projects / linux-seccomp.git / blame
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|---|---|---|
| 8befd5cc MG |
1 | .TH "seccomp_attr_set" 3 "21 August 2014" "paul@paul-moore.com" "libseccomp Documentation" |
| 2 | .\" ////////////////////////////////////////////////////////////////////////// | |
| 3 | .SH NAME | |
| 4 | .\" ////////////////////////////////////////////////////////////////////////// | |
| 5 | seccomp_attr_set, seccomp_attr_get \- Manage the seccomp filter attributes | |
| 6 | .\" ////////////////////////////////////////////////////////////////////////// | |
| 7 | .SH SYNOPSIS | |
| 8 | .\" ////////////////////////////////////////////////////////////////////////// | |
| 9 | .nf | |
| 10 | .B #include <seccomp.h> | |
| 11 | .sp | |
| 12 | .B typedef void * scmp_filter_ctx; | |
| 13 | .B enum scmp_filter_attr; | |
| 14 | .sp | |
| 15 | .BI "int seccomp_attr_set(scmp_filter_ctx " ctx "," | |
| 16 | .BI " enum scmp_filter_attr " attr ", uint32_t " value ");" | |
| 17 | .BI "int seccomp_attr_get(scmp_filter_ctx " ctx "," | |
| 18 | .BI " enum scmp_filter_attr " attr ", uint32_t *" value ");" | |
| 19 | .sp | |
| 20 | Link with \fI\-lseccomp\fP. | |
| 21 | .fi | |
| 22 | .\" ////////////////////////////////////////////////////////////////////////// | |
| 23 | .SH DESCRIPTION | |
| 24 | .\" ////////////////////////////////////////////////////////////////////////// | |
| 25 | .P | |
| 26 | The | |
| 27 | .BR seccomp_attr_set () | |
| 28 | function sets the different seccomp filter attributes while the | |
| 29 | .BR seccomp_attr_get () | |
| 30 | function fetches the filter attributes. The seccomp filter attributes are | |
| 31 | tunable values that affect how the library behaves when generating and loading | |
| 32 | the seccomp filter into the kernel. The attributes are reset to their default | |
| 33 | values whenever the filter is initialized or reset via | |
| 34 | .BR seccomp_filter_init (3) | |
| 35 | or | |
| 36 | .BR seccomp_filter_reset (3). | |
| 37 | .P | |
| 38 | The filter context | |
| 39 | .I ctx | |
| 40 | is the value returned by the call to | |
| 41 | .BR seccomp_init (3). | |
| 42 | .P | |
| 43 | Valid | |
| 44 | .I attr | |
| 45 | values are as follows: | |
| 46 | .TP | |
| 47 | .B SCMP_FLTATR_ACT_DEFAULT | |
| 48 | The default filter action as specified in the call to | |
| 49 | .BR seccomp_filter_init (3) | |
| 50 | or | |
| 51 | .BR seccomp_filter_reset (3). | |
| 52 | This attribute is read-only. | |
| 53 | .TP | |
| 54 | .B SCMP_FLTATR_ACT_BADARCH | |
| 55 | The filter action taken when the loaded filter does not match the architecture | |
| 56 | of the executing application. Defaults to the | |
| 57 | .B SCMP_ACT_KILL | |
| 58 | action. | |
| 59 | .TP | |
| 60 | .B SCMP_FLTATR_CTL_NNP | |
| 61 | A flag to specify if the NO_NEW_PRIVS functionality should be enabled before | |
| 62 | loading the seccomp filter into the kernel. If set to off ( | |
| 63 | .I value | |
| 64 | == 0) then loading the seccomp filter into the kernel will fail if CAP_SYS_ADMIN | |
| 65 | is not set. Defaults to on ( | |
| 66 | .I value | |
| 67 | == 1). | |
| 68 | .TP | |
| 69 | .B SCMP_FLTATR_CTL_TSYNC | |
| 70 | A flag to specify if the kernel should attempt to synchronize the filters | |
| 71 | across all threads on | |
| 72 | .BR seccomp_load (3). | |
| 73 | If the kernel is unable to synchronize all of the thread then the load | |
| 74 | operation will fail. This flag is only available on Linux Kernel 3.17 or | |
| 75 | greater; attempting to enable this flag on earlier kernels will result in an | |
| 76 | error being returned. Defaults to off ( | |
| 77 | .I value | |
| 78 | == 0). | |
| 79 | .\" ////////////////////////////////////////////////////////////////////////// | |
| 80 | .SH RETURN VALUE | |
| 81 | .\" ////////////////////////////////////////////////////////////////////////// | |
| 82 | Returns zero on success, negative errno values on failure. | |
| 83 | .\" ////////////////////////////////////////////////////////////////////////// | |
| 84 | .SH EXAMPLES | |
| 85 | .\" ////////////////////////////////////////////////////////////////////////// | |
| 86 | .nf | |
| 87 | #include <seccomp.h> | |
| 88 | ||
| 89 | int main(int argc, char *argv[]) | |
| 90 | { | |
| 91 | int rc = \-1; | |
| 92 | scmp_filter_ctx ctx; | |
| 93 | ||
| 94 | ctx = seccomp_init(SCMP_ACT_ALLOW); | |
| 95 | if (ctx == NULL) | |
| 96 | goto out; | |
| 97 | ||
| 98 | /* ... */ | |
| 99 | ||
| 100 | rc = seccomp_attr_set(ctx, SCMP_FLTATR_ACT_BADARCH, SCMP_ACT_TRAP); | |
| 101 | if (rc < 0) | |
| 102 | goto out; | |
| 103 | ||
| 104 | /* ... */ | |
| 105 | ||
| 106 | out: | |
| 107 | seccomp_release(ctx); | |
| 108 | return \-rc; | |
| 109 | } | |
| 110 | .fi | |
| 111 | .\" ////////////////////////////////////////////////////////////////////////// | |
| 112 | .SH NOTES | |
| 113 | .\" ////////////////////////////////////////////////////////////////////////// | |
| 114 | .P | |
| 115 | While the seccomp filter can be generated independent of the kernel, kernel | |
| 116 | support is required to load and enforce the seccomp filter generated by | |
| 117 | libseccomp. | |
| 118 | .P | |
| 119 | The libseccomp project site, with more information and the source code | |
| 120 | repository, can be found at https://github.com/seccomp/libseccomp. This tool, | |
| 121 | as well as the libseccomp library, is currently under development, please | |
| 122 | report any bugs at the project site or directly to the author. | |
| 123 | .\" ////////////////////////////////////////////////////////////////////////// | |
| 124 | .SH AUTHOR | |
| 125 | .\" ////////////////////////////////////////////////////////////////////////// | |
| 126 | Paul Moore <paul@paul-moore.com> | |
| 127 | .\" ////////////////////////////////////////////////////////////////////////// | |
| 128 | .SH SEE ALSO | |
| 129 | .\" ////////////////////////////////////////////////////////////////////////// | |
| 130 | .BR seccomp_init (3), | |
| 131 | .BR seccomp_reset (3), | |
| 132 | .BR seccomp_load (3) |