1 files changed, 146 insertions, 0 deletions
diff --git a/common.c b/common.c
new file mode 100644
index 0000000..b39fbd6
--- /dev/null
+++ b/common.c
@@ -0,0 +1,146 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+char *argv0;
+
+static pid_t image_decoder_pid;
+static pid_t image_encoder_pid;
+
+
+void
+eprintf(const char *fmt, ...)
+{
+	va_list ap;
+	va_start(ap, fmt);
+
+	if (argv0 && strncmp(fmt, "usage", strlen("usage")))
+		fprintf(stderr, "%s: ", argv0);
+
+	vfprintf(stderr, fmt, ap);
+
+	if (fmt[0] && fmt[strlen(fmt)-1] == ':') {
+		fputc(' ', stderr);
+		perror(NULL);
+	}
+
+	va_end(ap);
+	exit(1);
+}
+
+
+void
+bff_begin(void)
+{
+	int rw[2];
+
+	if (pipe(rw))
+		eprintf("pipe:");
+	switch (image_decoder_pid = fork()) {
+	case -1:
+		eprintf("fork:");
+		break;
+	case 0:
+		if (prctl(PR_SET_PDEATHSIG, SIGKILL))
+			eprintf("prctl PR_SET_PDEATHSIG SIGKILL:");
+		close(rw[0]);
+		if (dup2(rw[1], STDOUT_FILENO) < 0)
+			eprintf("dup2 <pipe> <stdout>:");
+		close(rw[1]);
+		execlp("blind-from-image", "blind-from-image", "-f", NULL);
+		eprintf("execlp blind-from-image:");
+		break;
+	default:
+		break;
+	}
+	close(rw[1]);
+	if (dup2(rw[0], STDIN_FILENO) < 0)
+		eprintf("dup2 <pipe> <stdin>:");
+	close(rw[0]);
+
+	if (pipe(rw))
+		eprintf("pipe:");
+	switch (image_encoder_pid = fork()) {
+	case -1:
+		eprintf("fork:");
+		break;
+	case 0:
+		if (prctl(PR_SET_PDEATHSIG, SIGKILL))
+			eprintf("prctl PR_SET_PDEATHSIG SIGKILL:");
+		close(rw[1]);
+		if (dup2(rw[0], STDIN_FILENO) < 0)
+			eprintf("dup2 <pipe> <stdin>:");
+		close(rw[0]);
+		execlp("blind-to-image", "blind-to-image", "-f", NULL);
+		eprintf("execlp blind-to-image:");
+		break;
+	default:
+		break;
+	}
+	close(rw[0]);
+	if (dup2(rw[1], STDOUT_FILENO) < 0)
+		eprintf("dup2 <pipe> <stdout>:");
+	close(rw[1]);
+}
+
+
+void
+bff_end(void)
+{
+	int status;
+
+	if (waitpid(image_decoder_pid, &status, 0) < 0)
+		eprintf("waitpid blind-from-image:");
+	if (status)
+		exit(1);
+
+	if (waitpid(image_encoder_pid, &status, 0) < 0)
+		eprintf("waitpid blind-to-image:");
+	if (status)
+		exit(1);
+}
+
+
+pid_t
+bff_run(const char **args, int in, int out)
+{
+	pid_t pid;
+
+	switch (pid = fork()) {
+	case -1:
+		eprintf("fork:");
+		break;
+	case 0:
+		if (prctl(PR_SET_PDEATHSIG, SIGKILL))
+			eprintf("prctl PR_SET_PDEATHSIG SIGKILL:");
+		if (in != STDIN_FILENO) {
+			if (dup2(in, STDIN_FILENO) < 0)
+				eprintf("dup2 <pipe> <stdin>:");
+			close(in);
+		}
+		if (out != STDOUT_FILENO) {
+			if (dup2(out, STDOUT_FILENO) < 0)
+				eprintf("dup2 <pipe> <stdout>:");
+			close(out);
+		}
+		execvp(*args, (void *)args);
+		eprintf("execlp %s:", *args);
+		break;
+	default:
+		break;
+	}
+	close(in);
+	close(out);
+
+	return pid;
+}
+
+
+void
+bff_wait(pid_t pid, const char *cmd)
+{
+	int status;
+	if (waitpid(pid, &status, 0) < 0)
+		eprintf("waitpid %s:", cmd);
+	if (status)
+		exit(1);
+}