| .. | .. |
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| 1 | 1 | // SPDX-License-Identifier: GPL-2.0 |
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| 2 | 2 | /* |
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| 3 | | - * Augment the openat syscall with the contents of the filename pointer argument. |
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| 3 | + * Augment syscalls with the contents of the pointer arguments. |
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| 4 | 4 | * |
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| 5 | 5 | * Test it with: |
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| 6 | 6 | * |
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| .. | .. |
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| 10 | 10 | * the last one should be the one for '/etc/passwd'. |
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| 11 | 11 | * |
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| 12 | 12 | * This matches what is marshalled into the raw_syscall:sys_enter payload |
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| 13 | | - * expected by the 'perf trace' beautifiers, and can be used by them unmodified, |
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| 14 | | - * which will be done as that feature is implemented in the next csets, for now |
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| 15 | | - * it will appear in a dump done by the default tracepoint handler in 'perf trace', |
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| 16 | | - * that uses bpf_output__fprintf() to just dump those contents, as done with |
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| 17 | | - * the bpf-output event associated with the __bpf_output__ map declared in |
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| 18 | | - * tools/perf/include/bpf/stdio.h. |
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| 13 | + * expected by the 'perf trace' beautifiers, and can be used by them, that will |
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| 14 | + * check if perf_sample->raw_data is more than what is expected for each |
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| 15 | + * syscalls:sys_{enter,exit}_SYSCALL tracepoint, uing the extra data as the |
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| 16 | + * contents of pointer arguments. |
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| 19 | 17 | */ |
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| 20 | 18 | |
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| 21 | 19 | #include <stdio.h> |
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| 20 | +#include <linux/socket.h> |
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| 22 | 21 | |
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| 23 | | -struct bpf_map SEC("maps") __augmented_syscalls__ = { |
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| 24 | | - .type = BPF_MAP_TYPE_PERF_EVENT_ARRAY, |
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| 25 | | - .key_size = sizeof(int), |
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| 26 | | - .value_size = sizeof(u32), |
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| 27 | | - .max_entries = __NR_CPUS__, |
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| 22 | +/* bpf-output associated map */ |
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| 23 | +bpf_map(__augmented_syscalls__, PERF_EVENT_ARRAY, int, u32, __NR_CPUS__); |
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| 24 | + |
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| 25 | +struct syscall_exit_args { |
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| 26 | + unsigned long long common_tp_fields; |
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| 27 | + long syscall_nr; |
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| 28 | + long ret; |
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| 28 | 29 | }; |
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| 30 | + |
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| 31 | +struct augmented_filename { |
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| 32 | + unsigned int size; |
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| 33 | + int reserved; |
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| 34 | + char value[256]; |
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| 35 | +}; |
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| 36 | + |
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| 37 | +#define augmented_filename_syscall(syscall) \ |
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| 38 | +struct augmented_enter_##syscall##_args { \ |
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| 39 | + struct syscall_enter_##syscall##_args args; \ |
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| 40 | + struct augmented_filename filename; \ |
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| 41 | +}; \ |
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| 42 | +int syscall_enter(syscall)(struct syscall_enter_##syscall##_args *args) \ |
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| 43 | +{ \ |
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| 44 | + struct augmented_enter_##syscall##_args augmented_args = { .filename.reserved = 0, }; \ |
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| 45 | + unsigned int len = sizeof(augmented_args); \ |
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| 46 | + probe_read(&augmented_args.args, sizeof(augmented_args.args), args); \ |
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| 47 | + augmented_args.filename.size = probe_read_str(&augmented_args.filename.value, \ |
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| 48 | + sizeof(augmented_args.filename.value), \ |
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| 49 | + args->filename_ptr); \ |
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| 50 | + if (augmented_args.filename.size < sizeof(augmented_args.filename.value)) { \ |
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| 51 | + len -= sizeof(augmented_args.filename.value) - augmented_args.filename.size; \ |
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| 52 | + len &= sizeof(augmented_args.filename.value) - 1; \ |
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| 53 | + } \ |
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| 54 | + /* If perf_event_output fails, return non-zero so that it gets recorded unaugmented */ \ |
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| 55 | + return perf_event_output(args, &__augmented_syscalls__, BPF_F_CURRENT_CPU, \ |
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| 56 | + &augmented_args, len); \ |
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| 57 | +} \ |
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| 58 | +int syscall_exit(syscall)(struct syscall_exit_args *args) \ |
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| 59 | +{ \ |
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| 60 | + return 1; /* 0 as soon as we start copying data returned by the kernel, e.g. 'read' */ \ |
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| 61 | +} |
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| 29 | 62 | |
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| 30 | 63 | struct syscall_enter_openat_args { |
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| 31 | 64 | unsigned long long common_tp_fields; |
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| .. | .. |
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| 36 | 69 | long mode; |
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| 37 | 70 | }; |
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| 38 | 71 | |
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| 39 | | -struct augmented_enter_openat_args { |
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| 40 | | - struct syscall_enter_openat_args args; |
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| 41 | | - char filename[64]; |
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| 72 | +augmented_filename_syscall(openat); |
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| 73 | + |
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| 74 | +struct syscall_enter_open_args { |
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| 75 | + unsigned long long common_tp_fields; |
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| 76 | + long syscall_nr; |
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| 77 | + char *filename_ptr; |
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| 78 | + long flags; |
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| 79 | + long mode; |
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| 42 | 80 | }; |
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| 43 | 81 | |
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| 44 | | -int syscall_enter(openat)(struct syscall_enter_openat_args *args) |
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| 45 | | -{ |
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| 46 | | - struct augmented_enter_openat_args augmented_args; |
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| 82 | +augmented_filename_syscall(open); |
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| 47 | 83 | |
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| 48 | | - probe_read(&augmented_args.args, sizeof(augmented_args.args), args); |
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| 49 | | - probe_read_str(&augmented_args.filename, sizeof(augmented_args.filename), args->filename_ptr); |
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| 50 | | - perf_event_output(args, &__augmented_syscalls__, BPF_F_CURRENT_CPU, |
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| 51 | | - &augmented_args, sizeof(augmented_args)); |
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| 52 | | - return 1; |
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| 84 | +struct syscall_enter_inotify_add_watch_args { |
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| 85 | + unsigned long long common_tp_fields; |
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| 86 | + long syscall_nr; |
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| 87 | + long fd; |
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| 88 | + char *filename_ptr; |
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| 89 | + long mask; |
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| 90 | +}; |
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| 91 | + |
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| 92 | +augmented_filename_syscall(inotify_add_watch); |
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| 93 | + |
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| 94 | +struct statbuf; |
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| 95 | + |
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| 96 | +struct syscall_enter_newstat_args { |
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| 97 | + unsigned long long common_tp_fields; |
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| 98 | + long syscall_nr; |
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| 99 | + char *filename_ptr; |
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| 100 | + struct stat *statbuf; |
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| 101 | +}; |
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| 102 | + |
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| 103 | +augmented_filename_syscall(newstat); |
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| 104 | + |
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| 105 | +#ifndef _K_SS_MAXSIZE |
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| 106 | +#define _K_SS_MAXSIZE 128 |
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| 107 | +#endif |
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| 108 | + |
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| 109 | +#define augmented_sockaddr_syscall(syscall) \ |
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| 110 | +struct augmented_enter_##syscall##_args { \ |
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| 111 | + struct syscall_enter_##syscall##_args args; \ |
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| 112 | + struct sockaddr_storage addr; \ |
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| 113 | +}; \ |
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| 114 | +int syscall_enter(syscall)(struct syscall_enter_##syscall##_args *args) \ |
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| 115 | +{ \ |
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| 116 | + struct augmented_enter_##syscall##_args augmented_args; \ |
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| 117 | + unsigned long addrlen = sizeof(augmented_args.addr); \ |
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| 118 | + probe_read(&augmented_args.args, sizeof(augmented_args.args), args); \ |
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| 119 | +/* FIXME_CLANG_OPTIMIZATION_THAT_ACCESSES_USER_CONTROLLED_ADDRLEN_DESPITE_THIS_CHECK */ \ |
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| 120 | +/* if (addrlen > augmented_args.args.addrlen) */ \ |
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| 121 | +/* addrlen = augmented_args.args.addrlen; */ \ |
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| 122 | +/* */ \ |
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| 123 | + probe_read(&augmented_args.addr, addrlen, args->addr_ptr); \ |
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| 124 | + /* If perf_event_output fails, return non-zero so that it gets recorded unaugmented */ \ |
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| 125 | + return perf_event_output(args, &__augmented_syscalls__, BPF_F_CURRENT_CPU, \ |
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| 126 | + &augmented_args, \ |
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| 127 | + sizeof(augmented_args) - sizeof(augmented_args.addr) + addrlen);\ |
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| 128 | +} \ |
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| 129 | +int syscall_exit(syscall)(struct syscall_exit_args *args) \ |
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| 130 | +{ \ |
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| 131 | + return 1; /* 0 as soon as we start copying data returned by the kernel, e.g. 'read' */ \ |
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| 53 | 132 | } |
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| 54 | 133 | |
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| 134 | +struct sockaddr; |
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| 135 | + |
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| 136 | +struct syscall_enter_bind_args { |
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| 137 | + unsigned long long common_tp_fields; |
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| 138 | + long syscall_nr; |
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| 139 | + long fd; |
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| 140 | + struct sockaddr *addr_ptr; |
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| 141 | + unsigned long addrlen; |
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| 142 | +}; |
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| 143 | + |
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| 144 | +augmented_sockaddr_syscall(bind); |
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| 145 | + |
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| 146 | +struct syscall_enter_connect_args { |
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| 147 | + unsigned long long common_tp_fields; |
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| 148 | + long syscall_nr; |
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| 149 | + long fd; |
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| 150 | + struct sockaddr *addr_ptr; |
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| 151 | + unsigned long addrlen; |
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| 152 | +}; |
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| 153 | + |
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| 154 | +augmented_sockaddr_syscall(connect); |
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| 155 | + |
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| 156 | +struct syscall_enter_sendto_args { |
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| 157 | + unsigned long long common_tp_fields; |
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| 158 | + long syscall_nr; |
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| 159 | + long fd; |
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| 160 | + void *buff; |
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| 161 | + long len; |
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| 162 | + unsigned long flags; |
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| 163 | + struct sockaddr *addr_ptr; |
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| 164 | + long addr_len; |
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| 165 | +}; |
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| 166 | + |
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| 167 | +augmented_sockaddr_syscall(sendto); |
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| 168 | + |
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| 55 | 169 | license(GPL); |
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