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* udp: Rename UDP listening socketsDavid Gibson2024-07-191-14/+11
| | | | | | | | | | EPOLL_TYPE_UDP is now only used for "listening" sockets; long lived sockets which can initiate new flows. Rename to EPOLL_TYPE_UDP_LISTEN and associated functions to match. Along with that, remove the .orig field from union udp_listen_epoll_ref, since it is now always true. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Remove rdelta port forwarding mapsDavid Gibson2024-07-191-36/+6
| | | | | | | | | | | | | | | | In addition to the struct fwd_ports used by both UDP and TCP to track port forwarding, UDP also included an 'rdelta' field, which contained the reverse mapping of the main port map. This was used so that we could properly direct reply packets to a forwarded packet where we change the destination port. This has now been taken over by the flow table: reply packets will match the flow of the originating packet, and that gives the correct ports on the originating side. So, eliminate the rdelta field, and with it struct udp_fwd_ports, which now has no additional information over struct fwd_ports. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Remove obsolete socket trackingDavid Gibson2024-07-191-91/+1
| | | | | | | | | Now that UDP datagrams are all directed via the flow table, we no longer use the udp_tap_map[ or udp_act[] arrays. Remove them and connected code. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Direct datagrams from host to guest via flow tableDavid Gibson2024-07-191-134/+51
| | | | | | | | | | | This replaces the last piece of existing UDP port tracking with the common flow table. Specifically use the flow table to direct datagrams from host sockets to the guest tap interface. Since this now requires a flow for every datagram, we add some logging if we encounter any datagrams for which we can't find or create a flow. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Find or create flows for datagrams from tap interfaceDavid Gibson2024-07-191-114/+97
| | | | | | | | | | | | | | | | | | | | | | Currently we create flows for datagrams from socket interfaces, and use them to direct "spliced" (socket to socket) datagrams. We don't yet match datagrams from the tap interface to existing flows, nor create new flows for them. Add that functionality, matching datagrams from tap to existing flows when they exist, or creating new ones. As with spliced flows, when creating a new flow from tap to socket, we create a new connected socket to receive reply datagrams attached to that flow specifically. We extend udp_flow_sock_handler() to handle reply packets bound for tap rather than another socket. For non-obvious reasons (perhaps increased stack usage?), this caused a failure for me when running under valgrind, because valgrind invoked rt_sigreturn which is not in our seccomp filter. Since we already allow rt_sigaction and others in the valgrind target, it seems reasonable to add rt_sigreturn as well. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Remove obsolete splice trackingDavid Gibson2024-07-191-47/+18
| | | | | | | | | | | | | | | Now that spliced datagrams are managed via the flow table, remove UDP_ACT_SPLICE_NS and UDP_ACT_SPLICE_INIT which are no longer used. With those removed, the 'ts' field in udp_splice_port is also no longer used. struct udp_splice_port now contains just a socket fd, so replace it with a plain int in udp_splice_ns[] and udp_splice_init[]. The latter are still used for tracking of automatic port forwarding. Finally, the 'splice' field of union udp_epoll_ref is no longer used so remove it as well. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Handle "spliced" datagrams with per-flow socketsDavid Gibson2024-07-191-261/+175
| | | | | | | | | | | | | | | | | | | | | When forwarding a datagram to a socket, we need to find a socket with a suitable local address to send it. Currently we keep track of such sockets in an array indexed by local port, but this can't properly handle cases where we have multiple local addresses in active use. For "spliced" (socket to socket) cases, improve this by instead opening a socket specifically for the target side of the flow. We connect() as well as bind()ing that socket, so that it will only receive the flow's reply packets, not anything else. We direct datagrams sent via that socket using the addresses from the flow table, effectively replacing bespoke addressing logic with the unified logic in fwd.c When we create the flow, we also take a duplicate of the originating socket, and use that to deliver reply datagrams back to the origin, again using addresses from the flow table entry. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Create flows for datagrams from originating socketsDavid Gibson2024-07-191-4/+165
| | | | | | | | | | | | | | | | This implements the first steps of tracking UDP packets with the flow table rather than its own (buggy) set of port maps. Specifically we create flow table entries for datagrams received from a socket (PIF_HOST or PIF_SPLICE). When splitting datagrams from sockets into batches, we group by the flow as well as splicesrc. This may result in smaller batches, but makes things easier down the line. We can re-optimise this later if necessary. For now we don't do anything else with the flow, not even match reply packets to the same flow. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Handle errors on UDP socketsDavid Gibson2024-07-171-0/+60
| | | | | | | | | | | | | | | | | | Currently we ignore all events other than EPOLLIN on UDP sockets. This means that if we ever receive an EPOLLERR event, we'll enter an infinite loop on epoll, because we'll never do anything to clear the error. Luckily that doesn't seem to have happened in practice, but it's certainly fragile. Furthermore changes in how we handle UDP sockets with the flow table mean we will start receiving error events. Add handling of EPOLLERR events. For now we just read the error from the error queue (thereby clearing the error state) and print a debug message. We can add more substantial handling of specific events in future if we want to. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp, tcp: Tweak handling of no_udp and no_tcp flagsDavid Gibson2024-07-171-2/+11
| | | | | | | | | | | | | | | | We abort the UDP socket handler if the no_udp flag is set. But if UDP was disabled we should never have had a UDP socket to trigger the handler in the first place. If we somehow did, ignoring it here isn't really going to help because aborting without doing anything is likely to lead to an epoll loop. The same is the case for the TCP socket and timer handlers and the no_tcp flag. Change these checks on the flag to ASSERT()s. Similarly add ASSERT()s to several other entry points to the protocol specific code which should never be called if the protocol is disabled. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Make udp_sock_recv staticDavid Gibson2024-07-171-2/+2
| | | | | | | | Through an oversight this was previously declared as a public function although it's only used in udp.c and there is no prototype in any header. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Consolidate datagram batchingDavid Gibson2024-07-051-90/+42
| | | | | | | | | | | | | | | | | | | When we receive datagrams on a socket, we need to split them into batches depending on how they need to be forwarded (either via a specific splice socket, or via tap). The logic to do this, is somewhat awkwardly split between udp_buf_sock_handler() itself, udp_splice_send() and udp_tap_send(). Move all the batching logic into udp_buf_sock_handler(), leaving udp_splice_send() to just send the prepared batch. udp_tap_send() reduces to just a call to tap_send_frames() so open-code that call in udp_buf_sock_handler(). This will allow separating the batching logic from the rest of the datagram forwarding logic, which we'll need for upcoming flow table support. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Move some more of sock_handler tasks into sub-functionsDavid Gibson2024-07-051-46/+84
| | | | | | | | | | | | | | | | | udp_buf_sock_handler(), udp_splice_send() and udp_tap_send loosely, do four things between them: 1. Receive some datagrams from a socket 2. Split those datagrams into batches depending on how they need to be sent (via tap or via a specific splice socket) 3. Prepare buffers for each datagram to send it onwards 4. Actually send it onwards Split (1) and (3) into specific helper functions. This isn't immediately useful (udp_splice_prepare(), in particular, is trivial), but it will make further reworks clearer. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Don't repeatedly initialise udp[46]_eth_hdrDavid Gibson2024-07-051-2/+3
| | | | | | | | | | | | Since we split our packet frame buffers into different pieces, we have a single buffer per IP version for the ethernet header, rather than one per frame. This makes sense since our ethernet header is alwaus the same. However we initialise those buffers udp[46]_eth_hdr inside a per frame loop. Pull that outside the loop so we just initialise them once. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Unify udp[46]_l2_iovDavid Gibson2024-07-051-23/+19
| | | | | | | | | | | | | | The only differences between these arrays are that udp4_l2_iov is pre-initialised to point to the IPv4 ethernet header, and IPv4 per-frame header and udp6_l2_iov points to the IPv6 versions. We already have to set up a bunch of headers per-frame, including updating udp[46]_l2_iov[i][UDP_IOV_PAYLOAD].iov_len. It makes more sense to adjust the IOV entries to point at the correct headers for the frame than to have two complete sets of iovecs. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Unify udp[46]_mh_spliceDavid Gibson2024-07-051-27/+20
| | | | | | | | | | | | | | | | | | We have separate mmsghdr arrays for splicing IPv4 and IPv6 packets, where the only difference is that they point to different sockaddr buffers for the destination address. Unify these by having the common array point at a sockaddr_inany as the address. This does mean slightly more work when we're about to splice, because we need to write the whole socket address, rather than just the port. However it removes 32 mmsghdr structures and we're going to need more flexibility constructing that target address for the flow table. Because future changes might mean that the address isn't always loopback, change the name of the common address from *_localname to udp_splicename. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Rename IOV and mmsghdr arraysDavid Gibson2024-07-051-34/+34
| | | | | | | | | | | | | | | | | | Make the salient points about these various arrays clearer with renames: * udp_l2_iov_sock and udp[46]_l2_mh_sock don't really have anything to do with L2. They are, however, specific to receiving not sending. Rename to udp_iov_recv and udp[46]_mh_recv. * udp[46]_l2_iov_tap is redundant - "tap" implies L2 and vice versa. Rename to udp[46]_l2_iov * udp[46]_localname are (for now) pre-populated with the local address but the more salient point is that these are the destination address for the splice arrays. Rename to udp[46]_splice_to Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Pass full epoll reference through more of sock handler pathDavid Gibson2024-07-051-30/+33
| | | | | | | | | | | | udp_buf_sock_handler() takes the epoll reference from the receiving socket, and passes the UDP relevant part on to several other functions. Future changes are going to need several different epoll types for UDP, and to pass that information through to some of those functions. To avoid extra noise in the patches making the real changes, change those functions now to take the full epoll reference, rather than just the UDP part. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* util: sock_l4() determine protocol from epoll type rather than the reverseDavid Gibson2024-07-051-6/+6
| | | | | | | | | | | | sock_l4() creates a socket of the given IP protocol number, and adds it to the epoll state. Currently it determines the correct tag for the epoll data based on the protocol. However, we have some future cases where we might want different semantics, and therefore epoll types, for sockets of the same protocol. So, change sock_l4() to take the epoll type as an explicit parameter, and determine the protocol from that. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Reduce scope of rport in udp_invert_portmap()2024_06_24.1ee2ecaStefano Brivio2024-06-241-2/+10
| | | | | | | | | | | | | | cppcheck 2.14 warns that the scope of the rport variable could be reduced: do that, as reverted commit c80fa6a6bb44 ("udp: Make rport calculation more local") did, but keep the temporary variable of in_port_t type, otherwise the sum gets promoted to int. While at it, add a comment explaining why we calculate rport like this instead of directly using the sum as array index. Reported-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
* Revert "udp: Make rport calculation more local"Stefano Brivio2024-06-241-1/+2
| | | | | | | | | | | This reverts commit c80fa6a6bb4415ad48f9e11424310875d0d99bc7, as it reintroduces the issue fixed by commit 1e6f92b995a9 ("udp: Fix 16-bit overflow in udp_invert_portmap()"). Reported-by: Laurent Jacquot <jk@lutty.net> Link: https://bugs.passt.top/show_bug.cgi?id=80 Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
* udp: Move management of udp[46]_localname into udp_splice_send()David Gibson2024-06-141-5/+4
| | | | | | | | | | | | | Mostly, udp_sock_handler() is independent of how the datagrams it processes will be forwarded (tap or splice). However, it also updates the msg_name fields for spliced sends, which doesn't really make sense here. Move it into udp_splice_send() which is all about spliced sends. This does potentially mean we'll update the field to the same value several times, but we're going to need this in future anyway: with the extensions the flow table allows, it might not be the same value each time after all. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Rework how we divide queued datagrams between sending methodsDavid Gibson2024-06-141-61/+87
| | | | | | | | | | | | | | | | | | | | | | | | | | | | udp_sock_handler() takes a number of datagrams from sockets that depending on their addresses could be forwarded either to the L2 interface ("tap") or to another socket ("spliced"). In the latter case we can also only send packets together if they have the same source port, and therefore are sent via the same socket. To reduce the total number of system calls we gather contiguous batches of datagrams with the same destination interface and socket where applicable. The determination of what the target is is made by udp_mmh_splice_port(). It returns the source port for splice packets and -1 for "tap" packets. We find batches by looking ahead in our queue until we find a datagram whose "splicefrom" port doesn't match the first in our current batch. udp_mmh_splice_port() is moderately expensive, and unfortunately we can call it twice on the same datagram: once as the (last + 1) entry in one batch (to check it's not in that batch), then again as the first entry in the next batch. Avoid this by keeping track of the "splice port" in the metadata structure, and filling it in one entry ahead of the one we're currently considering. This is a bit subtle, but not that hard. It will also generalise better when we have more complex possibilities based on the flow table. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Fold checking of splice flag into udp_mmh_splice_port()David Gibson2024-06-141-15/+16
| | | | | | | | | | | | | | | | | udp_mmh_splice_port() is used to determine if a UDP datagram can be "spliced" (forwarded via a socket instead of tap). We only invoke it if the origin socket has the 'splice' flag set. Fold the checking of the flag into the helper itself, which makes the caller simpler. It does mean we have a loop looking for a batch of spliceable or non-spliceable packets even in the case where the flag is clear. This shouldn't be that expensive though, since each call to udp_mmh_splice_port() will return without accessing memory in that case. In any case we're going to need a similar loop in more cases with upcoming flow table work. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* vhost-user: compare mode MODE_PASTA and not MODE_PASSTLaurent Vivier2024-06-131-1/+1
| | | | | | | | | | As we are going to introduce the MODE_VU that will act like the mode MODE_PASST, compare to MODE_PASTA rather than to add a comparison to MODE_VU when we check for MODE_PASST. Signed-off-by: Laurent Vivier <lvivier@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: rename udp_sock_handler() to udp_buf_sock_handler()Laurent Vivier2024-06-131-3/+3
| | | | | | | | | We are going to introduce a variant of the function to use vhost-user buffers rather than passt internal buffers. Signed-off-by: Laurent Vivier <lvivier@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: refactor UDP header update functionsLaurent Vivier2024-06-131-26/+34
| | | | | | | | | | | | | | | | | | This commit refactors the udp_update_hdr4() and udp_update_hdr6() functions to improve code portability by replacing the udp_meta_t parameter with more specific parameters for the IPv4 and IPv6 headers (iphdr/ipv6hdr) and the source socket address (sockaddr_in/sockaddr_in6). It also moves the tap_hdr_update() function call inside the udp_tap_send() function not to have to pass the TAP header to udp_update_hdr4() and udp_update_hdr6() This refactor reduces complexity by making the functions more modular and ensuring that each function operates on more narrowly scoped data structures. This will facilitate future backend introduction like vhost-user. Signed-off-by: Laurent Vivier <lvivier@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Make rport calculation more localDavid Gibson2024-06-071-2/+1
| | | | | | | | | cppcheck 2.14.1 complains about the rport variable not being in as small as scope as it could be. It's also only used once, so we might as well just open code the calculation for it. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Single buffer for IPv4, IPv6 headers and metadataDavid Gibson2024-05-021-77/+55
| | | | | | | | | | | | | | | Currently we have separate arrays for IPv4 and IPv6 which contain the headers for guest-bound packets, and also the originating socket address. We can combine these into a single array of "metadata" structures with space for both pre-cooked IPv4 and IPv6 headers, as well as shared space for the tap specific header and socket address (using sockaddr_inany). Because we're using IOVs to separately address the pieces of each frame, these structures don't need to be packed to keep the headers contiguous so we can more naturally arrange for the alignment we want. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Use the same buffer for the L2 header for all framesDavid Gibson2024-05-021-21/+15
| | | | | | | | | | Currently each tap-bound frame buffer has room for its own ethernet header. However the ethernet header is always the same for such frames, so now that we're indirectly referencing the ethernet header via iov, we can use a single buffer for all of them. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Share payload buffers between IPv4 and IPv6David Gibson2024-05-021-59/+67
| | | | | | | | | | | | | | | Currently the IPv4 and IPv6 paths unnecessarily use different buffers for the UDP payload. Now that we're handling the various pieces of the UDP packets with an iov, we can split the payload part of the buffers off into its own array shared between IPv4 and IPv6. As well as saving a little memory, this allows the payload buffers to be neatly page aligned. With the buffers merged, udp[46]_l2_iov_sock contain exactly the same thing as each other and can also be merged. Likewise udp[46]_iov_splice can be merged together. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Explicitly set checksum in guest-bound UDP headersDavid Gibson2024-05-021-3/+4
| | | | | | | | | | | | | | | | | | For IPv4, UDP checksums are optional and can just be set to 0. udp_update_hdr4() ignores the checksum field entirely. Since these are set to 0 during startup, this works as intended for now. However, we'd like to share payload and UDP header buffers betweem IPv4 and IPv6, which does calculate UDP checksums. Therefore, for robustness, we should explicitly set the checksum field to 0 for guest-bound UDP packets. In the tap_udp4_send() slow path, however, we do allow IPv4 UDP checksums to be calculated as a compile time option. For consistency, use the same thing in the udp_update_hdr4() path, which will typically initialize to 0, but calculate a real checksum if configured to do so. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Combine initialisation of IPv4 and IPv6 iovsDavid Gibson2024-05-021-61/+53
| | | | | | | | | | We're going to introduce more sharing between the IPv4 and IPv6 buffer structures. Prepare for this by combinng the initialisation functions. While we're at it remove the misleading "sock" from the name since these initialise both tap side and sock side structures. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Split tap-bound UDP packets into multiple buffers using io vectorDavid Gibson2024-05-021-25/+49
| | | | | | | | | | | | | | | | | | | When sending to the tap device, currently we assemble the headers and payload into a single contiguous buffer. Those are described by a single struct iovec, then a batch of frames is sent to the device with tap_send_frames(). In order to better integrate the IPv4 and IPv6 paths, we want the IP header in a different buffer that might not be contiguous with the payload. To prepare for that, split the UDP packet into an iovec of buffers. We use the same split that Laurent recently introduced for TCP for convenience. This removes the last use of tap_hdr_len_(), tap_frame_base() and tap_frame_len(), so remove those too. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* iov: Helper macro to construct iovs covering existing variables or fieldsDavid Gibson2024-05-021-4/+3
| | | | | | | | | | | Laurent's recent changes mean we use IO vectors much more heavily in the TCP code. In many of those cases, and few others around the code base, individual iovs of these vectors are constructed to exactly cover existing variables or fields. We can make initializing such iovs shorter and clearer with a macro for the purpose. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* treewide: Standardise variable names for various packet lengthsDavid Gibson2024-05-021-13/+13
| | | | | | | | | | | | | | | | | | At various points we need to track the lengths of a packet including or excluding various different sets of headers. We don't always use the same variable names for doing so. Worse in some places we use the same name for different things: e.g. tcp_fill_headers[46]() use ip_len for the length including the IP headers, but then tcp_send_flag() which calls it uses it to mean the IP payload length only. To improve clarity, standardise on these names: dlen: L4 protocol payload length ("data length") l4len: plen + length of L4 protocol header l3len: l4len + length of IPv4/IPv6 header l2len: l3len + length of L2 (ethernet) header Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* checksum: Make csum_ip4_header() take a host endian lengthDavid Gibson2024-05-021-1/+1
| | | | | | | | | | | | | | csum_ip4_header() takes the packet length as a network endian value. In general it's very error-prone to pass non-native-endian values as a raw integer. It's particularly bad here because this differs from other checksum functions (e.g. proto_ipv4_header_psum()) which take host native lengths. It turns out all the callers have easy access to the native endian value, so switch it to use host order like everything else. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* tap: Split tap specific and L2 (ethernet) headersDavid Gibson2024-05-021-9/+14
| | | | | | | | | | | | | | In some places (well, actually only UDP now) we use struct tap_hdr to represent both tap backend specific and L2 ethernet headers. Handling these together seemed like a good idea at the time, but Laurent's changes in the TCP code working towards vhost-user support suggest that treating them separately is more useful, more often. Alter struct tap_hdr to represent only the TAP backend specific headers. Updated related helpers and the UDP code to match. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Correctly look up outbound socket with port remappingsDavid Gibson2024-04-251-2/+3
| | | | | | | | | | | | | | | | | | | | | | | Commit bb9bf0bb ("tcp, udp: Don't precompute port remappings in epoll references") changed the epoll reference for UDP sockets to include the bound port as seen by the socket itself, rather than the bound port it would be translated to on the guest side. As a side effect, it also means that udp_tap_map[] is indexed by the bound port on the host side, rather than on the guest side. This is consistent and a good idea, however we forgot to account for it when finding the correct outgoing socket for packets originating in the guest. This means that if forwarding UDP inbound with a port number change, reply packets would be misdirected. Fix this by applying the reverse mapping before looking up the socket in udp_tap_handler(). While we're at it, use 'port' directly instead of 'uref.port' in udp_sock_init(). Those now always have the same value - failing to realise that is the same error as above. Reported-by: Laurent Jacquot <jk@lutty.net> Link: https://bugs.passt.top/show_bug.cgi?id=87 Fixes: bb9bf0bb8f57 ("tcp, udp: Don't precompute port remappings in epoll references") Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Translate source address of resolver only for DNS remapped queriesStefano Brivio2024-03-181-6/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Paul reports that if pasta is configured with --dns-forward, and the container queries a resolver which is configured on the host directly, without using the address given for --dns-forward, we'll translate the source address of the response pretending it's coming from the address passed as --dns-forward, and the client will discard the reply. That is, $ cat /etc/resolv.conf 198.51.100.1 $ pasta --config-net --dns-forward 192.0.2.1 nslookup passt.top will not work, because we change the source address of the reply from 198.51.100.1 to 192.0.2.1. But the client contacted 198.51.100.1, and it's from that address that it expects an answer. Add a PORT_DNS_FWD flag for tap-facing ports, which is triggered by activity in the opposite direction as the other flags. If the tap-facing port was seen sending a DNS query that was remapped, we'll remap the source address of the response, otherwise we'll leave it unaffected. Reported-by: Paul Holzinger <pholzing@redhat.com> Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
* tap: Rename tap_iov_{base,len}David Gibson2024-03-141-4/+4
| | | | | | | | | | | These two functions are typically used to calculate values to go into the iov_base and iov_len fields of a struct iovec. They don't have to be used for that, though. Rename them in terms of what they actually do: calculate the base address and total length of the complete frame, including both L2 and tap specific headers. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* tap: Extend tap_send_frames() to allow multi-buffer framesDavid Gibson2024-03-141-1/+1
| | | | | | | | | | | tap_send_frames() takes a vector of buffers and requires exactly one frame per buffer. We have future plans where we want to have multiple buffers per frame in some circumstances, so extend tap_send_frames() to take the number of buffers per frame as a parameter. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> [sbrivio: Improve comment to rembufs calculation] Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Use existing helper for UDP checksum on inbound IPv6 packetsDavid Gibson2024-03-131-4/+1
| | | | | | | | | | | Currently we open code the calculation of the UDP checksum in udp_update_hdr6(). We calling a helper to handle the IPv6 pseudo-header, and preset the checksum field to 0 so an uninitialised value doesn't get folded in. We already have a helper to do this: csum_udp6() which we use in some slow paths. Use it here as well. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Avoid unnecessary pointer in udp_update_hdr4()David Gibson2024-03-131-9/+9
| | | | | | | | | We carry around the source address as a pointer to a constant struct in_addr. But it's silly to carry around a 4 or 8 byte pointer to a 4 byte IPv4 address. Just copy the IPv4 address around by value. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Re-order udp_update_hdr[46] for clarity and brevityDavid Gibson2024-03-131-26/+14
| | | | | | | | | | | | | | | The order of things in these functions is a bit odd for historical reasons. We initialise some IP header fields early, the more later after making some tests. Likewise we declare some variables without initialisation, but then unconditionally set them to values we could calculate at the start of the function. Previous cleanups have removed the reasons for some of these choices, so reorder for clarity, and where possible move the first assignment into an initialiser. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Pass data length explicitly to to udp_update_hdr[46]David Gibson2024-03-131-12/+16
| | | | | | | | | | | | These functions take an index to the L2 buffer whose header information to update. They use that for two things: to locate the buffer pointer itself, and to retrieve the length of the received message from the paralllel udp[46]_l2_mh_sock array. The latter is arguably a failure to separate concerns. Change these functions to explicitly take a buffer pointer and payload length as parameters. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Consistent port variable names in udp_update_hdr[46]David Gibson2024-03-131-18/+18
| | | | | | | | | In these functions we have 'dstport' for the destination port, but 'src_port' for the source port. Change the latter to 'srcport' for consistency. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Refactor udp_sock[46]_iov_init()David Gibson2024-03-131-52/+50
| | | | | | | | | | | | Each of these functions have 3 essentially identical loops in a row. Merge the loops into a single common udp_sock_iov_init() function, calling udp_sock[46]_iov_init_one() helpers to initialize each "slot" in the various parallel arrays. This is slightly neater now, and more naturally allows changes we want to make where more initialization will become common between IPv4 and IPv6. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* tap: make tap_update_mac() genericLaurent Vivier2024-03-061-2/+2
| | | | | | | | | | Use ethhdr rather than tap_hdr. Signed-off-by: Laurent Vivier <lvivier@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Message-ID: <20240303135114.1023026-9-lvivier@redhat.com> Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* checksum: introduce functions to compute the header part checksum for TCP/UDPLaurent Vivier2024-03-061-8/+10
| | | | | | | | | | | | | | | The TCP and UDP checksums are computed using the data in the TCP/UDP payload but also some informations in the IP header (protocol, length, source and destination addresses). We add two functions, proto_ipv4_header_psum() and proto_ipv6_header_psum(), to compute the checksum of the IP header part. Signed-off-by: Laurent Vivier <lvivier@redhat.com> Message-ID: <20240303135114.1023026-8-lvivier@redhat.com> Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
generated by cgit v1.2.3 (git 2.25.1) at 2024-09-19 16:55:54 +0000