Handle growing files better in qacp

Cache the results from the rstat packet and use that file size
during the following sendfile so we don't send more than qacp
is expecting.  This should allow us to qacp root@host:/var/log/messages

1 files changed, 19 insertions, 3 deletions

diff --git a/qarshd.c b/qarshd.c
index ccfd339..345f6de 100644
--- a/qarshd.c
+++ b/qarshd.c
@@ -51,6 +51,11 @@ int debug = 0;
 struct sockaddr_in peername;
 int child_exitted = 0;
 
+/* A mini cache for rstat so we can check it in pushfile */
+char *saved_path = NULL;
+struct stat saved_stat;
+
+
 int
 setup_user(char *user, char *group)
 {
@@ -196,22 +201,32 @@ pushfile(const char *path, int of_port)
 		return -1;
 	}
 
-	if (fstat(infd, &sb) < 0) {
+	if (strcmp(saved_path, path) == 0) {
+		nbytes = sendfile(outsd, infd, &offset, saved_stat.st_size);
+	} else if (fstat(infd, &sb) < 0) {
 		syslog(LOG_WARNING, "Could not stat %s: %s\n",
 		       path, strerror(errno));
 		close(infd);
 		close(outsd);
 		return -1;
+	} else { /* fstat filled in sb */
+		nbytes = sendfile(outsd, infd, &offset, sb.st_size);
 	}
 
-	nbytes = sendfile(outsd, infd, &offset, sb.st_size);
-
 	close(infd);
 	close(outsd);
 
 	return nbytes;
 }
 
+void
+save_stat(const char *path, const struct stat *sb)
+{
+	if (saved_path) free(saved_path);
+	saved_path = strdup(path);
+	memcpy(&saved_stat, sb, sizeof saved_stat);
+}
+
 struct qa_packet *
 rstat(const char *path)
 {
@@ -223,6 +238,7 @@ rstat(const char *path)
 	} else {
 		rp =  make_qp_rstat(path, &sb);
 	}
+	save_stat(path, &sb);
 
 	return rp;
 }