1 #include <cap-ng.h> 2 #include <err.h> 3 #include <linux/capability.h> 4 #include <stdbool.h> 5 #include <string.h> 6 #include <stdio.h> 7 #include <sys/prctl.h> 8 #include <sys/auxv.h> 9 10 #ifndef PR_CAP_AMBIENT 11 #define PR_CAP_AMBIENT 47 12 # define PR_CAP_AMBIENT_IS_SET 1 13 # define PR_CAP_AMBIENT_RAISE 2 14 # define PR_CAP_AMBIENT_LOWER 3 15 # define PR_CAP_AMBIENT_CLEAR_ALL 4 16 #endif 17 18 #if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 19) 19 # define HAVE_GETAUXVAL 20 #endif 21 22 static bool bool_arg(char **argv, int i) 23 { 24 if (!strcmp(argv[i], "0")) 25 return false; 26 else if (!strcmp(argv[i], "1")) 27 return true; 28 else 29 errx(1, "wrong argv[%d]", i); 30 } 31 32 int main(int argc, char **argv) 33 { 34 const char *atsec = ""; 35 36 /* 37 * Be careful just in case a setgid or setcapped copy of this 38 * helper gets out. 39 */ 40 41 if (argc != 5) 42 errx(1, "wrong argc"); 43 44 #ifdef HAVE_GETAUXVAL 45 if (getauxval(AT_SECURE)) 46 atsec = " (AT_SECURE is set)"; 47 else 48 atsec = " (AT_SECURE is not set)"; 49 #endif 50 51 capng_get_caps_process(); 52 53 if (capng_have_capability(CAPNG_EFFECTIVE, CAP_NET_BIND_SERVICE) != bool_arg(argv, 1)) { 54 printf("[FAIL]\tWrong effective state%s\n", atsec); 55 return 1; 56 } 57 if (capng_have_capability(CAPNG_PERMITTED, CAP_NET_BIND_SERVICE) != bool_arg(argv, 2)) { 58 printf("[FAIL]\tWrong permitted state%s\n", atsec); 59 return 1; 60 } 61 if (capng_have_capability(CAPNG_INHERITABLE, CAP_NET_BIND_SERVICE) != bool_arg(argv, 3)) { 62 printf("[FAIL]\tWrong inheritable state%s\n", atsec); 63 return 1; 64 } 65 66 if (prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_IS_SET, CAP_NET_BIND_SERVICE, 0, 0, 0) != bool_arg(argv, 4)) { 67 printf("[FAIL]\tWrong ambient state%s\n", atsec); 68 return 1; 69 } 70 71 printf("[OK]\tCapabilities after execve were correct\n"); 72 return 0; 73 } 74
