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* Split tap_ip_send() into IPv4 and IPv6 specific functionsDavid Gibson2022-10-191-8/+2
| | | | | | | | | | | | | | | | | | | The IPv4 and IPv6 paths in tap_ip_send() have very little in common, and it turns out that every caller (statically) knows if it is using IPv4 or IPv6. So split into separate tap_ip4_send() and tap_ip6_send() functions. Use a new tap_l2_hdr() function for the very small common part. While we're there, make some minor cleanups: - We were double writing some fields in the IPv6 header, so that it temporary matched the pseudo-header for checksum calculation. With recent checksum reworks, this isn't neccessary any more. - We don't use any IPv4 header options, so use some sizeof() constructs instead of some open coded values for header length. - The comment used to say that the flow label was for TCP over IPv6, but in fact the only thing we used it for was DHCPv6 over UDP traffic Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* icmp: Set sin6_scope_id for outbound ICMPv6 echo requestsStefano Brivio2022-10-151-0/+1
| | | | | | | | | | | If we ping a link-local address, we need to pass this to sendto(), as it will obviously fail with -EINVAL otherwise. If we ping other addresses, it's probably a good idea anyway to specify the configured outbound interface here. Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
* conf, tcp, udp: Allow specification of interface to bind toStefano Brivio2022-10-151-2/+2
| | | | | | | | | | | | | | | | Since kernel version 5.7, commit c427bfec18f2 ("net: core: enable SO_BINDTODEVICE for non-root users"), we can bind sockets to interfaces, if they haven't been bound yet (as in bind()). Introduce an optional interface specification for forwarded ports, prefixed by %, that can be passed together with an address. Reported use case: running local services that use ports we want to have externally forwarded: https://github.com/containers/podman/issues/14425 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>
* clang-tidy: Remove duplicate #include from icmp.cDavid Gibson2022-09-291-1/+0
| | | | | Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* icmp: Correct off by one errors dealing with number of echo request ids2022_09_24.8978f65David Gibson2022-09-241-2/+3
| | | | | | | | | | ICMP echo request and reply packets include a 16-bit 'id' value. We have some arrays indexed by this id value. Unfortunately we size those arrays with USHRT_MAX (65535) when they need to be sized by the total number of id values (65536). This could lead to buffer overruns. Resize the arrays correctly, using a new define for the purpose. Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
* conf, tcp, udp: Allow address specification for forwarded portsStefano Brivio2022-05-011-2/+3
| | | | | | | | | | | | | This feature is available in slirp4netns but was missing in passt and pasta. Given that we don't do dynamic memory allocation, we need to bind sockets while parsing port configuration. This means we need to process all other options first, as they might affect addressing and IP version support. It also implies a minor rework of how TCP and UDP implementations bind sockets. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* treewide: Unchecked return value from library, CWE-252Stefano Brivio2022-04-071-4/+9
| | | | | | | 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>
* tap, tcp, udp, icmp: Cut down on some oversized buffersStefano Brivio2022-03-291-2/+10
| | | | | | | | | The existing sizes provide no measurable differences in throughput and packet rates at this point. They were probably needed as batched implementations were not complete, but they can be decreased quite a bit now. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* treewide: Mark constant references as constStefano Brivio2022-03-291-7/+8
| | | | Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* treewide: Packet abstraction with mandatory boundary checksStefano Brivio2022-03-291-14/+14
| | | | | | | | | | | | | | | | | | | | Implement a packet abstraction providing boundary and size checks based on packet descriptors: packets stored in a buffer can be queued into a pool (without storage of its own), and data can be retrieved referring to an index in the pool, specifying offset and length. Checks ensure data is not read outside the boundaries of buffer and descriptors, and that packets added to a pool are within the buffer range with valid offset and indices. This implies a wider rework: usage of the "queueing" part of the abstraction mostly affects tap_handler_{passt,pasta}() functions and their callees, while the "fetching" part affects all the guest or tap facing implementations: TCP, UDP, ICMP, ARP, NDP, DHCP and DHCPv6 handlers. Suggested-by: Stefan Hajnoczi <stefanha@redhat.com> 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>
* passt: Fix build with gcc 7, use std=c99, enable some more Clang checkersStefano Brivio2021-10-211-20/+22
| | | | | | | | | | | | | | Unions and structs, you all have names now. Take the chance to enable bugprone-reserved-identifier, cert-dcl37-c, and cert-dcl51-cpp checkers in clang-tidy. Provide a ffsl() weak declaration using gcc built-in. Start reordering includes, but that's not enough for the llvm-include-order checker yet. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* passt: Add clang-tidy Makefile target and test, take care of warningsStefano Brivio2021-10-201-2/+2
| | | | | | | Most are just about style and form, but a few were actually serious mistakes (NDP-related). Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* tap: Completely de-serialise input message batchesStefano Brivio2021-09-271-7/+13
| | | | | | | | | | | | | Until now, messages would be passed to protocol handlers in a single batch only if they happened to be dequeued in a row. Packets interleaved between different connections would result in multiple calls to the same protocol handler for a single connection. Instead, keep track of incoming packet descriptors, arrange them in sequences, and call protocol handlers only as we completely sorted input messages in batches. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* icmp: Work around possible failure on bind() due to e.g. broken SELinux policyStefano Brivio2021-07-261-4/+14
| | | | | | | | | | | | | | | If we can't bind() ping sockets, the echo identifier sent out from the socket won't be the original one seen from the tap. Binding a ping socket doesn't require any security capability, but it might still fail due to a broken SELinux policy, see for example: https://bugzilla.redhat.com/show_bug.cgi?id=1848929 Track the ICMP echo identifier as part of the epoll reference for the socket and replace it in the reply on mismatch. We won't send out the original identifier as sent from the guest, but still better than missing replies. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* tap: Fill the IPv6 flow label field to represent flow associationStefano Brivio2021-07-261-2/+2
| | | | | | | | | This isn't optional: TCP streams must carry a unique, hard-to-guess, non-zero label for each direction. Linux, probably among others, will otherwise refuse to associate packets in a given stream to the same connection. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* passt: Add PASTA mode, major reworkStefano Brivio2021-07-171-59/+126
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | PASTA (Pack A Subtle Tap Abstraction) provides quasi-native host connectivity to an otherwise disconnected, unprivileged network and user namespace, similarly to slirp4netns. Given that the implementation is largely overlapping with PASST, no separate binary is built: 'pasta' (and 'passt4netns' for clarity) both link to 'passt', and the mode of operation is selected depending on how the binary is invoked. Usage example: $ unshare -rUn # echo $$ 1871759 $ ./pasta 1871759 # From another terminal # udhcpc -i pasta0 2>/dev/null # ping -c1 pasta.pizza PING pasta.pizza (64.190.62.111) 56(84) bytes of data. 64 bytes from 64.190.62.111 (64.190.62.111): icmp_seq=1 ttl=255 time=34.6 ms --- pasta.pizza ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt min/avg/max/mdev = 34.575/34.575/34.575/0.000 ms # ping -c1 spaghetti.pizza PING spaghetti.pizza(2606:4700:3034::6815:147a (2606:4700:3034::6815:147a)) 56 data bytes 64 bytes from 2606:4700:3034::6815:147a (2606:4700:3034::6815:147a): icmp_seq=1 ttl=255 time=29.0 ms --- spaghetti.pizza ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt min/avg/max/mdev = 28.967/28.967/28.967/0.000 ms This entails a major rework, especially with regard to the storage of tracked connections and to the semantics of epoll(7) references. Indexing TCP and UDP bindings merely by socket proved to be inflexible and unsuitable to handle different connection flows: pasta also provides Layer-2 to Layer-2 socket mapping between init and a separate namespace for local connections, using a pair of splice() system calls for TCP, and a recvmmsg()/sendmmsg() pair for UDP local bindings. For instance, building on the previous example: # ip link set dev lo up # iperf3 -s $ iperf3 -c ::1 -Z -w 32M -l 1024k -P2 | tail -n4 [SUM] 0.00-10.00 sec 52.3 GBytes 44.9 Gbits/sec 283 sender [SUM] 0.00-10.43 sec 52.3 GBytes 43.1 Gbits/sec receiver iperf Done. epoll(7) references now include a generic part in order to demultiplex data to the relevant protocol handler, using 24 bits for the socket number, and an opaque portion reserved for usage by the single protocol handlers, in order to track sockets back to corresponding connections and bindings. A number of fixes pertaining to TCP state machine and congestion window handling are also included here. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* icmp: Implement lazy bind for ping socketsStefano Brivio2021-05-211-2/+10
| | | | | | | | | It turns out that binding ICMP/ICMPv6 echo sockets takes a long time. Instead of binding all of them (one for each possible echo identification number, that is, 2^17) at start-up, bind them as ICMP/ICMPv6 packets are sent by the guest. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* icmp: Implement ping tracking based on echo identifiersStefano Brivio2021-05-211-24/+33
| | | | | | | | | Open and bind a socket for each possible ICMP/ICMPv6 echo identifier, and add a tracking mechanism. Otherwise, multiple pings in parallel won't work, and a single ping to a different destination would make an existing ping sequence stop working. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* icmp: Warn if "ping" socket can't be opened, don't failStefano Brivio2021-05-101-2/+16
| | | | | | | | If net.ipv4.ping_group_range doesn't include our PID, we'll fail to open sockets for ICMP and ICMPv6 echo. Warn instead of exiting, this is not fatal. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp, passt: Introduce socket packet buffer, avoid getsockname() for UDPStefano Brivio2021-04-301-1/+3
| | | | | | | | | | This is in preparation for scatter-gather IO on the UDP receive path: save a getsockname() syscall by setting a flag if we get the numbering of all bound sockets in a strict sequence (expected, in practice) and repurpose the tap buffer to be also a socket receive buffer, passing it down to protocol handlers. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* udp: Connection tracking for ephemeral, local ports, and related fixesStefano Brivio2021-04-291-4/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As we support UDP forwarding for packets that are sent to local ports, we actually need some kind of connection tracking for UDP. While at it, this commit introduces a number of vaguely related fixes for issues observed while trying this out. In detail: - implement an explicit, albeit minimalistic, connection tracking for UDP, to allow usage of ephemeral ports by the guest and by the host at the same time, by binding them dynamically as needed, and to allow mapping address changes for packets with a loopback address as destination - set the guest MAC address whenever we receive a packet from tap instead of waiting for an ARP request, and set it to broadcast on start, otherwise DHCPv6 might not work if all DHCPv6 requests time out before the guest starts talking IPv4 - split context IPv6 address into address we assign, global or site address seen on tap, and link-local address seen on tap, and make sure we use the addresses we've seen as destination (link-local choice depends on source address). Similarly, for IPv4, split into address we assign and address we observe, and use the address we observe as destination - introduce a clock_gettime() syscall right after epoll_wait() wakes up, so that we can remove all the other ones and pass the current timestamp to tap and socket handlers -- this is additionally needed by UDP to time out bindings to ephemeral ports and mappings between loopback address and a local address - rename sock_l4_add() to sock_l4(), no semantic changes intended - include <arpa/inet.h> in passt.c before kernel headers so that we can use <netinet/in.h> macros to check IPv6 address types, and remove a duplicate <linux/ip.h> inclusion Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* passt: Spare some syscalls, add some optimisations from profilingStefano Brivio2021-04-231-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Avoid a bunch of syscalls on forwarding paths by: - storing minimum and maximum file descriptor numbers for each protocol, fall back to SO_PROTOCOL query only on overlaps - allocating a larger receive buffer -- this can result in more coalesced packets than sendmmsg() can take (UIO_MAXIOV, i.e. 1024), so make sure we don't exceed that within a single call to protocol tap handlers - nesting the handling loop in tap_handler() in the receive loop, so that we have better chances of filling our receive buffer in fewer calls - skipping the recvfrom() in the UDP handler on EPOLLERR -- there's nothing to be done in that case and while at it: - restore the 20ms timer interval for periodic (TCP) events, I accidentally changed that to 100ms in an earlier commit - attempt using SO_ZEROCOPY for UDP -- if it's not available, sendmmsg() will succeed anyway - fix the handling of the status code from sendmmsg(), if it fails, we'll try to discard the first message, hence return 1 from the UDP handler Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* passt: Introduce packet batching mechanismStefano Brivio2021-04-221-11/+20
| | | | | | | | | | Receive packets in batches from AF_UNIX, check if they can be sent with a single syscall, and batch them up with sendmmsg() in case. A bit rudimentary, currently only implemented for UDP, but it seems to work. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* passt: Introduce ICMP echo proxyStefano Brivio2021-03-181-0/+136
It's nice to be able to confirm connectivity using ICMP or ICMPv6 echo requests, and "ping" sockets on Linux (IPPROTO_ICMP datagram) allow us to do that without any special capability. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-09 23:02:28 +0000