- (djm) Robustify EGD/PRNGd code in face of socket closures. Patch from

[openssh.git] / entropy.c

diff --git a/entropy.c b/entropy.c
index 82bb574d28014009d5df8d13023205b5028e17ce..836b08af3f9d04674aaefd907290af7f0a72f03e 100644 (file)
--- a/entropy.c
+++ b/entropy.c
@@ -71,7 +71,8 @@ int get_random_bytes(unsigned char *buf, int len)
        int fd;
        char msg[2];
        struct sockaddr_un addr;
-       int addr_len;
+       int addr_len, rval, errors;
+       struct sigaction nsa, osa;
 
        /* Sanity checks */
        if (sizeof(EGD_SOCKET) > sizeof(addr.sun_path))
@@ -84,17 +85,22 @@ int get_random_bytes(unsigned char *buf, int len)
        strlcpy(addr.sun_path, EGD_SOCKET, sizeof(addr.sun_path));
        addr_len = offsetof(struct sockaddr_un, sun_path) + sizeof(EGD_SOCKET);
 
+       memset(&nsa, 0, sizeof(nsa));
+       nsa.sa_handler = SIG_IGN;
+       (void) sigaction(SIGPIPE, &nsa, &osa);
+
+       errors = rval = 0;
+reopen:
        fd = socket(AF_UNIX, SOCK_STREAM, 0);
        if (fd == -1) {
                error("Couldn't create AF_UNIX socket: %s", strerror(errno));
-               return(0);
+               goto done;
        }
 
        if (connect(fd, (struct sockaddr*)&addr, addr_len) == -1) {
                error("Couldn't connect to EGD socket \"%s\": %s",
                        addr.sun_path, strerror(errno));
-               close(fd);
-               return(0);
+               goto done;
        }
 
        /* Send blocking read request to EGD */
@@ -102,22 +108,33 @@ int get_random_bytes(unsigned char *buf, int len)
        msg[1] = len;
 
        if (atomicio(write, fd, msg, sizeof(msg)) != sizeof(msg)) {
+               if (errno == EPIPE && errors < 10) {
+                       close(fd);
+                       errors++;
+                       goto reopen;
+               }
                error("Couldn't write to EGD socket \"%s\": %s",
                        EGD_SOCKET, strerror(errno));
-               close(fd);
-               return(0);
+               goto done;
        }
 
        if (atomicio(read, fd, buf, len) != len) {
+               if (errno == EPIPE && errors < 10) {
+                       close(fd);
+                       errors++;
+                       goto reopen;
+               }
                error("Couldn't read from EGD socket \"%s\": %s",
                        EGD_SOCKET, strerror(errno));
-               close(fd);
-               return(0);
+               goto done;
        }
 
-       close(fd);
-
-       return(1);
+       rval = 1;
+done:
+       (void) sigaction(SIGPIPE, &osa, NULL);
+       if (fd != -1)
+               close(fd);
+       return(rval);
 }
 #else /* !EGD_SOCKET */
 #ifdef RANDOM_POOL