/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com * * This program is free software; you can redistribute it and/or * modify it under the terms of version 2 of the GNU General Public * License as published by the Free Software Foundation. */ #include #include #include #include #include "bpf_helpers.h" struct bpf_map_def SEC("maps") my_map = { .type = BPF_MAP_TYPE_HASH, .key_size = sizeof(long), .value_size = sizeof(long), .max_entries = 1024, }; /* kprobe is NOT a stable ABI. If kernel internals change this bpf+kprobe * example will no longer be meaningful */ SEC("kprobe/kfree_skb") int bpf_prog2(struct pt_regs *ctx) { long loc = 0; long init_val = 1; long *value; /* read ip of kfree_skb caller. * non-portable version of __builtin_return_address(0) */ BPF_KPROBE_READ_RET_IP(loc, ctx); value = bpf_map_lookup_elem(&my_map, &loc); if (value) *value += 1; else bpf_map_update_elem(&my_map, &loc, &init_val, BPF_ANY); return 0; } static unsigned int log2(unsigned int v) { unsigned int r; unsigned int shift; r = (v > 0xFFFF) << 4; v >>= r; shift = (v > 0xFF) << 3; v >>= shift; r |= shift; shift = (v > 0xF) << 2; v >>= shift; r |= shift; shift = (v > 0x3) << 1; v >>= shift; r |= shift; r |= (v >> 1); return r; } static unsigned int log2l(unsigned long v) { unsigned int hi = v >> 32; if (hi) return log2(hi) + 32; else return log2(v); } struct hist_key { char comm[16]; u64 pid_tgid; u64 uid_gid; u64 index; }; struct bpf_map_def SEC("maps") my_hist_map = { .type = BPF_MAP_TYPE_PERCPU_HASH, .key_size = sizeof(struct hist_key), .value_size = sizeof(long), .max_entries = 1024, }; SEC("kprobe/sys_write") int bpf_prog3(struct pt_regs *ctx) { long write_size = PT_REGS_PARM3(ctx); long init_val = 1; long *value; struct hist_key key; key.index = log2l(write_size); key.pid_tgid = bpf_get_current_pid_tgid(); key.uid_gid = bpf_get_current_uid_gid(); bpf_get_current_comm(&key.comm, sizeof(key.comm)); value = bpf_map_lookup_elem(&my_hist_map, &key); if (value) __sync_fetch_and_add(value, 1); else bpf_map_update_elem(&my_hist_map, &key, &init_val, BPF_ANY); return 0; } char _license[] SEC("license") = "GPL"; u32 _version SEC("version") = LINUX_VERSION_CODE; xt' type='search' size='10' name='q' value=''/>

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