Adding upstream version 2:4.20.0+dfsg.upstream/2%4.20.0+dfsg

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 190 insertions, 0 deletions

diff --git a/ctdb/common/pkt_read.c b/ctdb/common/pkt_read.c
new file mode 100644
index 0000000..212ace5
--- /dev/null
+++ b/ctdb/common/pkt_read.c
@@ -0,0 +1,190 @@
+/*
+   Reading packets using fixed and dynamic buffer
+
+   Copyright (C) Amitay Isaacs 2015
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+/* This is similar to read_packet abstraction.  The main different is that
+ * tevent fd event is created only once.
+ */
+
+#include "replace.h"
+#include "system/network.h"
+
+#include <talloc.h>
+#include <tevent.h>
+
+#include "lib/util/tevent_unix.h"
+
+#include "pkt_read.h"
+
+/*
+ * Read a packet using fixed buffer
+ */
+
+struct pkt_read_state {
+	int fd;
+	uint8_t *buf;
+	size_t buflen;
+	size_t nread, total;
+	bool use_fixed;
+	ssize_t (*more)(uint8_t *buf, size_t buflen, void *private_data);
+	void *private_data;
+};
+
+struct tevent_req *pkt_read_send(TALLOC_CTX *mem_ctx,
+				 struct tevent_context *ev,
+				 int fd, size_t initial,
+				 uint8_t *buf, size_t buflen,
+				 ssize_t (*more)(uint8_t *buf,
+						 size_t buflen,
+						 void *private_data),
+				 void *private_data)
+{
+	struct tevent_req *req;
+	struct pkt_read_state *state;
+
+	req = tevent_req_create(mem_ctx, &state, struct pkt_read_state);
+	if (req == NULL) {
+		return NULL;
+	}
+
+	state->fd = fd;
+
+	if (buf == NULL || buflen == 0) {
+		state->use_fixed = false;
+		state->buf = talloc_array(state, uint8_t, initial);
+		if (state->buf == NULL) {
+			talloc_free(req);
+			return NULL;
+		}
+		state->buflen = initial;
+	} else {
+		state->use_fixed = true;
+		state->buf = buf;
+		state->buflen = buflen;
+	}
+
+	state->nread = 0;
+	state->total = initial;
+
+	state->more = more;
+	state->private_data = private_data;
+
+	return req;
+}
+
+void pkt_read_handler(struct tevent_context *ev, struct tevent_fd *fde,
+		      uint16_t flags, struct tevent_req *req)
+{
+	struct pkt_read_state *state = tevent_req_data(
+		req, struct pkt_read_state);
+	ssize_t nread, more;
+	uint8_t *tmp;
+
+	nread = read(state->fd, state->buf + state->nread,
+		     state->total - state->nread);
+	if ((nread == -1) && (errno == EINTR)) {
+		/* retry */
+		return;
+	}
+	if (nread == -1) {
+		tevent_req_error(req, errno);
+		return;
+	}
+	if (nread == 0) {
+		/* fd closed */
+		tevent_req_error(req, EPIPE);
+		return;
+	}
+
+	state->nread += nread;
+	if (state->nread < state->total) {
+		/* come back later */
+		return;
+	}
+
+	/* Check if "more" asks for more data */
+	if (state->more == NULL) {
+		tevent_req_done(req);
+		return;
+	}
+
+	more = state->more(state->buf, state->nread, state->private_data);
+	if (more == -1) {
+		/* invalid packet */
+		tevent_req_error(req, EIO);
+		return;
+	}
+	if (more == 0) {
+		tevent_req_done(req);
+		return;
+	}
+
+	if (state->total + more < state->total) {
+		/* int wrapped */
+		tevent_req_error(req, EMSGSIZE);
+		return;
+	}
+
+	if (state->total + more < state->buflen) {
+		/* continue using fixed buffer */
+		state->total += more;
+		return;
+	}
+
+	if (state->use_fixed) {
+		/* switch to dynamic buffer */
+		tmp = talloc_array(state, uint8_t, state->total + more);
+		if (tevent_req_nomem(tmp, req)) {
+			return;
+		}
+
+		memcpy(tmp, state->buf, state->total);
+		state->use_fixed = false;
+	} else {
+		tmp = talloc_realloc(state, state->buf, uint8_t,
+				     state->total + more);
+		if (tevent_req_nomem(tmp, req)) {
+			return;
+		}
+	}
+
+	state->buf = tmp;
+	state->buflen = state->total + more;
+	state->total += more;
+}
+
+ssize_t pkt_read_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
+		      uint8_t **pbuf, bool *free_buf, int *perrno)
+{
+	struct pkt_read_state *state = tevent_req_data(
+		req, struct pkt_read_state);
+
+	if (tevent_req_is_unix_error(req, perrno)) {
+		return -1;
+	}
+
+	if (state->use_fixed) {
+		*pbuf = state->buf;
+		*free_buf = false;
+	} else {
+		*pbuf = talloc_steal(mem_ctx, state->buf);
+		*free_buf = true;
+	}
+
+	return state->total;
+}