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>
91 lines
1.8 KiB
C
91 lines
1.8 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <netinet/in.h>
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#include <linux/bpf.h>
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#include <bpf/bpf_helpers.h>
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char _license[] SEC("license") = "GPL";
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__s32 page_size = 0;
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SEC("cgroup/getsockopt")
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int _getsockopt_child(struct bpf_sockopt *ctx)
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{
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__u8 *optval_end = ctx->optval_end;
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__u8 *optval = ctx->optval;
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if (ctx->level != SOL_IP || ctx->optname != IP_TOS)
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goto out;
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if (optval + 1 > optval_end)
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return 0; /* EPERM, bounds check */
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if (optval[0] != 0x80)
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return 0; /* EPERM, unexpected optval from the kernel */
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ctx->retval = 0; /* Reset system call return value to zero */
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optval[0] = 0x90;
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ctx->optlen = 1;
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return 1;
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out:
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/* optval larger than PAGE_SIZE use kernel's buffer. */
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if (ctx->optlen > page_size)
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ctx->optlen = 0;
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return 1;
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}
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SEC("cgroup/getsockopt")
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int _getsockopt_parent(struct bpf_sockopt *ctx)
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{
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__u8 *optval_end = ctx->optval_end;
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__u8 *optval = ctx->optval;
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if (ctx->level != SOL_IP || ctx->optname != IP_TOS)
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goto out;
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if (optval + 1 > optval_end)
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return 0; /* EPERM, bounds check */
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if (optval[0] != 0x90)
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return 0; /* EPERM, unexpected optval from the kernel */
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ctx->retval = 0; /* Reset system call return value to zero */
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optval[0] = 0xA0;
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ctx->optlen = 1;
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return 1;
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out:
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/* optval larger than PAGE_SIZE use kernel's buffer. */
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if (ctx->optlen > page_size)
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ctx->optlen = 0;
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return 1;
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}
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SEC("cgroup/setsockopt")
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int _setsockopt(struct bpf_sockopt *ctx)
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{
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__u8 *optval_end = ctx->optval_end;
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__u8 *optval = ctx->optval;
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if (ctx->level != SOL_IP || ctx->optname != IP_TOS)
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goto out;
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if (optval + 1 > optval_end)
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return 0; /* EPERM, bounds check */
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optval[0] += 0x10;
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ctx->optlen = 1;
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return 1;
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out:
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/* optval larger than PAGE_SIZE use kernel's buffer. */
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if (ctx->optlen > page_size)
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ctx->optlen = 0;
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return 1;
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}
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