Greg Kroah-Hartman
598cf27219
Link: https://lore.kernel.org/r/20260217200002.683975158@linuxfoundation.org Tested-by: Florian Fainelli <florian.fainelli@broadcom.com> Tested-by: Takeshi Ogasawara <takeshi.ogasawara@futuring-girl.com> Tested-by: Peter Schneider <pschneider1968@googlemail.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Salvatore Bonaccorso <carnil@debian.org> Tested-by: Brett A C Sheffield <bacs@librecast.net> Tested-by: Mark Brown <broonie@kernel.org> Tested-by: Luna Jernberg <droidbittin@gmail.com> Tested-by: Ronald Warsow <rwarsow@gmx.de> Tested-by: Justin M. Forbes <jforbes@fedoraproject.org> Tested-by: Ron Economos <re@w6rz.net> Tested-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
120 lines
3.0 KiB
C
120 lines
3.0 KiB
C
// SPDX-License-Identifier: GPL-2.0
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// Copyright (c) 2018 Facebook
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#include <linux/stddef.h>
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#include <linux/bpf.h>
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#include <sys/socket.h>
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#include <bpf/bpf_helpers.h>
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#include <bpf/bpf_endian.h>
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#include <bpf_sockopt_helpers.h>
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#define SRC_REWRITE_IP6_0 0
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#define SRC_REWRITE_IP6_1 0
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#define SRC_REWRITE_IP6_2 0
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#define SRC_REWRITE_IP6_3 6
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#define DST_REWRITE_IP6_0 0
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#define DST_REWRITE_IP6_1 0
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#define DST_REWRITE_IP6_2 0
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#define DST_REWRITE_IP6_3 1
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#define DST_REWRITE_IP6_V4_MAPPED_0 0
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#define DST_REWRITE_IP6_V4_MAPPED_1 0
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#define DST_REWRITE_IP6_V4_MAPPED_2 0x0000FFFF
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#define DST_REWRITE_IP6_V4_MAPPED_3 0xc0a80004 // 192.168.0.4
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#define DST_REWRITE_PORT6 6666
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SEC("cgroup/sendmsg6")
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int sendmsg_v6_prog(struct bpf_sock_addr *ctx)
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{
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if (ctx->type != SOCK_DGRAM)
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return 0;
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if (!get_set_sk_priority(ctx))
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return 0;
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/* Rewrite source. */
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if (ctx->msg_src_ip6[3] == bpf_htonl(1) ||
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ctx->msg_src_ip6[3] == bpf_htonl(0)) {
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ctx->msg_src_ip6[0] = bpf_htonl(SRC_REWRITE_IP6_0);
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ctx->msg_src_ip6[1] = bpf_htonl(SRC_REWRITE_IP6_1);
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ctx->msg_src_ip6[2] = bpf_htonl(SRC_REWRITE_IP6_2);
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ctx->msg_src_ip6[3] = bpf_htonl(SRC_REWRITE_IP6_3);
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} else {
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/* Unexpected source. Reject sendmsg. */
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return 0;
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}
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/* Rewrite destination. */
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if (ctx->user_ip6[0] == bpf_htonl(0xFACEB00C)) {
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ctx->user_ip6[0] = bpf_htonl(DST_REWRITE_IP6_0);
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ctx->user_ip6[1] = bpf_htonl(DST_REWRITE_IP6_1);
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ctx->user_ip6[2] = bpf_htonl(DST_REWRITE_IP6_2);
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ctx->user_ip6[3] = bpf_htonl(DST_REWRITE_IP6_3);
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ctx->user_port = bpf_htons(DST_REWRITE_PORT6);
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} else {
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/* Unexpected destination. Reject sendmsg. */
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return 0;
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}
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return 1;
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}
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SEC("cgroup/sendmsg6")
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int sendmsg_v6_v4mapped_prog(struct bpf_sock_addr *ctx)
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{
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/* Rewrite source. */
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ctx->msg_src_ip6[0] = bpf_htonl(SRC_REWRITE_IP6_0);
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ctx->msg_src_ip6[1] = bpf_htonl(SRC_REWRITE_IP6_1);
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ctx->msg_src_ip6[2] = bpf_htonl(SRC_REWRITE_IP6_2);
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ctx->msg_src_ip6[3] = bpf_htonl(SRC_REWRITE_IP6_3);
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/* Rewrite destination. */
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ctx->user_ip6[0] = bpf_htonl(DST_REWRITE_IP6_V4_MAPPED_0);
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ctx->user_ip6[1] = bpf_htonl(DST_REWRITE_IP6_V4_MAPPED_1);
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ctx->user_ip6[2] = bpf_htonl(DST_REWRITE_IP6_V4_MAPPED_2);
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ctx->user_ip6[3] = bpf_htonl(DST_REWRITE_IP6_V4_MAPPED_3);
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ctx->user_port = bpf_htons(DST_REWRITE_PORT6);
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return 1;
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}
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SEC("cgroup/sendmsg6")
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int sendmsg_v6_wildcard_prog(struct bpf_sock_addr *ctx)
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{
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/* Rewrite source. */
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ctx->msg_src_ip6[0] = bpf_htonl(SRC_REWRITE_IP6_0);
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ctx->msg_src_ip6[1] = bpf_htonl(SRC_REWRITE_IP6_1);
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ctx->msg_src_ip6[2] = bpf_htonl(SRC_REWRITE_IP6_2);
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ctx->msg_src_ip6[3] = bpf_htonl(SRC_REWRITE_IP6_3);
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/* Rewrite destination. */
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ctx->user_ip6[0] = bpf_htonl(0);
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ctx->user_ip6[1] = bpf_htonl(0);
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ctx->user_ip6[2] = bpf_htonl(0);
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ctx->user_ip6[3] = bpf_htonl(0);
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ctx->user_port = bpf_htons(DST_REWRITE_PORT6);
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return 1;
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}
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SEC("cgroup/sendmsg6")
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int sendmsg_v6_preserve_dst_prog(struct bpf_sock_addr *ctx)
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{
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return 1;
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}
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SEC("cgroup/sendmsg6")
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int sendmsg_v6_deny_prog(struct bpf_sock_addr *ctx)
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{
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return 0;
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}
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char _license[] SEC("license") = "GPL";
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