Paul Holzinger, Richard W.M. Jones, Chris Kuhn, Florian Weimer, Giuseppe Scrivano, Stefan Hajnoczi, and Vasiliy Ulyanov. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* Work around weird false positives with cppcheck-2.9.1David Gibson2023-03-211-1/+1
| | | | | | | | | | | | | | | | | | Commit 89e38f55 "treewide: Fix header includes to build with musl" added extra #includes to work with musl. Unfortunately with the cppcheck version I'm using (cppcheck-2.9-1.fc37.x86_64 in Fedora 37) this causes weird false positives: specifically cppcheck seems to hit a #error in <bits/unistd.h> complaining about including it directly instead of via <unistd.h> (which is not something we're doing). I have no idea why that would be happening; but I'm guessing it has to be a bug in the cpp implementation in that cppcheck version. In any case, it's possible to work around this by moving the include of <unistd.h> before the include of <signal.h>. So, do that. Fixes: 89e38f55405d ("treewide: Fix header includes to build with musl") Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* treewide: Fix header includes to build with muslChris Kuhn2023-03-091-0/+1
| | | | | | | | | | | | | | | Roughly inspired from a patch by Chris Kuhn: fix up includes so that we can build against musl: glibc is more lenient as headers generally include a larger amount of other headers. Compared to the original patch, I only included what was needed directly in C files, instead of adding blanket includes in local header files. It's a bit more involved, but more consistent with the current (not ideal) situation. Reported-by: Chris Kuhn <kuhnchris+github@kuhnchris.eu> Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
* netlink: Use 8 KiB * netlink message header size as response bufferStefano Brivio2023-03-091-6/+9
| | | | | | | | | | | | | | | | | | | ...instead of BUFSIZ. On musl, BUFSIZ is 1024, so we'll typically truncate the response to the request we send in nl_link(). It's usually 8192 or more with glibc. There doesn't seem to be any macro defining the rtnetlink maximum message size, and iproute2 just hardcodes 1024 * 1024 for the receive buffer, but the example in netlink(7) makes somewhat sense, looking at the kernel implementation. It's not very clean, but we're very unlikely to hit that limit, and if we do, we'll find out painlessly, because NLA_OK() will tell us right away. Reported-by: Chris Kuhn <kuhnchris+passt@kuhnchris.eu> Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
* convert all remaining err() followed by exit() to die()Laine Stump2023-02-161-2/+1
| | | | | | | | This actually leaves us with 0 uses of err(), but someone could want to use it in the future, so we may as well leave it around. Signed-off-by: Laine Stump <laine@redhat.com> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* pasta: do not leak netlink sock into childPaul Holzinger2023-02-121-2/+2
| | | | | | | | | | | | | | When spawning a child command with pasta command... pasta should not leak fds that it opened. Only the fds that were already open should be given to the child. Run `pasta --config-net -- ls -l /proc/self/fd` from a terminal where only stdin/out/err are open. The fd 3 was opend by ls to read the /proc/self/fd dir. But fd 5 is the netlink socket that was opend in pasta. To prevent such a leak we will open the socket with SOCK_CLOEXEC. Signed-off-by: Paul Holzinger <pholzing@redhat.com> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* conf: Bind inbound ports with CAP_NET_BIND_SERVICE before isolate_user()Stefano Brivio2022-10-151-19/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Even if CAP_NET_BIND_SERVICE is granted, we'll lose the capability in the target user namespace as we isolate the process, which means we're unable to bind to low ports at that point. Bind inbound ports, and only those, before isolate_user(). Keep the handling of outbound ports (for pasta mode only) after the setup of the namespace, because that's where we'll bind them. To this end, initialise the netlink socket for the init namespace before isolate_user() as well, as we actually need to know the addresses of the upstream interface before binding ports, in case they're not explicitly passed by the user. As we now call nl_sock_init() twice, checking its return code from conf() twice looks a bit heavy: make it exit(), instead, as we can't do much if we don't have netlink sockets. While at it: - move the v4_only && v6_only options check just after the first option processing loop, as this is more strictly related to option parsing proper - update the man page, explaining that CAP_NET_BIND_SERVICE is *not* the preferred way to bind ports, because passt and pasta can be abused to allow other processes to make effective usage of it. Add a note about the recommended sysctl instead - simplify nl_sock_init_do() now that it's called once for each case Reported-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* netlink: Disable duplicate address detection for configured IPv6 addressStefano Brivio2022-10-151-0/+3
| | | | | | | | | | | | | | | | | | With default options, when we pass --config-net, the IPv6 address is actually going to be recycled from the init namespace, so it is in fact duplicated, but duplicate address detection has no way to find out. With a different configured address, that's not the case, but anyway duplicate address detection will be unable to see this. In both cases, we're wasting time for nothing. Pass the IFA_F_NODAD flag as we configure globally scoped IPv6 addresses via netlink. Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
* Move logging functions to a new file, log.cStefano Brivio2022-10-141-0/+1
| | | | | | | | Logging to file is going to add some further complexity that we don't want to squeeze into util.c. Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
* Avoid ugly 'end' members in netlink structuresDavid Gibson2022-09-291-9/+10
| | | | | | | | | | | | | | We use a number of complex structures to format messages to send to netlink. In some cases we add imaginary 'end' members not because they actually mean something on the wire, but so that we can use offsetof() on the member to determine the relevant size. Adding extra things to the structures for this is kinda nasty. We can use a different construct with offsetof and sizeof to avoid them. As a bonus this removes some cppcheck warnings about unused struct members. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* cppcheck: Reduce scope of some variablesDavid Gibson2022-09-291-2/+1
| | | | | | | Minor style improvement suggested by cppcheck. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* Separately locate external interfaces for IPv4 and IPv6David Gibson2022-07-301-72/+7
| | | | | | | | | | | | | | | | | Now that the back end allows passt/pasta to use different external interfaces for IPv4 and IPv6, use that to do the right thing in the case that the host has IPv4 and IPv6 connectivity via different interfaces. If the user hasn't explicitly chosen an interface, separately search for a suitable external interface for each protocol. As a bonus, this substantially simplifies the external interface probe. It also eliminates a subtle confusing case where in some circumstances we would pick the first interface in interface index order, and sometimes in order of routes returned from netlink. On some network configurations that could cause tests to fail, because the logic in the tests was subtly different (it always used route order). Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
* netlink: In nl_addr() and nl_route(), don't return before set requestStefano Brivio2022-05-011-2/+2
| | | | | Fixes: 22ed4467a413 ("treewide: Unchecked return value from library, CWE-252") Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* treewide: Unchecked return value from library, CWE-252Stefano Brivio2022-04-071-15/+25
| | | | | | | All instances were harmless, but it might be useful to have some debug messages here and there. Reported by Coverity. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* treewide: Mark constant references as constStefano Brivio2022-03-291-2/+2
| | | | Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* netlink: Avoid left-over bytes in request on MTU configurationStefano Brivio2022-02-231-4/+7
| | | | | | | | | When nl_link() configures the MTU, it shouldn't send extra bytes, otherwise we'll get a kernel warning: netlink: 4 bytes leftover after parsing attributes in process `pasta'. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* netlink: Fix swapped v4/v6-only flags in external interface detectionStefano Brivio2022-01-261-2/+2
| | | | | | | The effect of this typo became visible in an IPv6-only environment, where passt wouldn't work at all. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* tcp, netlink, HAS{BYTES_ACKED,MIN_RTT,GETRANDOM} and NETLINK_GET_STRICT_CHKStefano Brivio2022-01-261-2/+7
| | | | | | | | | | | | | | | | tcpi_bytes_acked and tcpi_min_rtt are only available on recent kernel versions: provide fall-back paths (incurring some grade of performance penalty). Support for getrandom() was introduced in Linux 3.17 and glibc 2.25: provide an alternate mechanism for that as well, reading from /dev/random. Also check if NETLINK_GET_STRICT_CHK is defined before using it: it's not strictly needed, we'll filter out irrelevant results from netlink anyway. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* passt: Drop <linux/ipv6.h> include, carry own ipv6hdr and opt_hdr definitionsStefano Brivio2022-01-261-1/+0
| | | | | | | This is the only remaining Linux-specific include -- drop it to avoid clang-tidy warnings and to make code more portable. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-05 03:33:01 +0000