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* port_fwd: Simplify get_bound_ports_*() to port_fwd_scan_*()David Gibson2023-11-071-2/+3
| | | | | | | | | | | | | | | | | | | | get_bound_ports_*() now only use their context and ns parameters to determine which forwarding maps they're operating on. Each function needs the map they're actually updating, as well as the map for the other direction, to avoid creating forwarding loops. The UDP function also requires the corresponding TCP map, to implement the behaviour where we forward UDP ports of the same number as bound TCP ports for tools like iperf3. Passing those maps directly as parameters simplifies the code without making the callers life harder, because those already know the relevant maps. IMO, invoking these functions in terms of where they're looking for updated forwarding also makes more logical sense than in terms of where they're looking for bound ports. Given that new way of looking at the functions, also rename them to port_fwd_scan_*(). Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* port_fwd: Move port scanning /proc fds into struct port_fwdDavid Gibson2023-11-071-0/+4
| | | | | | | | | | | | | Currently we store /proc/net fds used to implement automatic port forwarding in the proc_net_{tcp,udp} fields of the main context structure. However, in fact each of those is associated with a particular direction of forwarding, and we already have struct port_fwd which collects all other information related to a particular direction of port forwarding. We can simplify things a bit by moving the /proc fds into struct port_fwd. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* port_fwd: Split TCP and UDP cases for get_bound_ports()David Gibson2023-11-071-1/+2
| | | | | | | | | | | | Currently get_bound_ports() takes a parameter to determine if it scans for UDP or TCP bound ports, but in fact there's almost nothing in common between those two paths. The parameter appears primarily to have been a convenience for when we needed to invoke this function via NS_CALL(). Now that we don't need that, split it into separate TCP and UDP versions. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* port_fwd: Move automatic port forwarding code to port_fwd.[ch]David Gibson2023-11-071-0/+3
| | | | | | | | | | | | | The implementation of scanning /proc files to do automatic port forwarding is a bit awkwardly split between procfs_scan_listen() in util.c, get_bound_ports() and related functions in conf.c and the initial setup code in conf(). Consolidate all of this into port_fwd.h, which already has some related definitions, and a new port_fwd.c. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
* 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>
* Fix widespread off-by-one error dealing with port numbersDavid Gibson2022-09-241-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | Port numbers (for both TCP and UDP) are 16-bit, and so fit exactly into a 'short'. USHRT_MAX is therefore the maximum port number and this is widely used in the code. Unfortunately, a lot of those places don't actually want the maximum port number (USHRT_MAX == 65535), they want the total number of ports (65536). This leads to a number of potentially nasty consequences: * We have buffer overruns on the port_fwd::delta array if we try to use port 65535 * We have similar potential overruns for the tcp_sock_* arrays * Interestingly udp_act had the correct size, but we can calculate it in a more direct manner * We have a logical overrun of the ports bitmap as well, although it will just use an unused bit in the last byte so isnt harmful * Many loops don't consider port 65535 (which does mitigate some but not all of the buffer overruns above) * In udp_invert_portmap() we incorrectly compute the reverse port translation for return packets Correct all these by using a new NUM_PORTS defined explicitly for this purpose. Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
* Consolidate port forwarding configuration into a common structureDavid Gibson2022-09-241-0/+12
| | | | | | | | | | | | | | | The configuration for how to forward ports in and out of the guest/ns is divided between several different variables. For each connect direction and protocol we have a mode in the udp/tcp context structure, a bitmap of which ports to forward also in the context structure and an array of deltas to apply if the outward facing and inward facing port numbers are different. This last is a separate global variable, rather than being in the context structure, for no particular reason. UDP also requires an additional array which has the reverse mapping used for return packets. Consolidate these into a re-used substructure in the context structure. Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
* Improve types and names for port forwarding configurationDavid Gibson2022-09-241-0/+19
enum conf_port_type is local to conf.c and is used to track the port forwarding mode during configuration. We don't keep it around in the context structure, however the 'init_detect_ports' and 'ns_detect_ports' fields in the context are based solely on this. Rather than changing encoding, just include the forwarding mode into the context structure. Move the type definition to a new port_fwd.h, which is kind of trivial at the moment but will have more stuff later. While we're there, "conf_port_type" doesn't really convey that this enum is describing how port forwarding is configured. Rename it to port_fwd_mode. The variables (now fields) of this type also have mildly confusing names since it's not immediately obvious whether 'ns' and 'init' refer to the source or destination of the packets. Use "in" (host to guest / init to ns) and "out" (guest to host / ns to init) instead. This has the added bonus that we no longer have locals 'udp_init' and 'tcp_init' which shadow global functions. In addition, add a typedef 'port_fwd_map' for a bitmap of each port number, which is used in several places. Signed-off-by: David Gibson <david@gibson.dropbear.id.au>