This patch adds instrumentation to allow modification of config of the terminal in virsh and successful reset of the state afterwards. The added helpers allow to disable receiving of SIGINT when pressing the key sequence (Ctrl+C usualy). This normally sends SIGINT to the foreground process group which kills ssh processes used for transport of the data. --- The termios code may need protecting with #ifndef WIN32. tools/virsh.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ tools/virsh.h | 9 +++++++++ 2 files changed, 63 insertions(+) diff --git a/tools/virsh.c b/tools/virsh.c index 38345c0..2f04e6a 100644 --- a/tools/virsh.c +++ b/tools/virsh.c @@ -2213,6 +2213,53 @@ vshPrintExtra(vshControl *ctl, const char *format, ...) } +bool +vshTTYIsInterruptCharacter(vshControl *ctl, + const char chr) +{ + if (ctl->istty && + ctl->termattr.c_cc[VINTR] == chr) + return true; + + return false; +} + + +int +vshTTYDisableInterrupt(vshControl *ctl) +{ + struct termios termset = ctl->termattr; + + if (!ctl->istty) + return -1; + + /* check if we need to set the terminal */ + if (termset.c_cc[VINTR] == _POSIX_VDISABLE) + return 0; + + termset.c_cc[VINTR] = _POSIX_VDISABLE; + termset.c_lflag &= ~ICANON; + + if (tcsetattr(STDIN_FILENO, TCSANOW, &termset) < 0) + return -1; + + return 0; +} + + +int +vshTTYRestore(vshControl *ctl) +{ + if (!ctl->istty) + return 0; + + if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &ctl->termattr) < 0) + return -1; + + return 0; +} + + void vshError(vshControl *ctl, const char *format, ...) { @@ -3157,6 +3204,13 @@ main(int argc, char **argv) return EXIT_FAILURE; } + if (isatty(STDIN_FILENO)) { + ctl->istty = true; + + if (tcgetattr(STDIN_FILENO, &ctl->termattr) < 0) + ctl->istty = false; + } + if (virMutexInit(&ctl->lock) < 0) { vshError(ctl, "%s", _("Failed to initialize mutex")); return EXIT_FAILURE; diff --git a/tools/virsh.h b/tools/virsh.h index 570d6a9..db5934f 100644 --- a/tools/virsh.h +++ b/tools/virsh.h @@ -32,6 +32,7 @@ # include <unistd.h> # include <sys/stat.h> # include <inttypes.h> +# include <termios.h> # include "internal.h" # include "virerror.h" @@ -240,6 +241,9 @@ struct _vshControl { const char *escapeChar; /* String representation of console escape character */ + + struct termios termattr; /* settings of the tty terminal */ + bool istty; /* is the terminal a tty */ }; struct _vshCmdGrp { @@ -350,6 +354,11 @@ void vshReportError(vshControl *ctl); void vshResetLibvirtError(void); void vshSaveLibvirtError(void); +/* terminal modifications */ +bool vshTTYIsInterruptCharacter(vshControl *ctl, const char chr); +int vshTTYDisableInterrupt(vshControl *ctl); +int vshTTYRestore(vshControl *ctl); + /* allocation wrappers */ void *_vshMalloc(vshControl *ctl, size_t sz, const char *filename, int line); # define vshMalloc(_ctl, _sz) _vshMalloc(_ctl, _sz, __FILE__, __LINE__) -- 1.8.3.2

The vshWatchJob function registers a SIGINT handler that is used to abort the active job and does not terminate virsh. Unfortunately, this breaks when using the ssh transport as SIGINT is sent to the foreground process group including the ssh transport processes which terminate. This breaks the connection and migration is left in a insane state. With this patch the terminal is modified to ignore key binding that sends SIGINT and does the handling manually. Resoves: https://bugzilla.redhat.com/show_bug.cgi?id=983348 --- tools/virsh-domain.c | 45 ++++++++++++++++++++++++++++++++------------- 1 file changed, 32 insertions(+), 13 deletions(-) diff --git a/tools/virsh-domain.c b/tools/virsh-domain.c index 3fd57fd..c87cf6a 100644 --- a/tools/virsh-domain.c +++ b/tools/virsh-domain.c @@ -3522,13 +3522,15 @@ vshWatchJob(vshControl *ctl, { struct sigaction sig_action; struct sigaction old_sig_action; - struct pollfd pollfd; + struct pollfd pollfd[2] = {{.fd = pipe_fd, .events = POLLIN, .revents = 0}, + {.fd = STDIN_FILENO, .events = POLLIN, .revents = 0}}; struct timeval start, curr; virDomainJobInfo jobinfo; int ret = -1; char retchar; bool functionReturn = false; sigset_t sigmask, oldsigmask; + bool jobStarted = false; sigemptyset(&sigmask); sigaddset(&sigmask, SIGINT); @@ -3539,16 +3541,21 @@ vshWatchJob(vshControl *ctl, sigemptyset(&sig_action.sa_mask); sigaction(SIGINT, &sig_action, &old_sig_action); - pollfd.fd = pipe_fd; - pollfd.events = POLLIN; - pollfd.revents = 0; - GETTIMEOFDAY(&start); while (1) { -repoll: - ret = poll(&pollfd, 1, 500); + ret = poll((struct pollfd *)&pollfd, 2, 500); if (ret > 0) { - if (pollfd.revents & POLLIN && + if (pollfd[1].revents & POLLIN && + saferead(STDIN_FILENO, &retchar, sizeof(retchar)) > 0) { + if (vshTTYIsInterruptCharacter(ctl, retchar)) { + virDomainAbortJob(dom); + goto cleanup; + } else { + continue; + } + } + + if (pollfd[0].revents & POLLIN && saferead(pipe_fd, &retchar, sizeof(retchar)) > 0 && retchar == '0') { if (verbose) { @@ -3566,7 +3573,7 @@ repoll: virDomainAbortJob(dom); intCaught = 0; } else { - goto repoll; + continue; } } goto cleanup; @@ -3583,13 +3590,24 @@ repoll: timeout = 0; } - if (verbose) { + if (verbose || !jobStarted) { pthread_sigmask(SIG_BLOCK, &sigmask, &oldsigmask); ret = virDomainGetJobInfo(dom, &jobinfo); pthread_sigmask(SIG_SETMASK, &oldsigmask, NULL); - if (ret == 0) - vshPrintJobProgress(label, jobinfo.dataRemaining, - jobinfo.dataTotal); + if (ret == 0) { + if (verbose) + vshPrintJobProgress(label, jobinfo.dataRemaining, + jobinfo.dataTotal); + + if (!jobStarted && + (jobinfo.type == VIR_DOMAIN_JOB_BOUNDED || + jobinfo.type == VIR_DOMAIN_JOB_UNBOUNDED)) { + vshTTYDisableInterrupt(ctl); + jobStarted = true; + } + } else { + vshResetLibvirtError(); + } } } @@ -3597,6 +3615,7 @@ repoll: cleanup: sigaction(SIGINT, &old_sig_action, NULL); + vshTTYRestore(ctl); return functionReturn; } -- 1.8.3.2