diff options
| -rw-r--r-- | fish/rc.c | 134 | ||||
| -rw-r--r-- | guestfish.pod | 7 | ||||
| -rwxr-xr-x | regressions/test-remote.sh | 12 |
3 files changed, 138 insertions, 15 deletions
@@ -27,6 +27,7 @@ #include <sys/types.h> #include <sys/un.h> #include <signal.h> +#include <sys/socket.h> #include <rpc/types.h> #include <rpc/xdr.h> @@ -49,6 +50,124 @@ create_sockpath (pid_t pid, char *sockpath, int len, struct sockaddr_un *addr) strcpy (addr->sun_path, sockpath); } +static const socklen_t controllen = CMSG_LEN (sizeof (int)); + +static void +receive_stdout (int s) +{ + static struct cmsghdr *cmptr = NULL, *h; + struct msghdr msg; + struct iovec iov[1]; + + /* Our 1 byte buffer */ + char buf[1]; + + if (NULL == cmptr) { + cmptr = malloc (controllen); + if (NULL == cmptr) { + perror ("malloc"); + exit (1); + } + } + + /* Don't specify a source */ + msg.msg_name = NULL; + msg.msg_namelen = 0; + + /* Initialise the msghdr to receive zero byte */ + iov[0].iov_base = buf; + iov[0].iov_len = 1; + msg.msg_iov = iov; + msg.msg_iovlen = 1; + + /* Initialise the control data */ + msg.msg_control = cmptr; + msg.msg_controllen = controllen; + + /* Read a message from the socket */ + ssize_t n = recvmsg (s, &msg, 0); + if (n < 0) { + perror ("recvmsg stdout fd"); + exit (1); + } + + h = CMSG_FIRSTHDR(&msg); + if (NULL == h) { + fprintf (stderr, "didn't receive a stdout file descriptor\n"); + } + + else { + /* Extract the transferred file descriptor from the control data */ + int fd = *(int *)CMSG_DATA (h); + + /* Duplicate the received file descriptor to stdout */ + dup2 (fd, STDOUT_FILENO); + close (fd); + } +} + +static void +send_stdout (int s) +{ + static struct cmsghdr *cmptr = NULL; + struct msghdr msg; + struct iovec iov[1]; + + /* Our 1 byte dummy buffer */ + char buf[1]; + + /* Don't specify a destination */ + msg.msg_name = NULL; + msg.msg_namelen = 0; + + /* Initialise the msghdr to send zero byte */ + iov[0].iov_base = buf; + iov[0].iov_len = 1; + msg.msg_iov = iov; + msg.msg_iovlen = 1; + + /* Initialize the zero byte */ + buf[0] = 0; + + /* Initialize the control data */ + if (NULL == cmptr) { + cmptr = malloc (controllen); + if (NULL == cmptr) { + perror ("malloc"); + exit (1); + } + } + cmptr->cmsg_level = SOL_SOCKET; + cmptr->cmsg_type = SCM_RIGHTS; + cmptr->cmsg_len = controllen; + + /* Add control header to the message */ + msg.msg_control = cmptr; + msg.msg_controllen = controllen; + + /* Add STDOUT to the control data */ + *(int *)CMSG_DATA (cmptr) = STDOUT_FILENO; + + if (sendmsg (s, &msg, 0) != 1) { + perror ("sendmsg stdout fd"); + exit (1); + } +} + +static void +close_stdout (void) +{ + int fd; + + fd = open ("/dev/null", O_WRONLY); + if (fd == -1) + perror ("/dev/null"); + else { + dup2 (fd, STDOUT_FILENO); + close (fd); + } +} + /* Remote control server. */ void rc_listen (void) @@ -56,7 +175,7 @@ rc_listen (void) char sockpath[128]; pid_t pid; struct sockaddr_un addr; - int sock, s, i, fd; + int sock, s, i; FILE *fp; XDR xdr, xdr2; guestfish_hello hello; @@ -111,13 +230,7 @@ rc_listen (void) /* Now close stdout and substitute /dev/null. This is necessary * so that eval `guestfish --listen` doesn't block forever. */ - fd = open ("/dev/null", O_WRONLY); - if (fd == -1) - perror ("/dev/null"); - else { - dup2 (fd, 1); - close (fd); - } + close_stdout(); /* Read commands and execute them. */ while (!quit) { @@ -125,6 +238,8 @@ rc_listen (void) if (s == -1) perror ("accept"); else { + receive_stdout(s); + fp = fdopen (s, "r+"); xdrstdio_create (&xdr, fp, XDR_DECODE); @@ -180,6 +295,7 @@ rc_listen (void) error: xdr_destroy (&xdr); /* NB. This doesn't close 'fp'. */ fclose (fp); /* Closes the underlying socket 's'. */ + close_stdout(); /* Re-close stdout */ } } @@ -227,6 +343,8 @@ rc_remote (int pid, const char *cmd, int argc, char *argv[], return -1; } + send_stdout(sock); + /* Send the greeting. */ fp = fdopen (sock, "r+"); xdrstdio_create (&xdr, fp, XDR_ENCODE); diff --git a/guestfish.pod b/guestfish.pod index 5427b23b..2e50873f 100644 --- a/guestfish.pod +++ b/guestfish.pod @@ -394,13 +394,6 @@ You can have several guestfish listener processes running using: guestfish --remote=$pid1 cmd guestfish --remote=$pid2 cmd -=head2 STANDARD OUTPUT DURING REMOTE CONTROL - -Because of limitations in the C<eval> statement, stdout from the -listener is currently redirected to C</dev/null>. - -Stderr is unchanged. - =head2 REMOTE CONTROL DETAILS Remote control happens over a Unix domain socket called diff --git a/regressions/test-remote.sh b/regressions/test-remote.sh index f3c14b4b..783dd6e8 100755 --- a/regressions/test-remote.sh +++ b/regressions/test-remote.sh @@ -29,6 +29,18 @@ eval `../fish/guestfish --listen` ../fish/guestfish --remote sfdiskM /dev/sda , ../fish/guestfish --remote mkfs ext2 /dev/sda1 ../fish/guestfish --remote mount /dev/sda1 / + +# Failure of the above commands will cause the guestfish listener to exit. +# Incorrect return from echo_daemon will not, so need to ensure the listener +# exits in any case, while still reporting an error. +error=0 +echo=$(../fish/guestfish --remote echo_daemon "This is a test") +if [ "$echo" != "This is a test" ]; then + error=1; +fi + ../fish/guestfish --remote exit rm -f test.img + +exit $error |