1/* Small standalone test program to check the existence of Capsicum syscalls */
2#include <sys/types.h>
3#include <sys/stat.h>
4#include <sys/wait.h>
5#include <fcntl.h>
6#include <unistd.h>
7#include <sys/syscall.h>
8#include <stdio.h>
9#include <string.h>
10#include <errno.h>
11#include <stdlib.h>
12#include <signal.h>
13
14#include "capsicum.h"
15
16#ifdef __linux__
17// glibc on Linux caches getpid() return value.
18int getpid_(void) { return syscall(__NR_getpid); }
19#else
20#define getpid_ getpid
21#endif
22
23static int seen_sigchld = 0;
24static void handle_signal(int x) {
25  fprintf(stderr, "[%d] received SIGCHLD\n", getpid_());
26  seen_sigchld = 1;
27}
28
29int main(int argc, char *argv[]) {
30  signal(SIGCHLD, handle_signal);
31  int lifetime = 4; /* seconds */
32  if (1 < argc) {
33    lifetime = atoi(argv[1]);
34  }
35
36  /* cap_rights_limit() available? */
37  cap_rights_t r_rws;
38  cap_rights_init(&r_rws, CAP_READ, CAP_WRITE, CAP_SEEK);
39  int cap_fd = dup(STDOUT_FILENO);
40  int rc = cap_rights_limit(cap_fd, &r_rws);
41  fprintf(stderr, "[%d] cap_fd=%d\n", getpid_(), cap_fd);
42  if (rc < 0) fprintf(stderr, "*** cap_rights_limit() failed: errno=%d %s\n", errno, strerror(errno));
43
44  /* cap_rights_get() available? */
45  cap_rights_t rights;
46  cap_rights_init(&rights, 0);
47  rc = cap_rights_get(cap_fd, &rights);
48  char buffer[256];
49  cap_rights_describe(&rights, buffer);
50  fprintf(stderr, "[%d] cap_rights_get(cap_fd=%d) rc=%d rights=%s\n", getpid_(), cap_fd, rc, buffer);
51  if (rc < 0) fprintf(stderr, "*** cap_rights_get() failed: errno=%d %s\n", errno, strerror(errno));
52
53  /* fstat() policed? */
54  struct stat buf;
55  rc = fstat(cap_fd, &buf);
56  fprintf(stderr, "[%d] fstat(cap_fd=%d) rc=%d errno=%d\n", getpid_(), cap_fd, rc, errno);
57  if (rc != -1) fprintf(stderr, "*** fstat() unexpectedly succeeded\n");
58
59  /* pdfork() available? */
60  int pd = -1;
61  rc = pdfork(&pd, 0);
62  if (rc < 0) fprintf(stderr, "*** pdfork() failed: errno=%d %s\n", errno, strerror(errno));
63
64  if (rc == 0) { /* child */
65    int count = 0;
66    while (count < 20) {
67      fprintf(stderr, "  [%d] child alive, parent is ppid=%d\n", getpid_(), getppid());
68      sleep(1);
69    }
70    fprintf(stderr, "  [%d] child exit(0)\n", getpid_());
71    exit(0);
72  }
73  fprintf(stderr, "[%d] pdfork() rc=%d pd=%d\n", getpid_(), rc, pd);
74
75  /* pdgetpid() available? */
76  pid_t actual_pid = rc;
77  pid_t got_pid = -1;
78  rc = pdgetpid(pd, &got_pid);
79  if (rc < 0) fprintf(stderr, "*** pdgetpid(pd=%d) failed: errno=%d %s\n", pd, errno, strerror(errno));
80  fprintf(stderr, "[%d] pdgetpid(pd=%d)=%d, pdfork returned %d\n", getpid_(), pd, got_pid, actual_pid);
81
82  sleep(lifetime);
83
84  /* pdkill() available? */
85  rc = pdkill(pd, SIGKILL);
86  fprintf(stderr, "[%d] pdkill(pd=%d, SIGKILL) -> rc=%d\n", getpid_(), pd, rc);
87  if (rc < 0) fprintf(stderr, "*** pdkill() failed: errno=%d %s\n", errno, strerror(errno));
88  usleep(50000);  /* Allow time for death and signals */
89
90  /* Death of a pdforked child should be invisible */
91  if (seen_sigchld) fprintf(stderr, "*** SIGCHLD emitted\n");
92  int status;
93  rc = wait4(-1, &status, WNOHANG, NULL);
94  if (rc > 0) fprintf(stderr, "*** wait4(-1, ...) unexpectedly found child %d\n", rc);
95
96  fprintf(stderr, "[%d] forking off a child process to check cap_enter()\n", getpid_());
97  pid_t child = fork();
98  if (child == 0) { /* child */
99    /* cap_getmode() / cap_enter() available? */
100    unsigned int cap_mode = -1;
101    rc = cap_getmode(&cap_mode);
102    fprintf(stderr, "  [%d] cap_getmode() -> rc=%d, cap_mode=%d\n", getpid_(), rc, cap_mode);
103    if (rc < 0) fprintf(stderr, "*** cap_getmode() failed: errno=%d %s\n", errno, strerror(errno));
104
105    rc = cap_enter();
106    fprintf(stderr, "  [%d] cap_enter() -> rc=%d\n", getpid_(), rc);
107    if (rc < 0) fprintf(stderr, "*** cap_enter() failed: errno=%d %s\n", errno, strerror(errno));
108
109    rc = cap_getmode(&cap_mode);
110    fprintf(stderr, "  [%d] cap_getmode() -> rc=%d, cap_mode=%d\n", getpid_(), rc, cap_mode);
111    if (rc < 0) fprintf(stderr, "*** cap_getmode() failed: errno=%d %s\n", errno, strerror(errno));
112
113    /* open disallowed? */
114    rc = open("/etc/passwd", O_RDONLY);
115    fprintf(stderr, "  [%d] open('/etc/passwd') -> rc=%d, errno=%d\n", getpid_(), rc, errno);
116    if (rc != -1) fprintf(stderr, "*** open() unexpectedly succeeded\n");
117#ifdef ECAPMODE
118    if (errno != ECAPMODE) fprintf(stderr, "*** open() failed with errno %d not ECAPMODE\n", errno);
119#endif
120    exit(0);
121  }
122  rc = wait4(child, &status, 0, NULL);
123  fprintf(stderr, "[%d] child %d exited with status %x\n", getpid_(), child, status);
124
125  /* fexecve() available? */
126  char* argv_pass[] = {(char*)"/bin/ls", "-l", "smoketest", NULL};
127  char* null_envp[] = {NULL};
128  int ls_bin = open("/bin/ls", O_RDONLY);
129  fprintf(stderr, "[%d] about to fexecve('/bin/ls', '-l', 'smoketest')\n", getpid_());
130  rc = fexecve(ls_bin, argv_pass, null_envp);
131  /* should never reach here */
132  fprintf(stderr, "*** fexecve(fd=%d) failed: rc=%d errno=%d %s\n", ls_bin, rc, errno, strerror(errno));
133
134  return 0;
135}
136