launchd/testing/missed-fds.c

   1 /*
   2  * <rdar://problem/4389914> 8G1153: Cannot SSH into machine despite Remote Login being checked
   3  */
   4
   5 #include <sys/types.h>
   6 #include <sys/time.h>
   7 #include <sys/event.h>
   8 #include <sys/socket.h>
   9 #include <netinet/in.h>
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <stdbool.h>
  13 #include <unistd.h>
  14 #include <fcntl.h>
  15 #include <string.h>
  16 #include <errno.h>
  17 #include <assert.h>
  18
  19 static void do_parent(int thefd);
  20 static void do_child(int thefd);
  21
  22 int main(void)
  23 {
  24         int sp[2];
  25         pid_t p;
  26
  27         assert(socketpair(AF_UNIX, SOCK_STREAM, 0, sp) != -1);
  28
  29         assert((p = fork()) != -1);
  30
  31         if (p == 0) {
  32                 assert(close(sp[0]) != -1);
  33                 do_child(sp[1]);
  34         } else {
  35                 assert(close(sp[1]) != -1);
  36                 do_parent(sp[0]);
  37         }
  38
  39         exit(EXIT_SUCCESS);
  40 }
  41
  42 static int
  43 alloc_random_fd(void)
  44 {
  45         struct sockaddr_in ina;
  46         int fd;
  47
  48         memset(&ina, 0, sizeof(ina));
  49         ina.sin_family = AF_INET;
  50         assert((fd = socket(PF_INET, SOCK_STREAM, 0)) != -1);
  51         assert(bind(fd, (struct sockaddr *)&ina, sizeof(ina)) != -1);
  52         assert(listen(fd, SOMAXCONN) != -1);
  53
  54         return fd;
  55 }
  56
  57 static int total_fds_sent = 0;
  58
  59 void
  60 send_fds(int thefd)
  61 {
  62         struct cmsghdr *cm = NULL;
  63         struct msghdr mh;
  64         struct iovec iov;
  65         size_t sentctrllen = 0;
  66         int fdcnt = (rand() % 223) + 1; /* 223 is prime */
  67         int r, i, fds[fdcnt];
  68
  69         memset(&mh, 0, sizeof(mh));
  70
  71         iov.iov_base = &fdcnt;
  72         iov.iov_len = sizeof(fdcnt);
  73         mh.msg_iov = &iov;
  74         mh.msg_iovlen = 1;
  75
  76         for (i = 0; i < fdcnt; i++) {
  77                 fds[i] = alloc_random_fd();
  78         }
  79
  80         sentctrllen = mh.msg_controllen = CMSG_SPACE(fdcnt * sizeof(int));
  81
  82         mh.msg_control = cm = alloca(mh.msg_controllen);
  83
  84         memset(cm, 0, mh.msg_controllen);
  85
  86         cm->cmsg_len = CMSG_LEN(fdcnt * sizeof(int));
  87         cm->cmsg_level = SOL_SOCKET;
  88         cm->cmsg_type = SCM_RIGHTS;
  89
  90         memcpy(CMSG_DATA(cm), fds, fdcnt * sizeof(int));
  91
  92         if (sendmsg(thefd, &mh, 0) == -1) {
  93                 fprintf(stderr, "Child: sendmsg(): %s\n", strerror(errno));
  94                 fprintf(stderr, "Child: Tried to send %d fds\n", fdcnt);
  95                 fprintf(stderr, "Child: Total FDs sent: %d\n", total_fds_sent);
  96                 sleep(1);
  97                 exit(EXIT_FAILURE);
  98         }
  99         total_fds_sent += fdcnt;
 100
 101         assert(sentctrllen == mh.msg_controllen);
 102
 103         r = read(thefd, &i, sizeof(i));
 104         assert(r != -1);
 105         assert(r != 0);
 106
 107         for (i = 0; i < fdcnt; i++) {
 108                 assert(close(fds[i]) != -1);
 109         }
 110 }
 111
 112 void
 113 do_child(int thefd)
 114 {
 115         for (;;) {
 116                 send_fds(thefd);
 117         }
 118 }
 119
 120 static int total_fds_received = 0;
 121
 122 static bool
 123 fetch_and_check_fds(int thefd)
 124 {
 125         struct cmsghdr *cm = alloca(4096);
 126         struct msghdr mh;
 127         struct iovec iov;
 128         int r, i, *fds, fdcnt = 0, sentfds;
 129
 130         memset(&mh, 0, sizeof(mh));
 131
 132         iov.iov_base = &fdcnt;
 133         iov.iov_len = sizeof(fdcnt);
 134         mh.msg_iov = &iov;
 135         mh.msg_iovlen = 1;
 136         mh.msg_control = cm;
 137         mh.msg_controllen = 4096;
 138
 139         r = recvmsg(thefd, &mh, 0);
 140         assert(r != -1);
 141         assert(r != 0);
 142         assert(!(mh.msg_flags & MSG_CTRUNC));
 143         assert(mh.msg_controllen > 0);
 144
 145         fds = (int *)CMSG_DATA(cm);
 146         sentfds = (mh.msg_controllen - sizeof(struct cmsghdr)) / sizeof(int);
 147
 148         if (sentfds != fdcnt) {
 149                 fprintf(stderr, "%d FDs sent, %d actually received.\n", fdcnt, sentfds);
 150                 return false;
 151         }
 152
 153         total_fds_received += fdcnt;
 154
 155         for (i = 0; i < fdcnt; i++) {
 156                 assert(close(fds[i]) != -1);
 157         }
 158
 159         r = write(thefd, &fdcnt, sizeof(fdcnt));
 160         assert(r != -1);
 161         assert(r != 0);
 162
 163         return true;
 164 }
 165
 166 void
 167 do_parent(int thefd)
 168 {
 169         struct kevent kev;
 170         int kq, iter = 0;
 171
 172         EV_SET(&kev, thefd, EVFILT_READ, EV_ADD, 0, 0, NULL);
 173
 174         assert((kq = kqueue()) != -1);
 175         assert(kevent(kq, &kev, 1, NULL, 0, NULL) != -1);
 176
 177         for (iter = 0; ; iter++) {
 178                 assert(kevent(kq, NULL, 0, &kev, 1, NULL) == 1);
 179                 assert(kev.filter == EVFILT_READ);
 180                 if (!fetch_and_check_fds(thefd))
 181                         break;
 182         }
 183
 184         fprintf(stderr, "After %d iterations and %d FDs received, bug 4389914 still exists!\n", iter, total_fds_received);
 185         exit(EXIT_FAILURE);
 186 }