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-rw-r--r--src/ctl.c261
1 files changed, 261 insertions, 0 deletions
diff --git a/src/ctl.c b/src/ctl.c
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+/* -*- mode: c; c-file-style: "openbsd" -*- */
+/*
+ * Copyright (c) 2008 Vincent Bernat <bernat@luffy.cx>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <string.h>
+
+#include "ctl.h"
+#include "marshal.h"
+#include "log.h"
+#include "compat/compat.h"
+
+/**
+ * Create a new listening Unix socket for control protocol.
+ *
+ * @param name The name of the Unix socket.
+ * @return The socket when successful, -1 otherwise.
+ */
+int
+ctl_create(const char *name)
+{
+ int s;
+ struct sockaddr_un su;
+ int rc;
+
+ log_debug("control", "create control socket %s", name);
+
+ if ((s = socket(PF_UNIX, SOCK_STREAM, 0)) == -1) return -1;
+ if (fcntl(s, F_SETFD, FD_CLOEXEC) == -1) {
+ close(s);
+ return -1;
+ }
+ su.sun_family = AF_UNIX;
+ strlcpy(su.sun_path, name, sizeof(su.sun_path));
+ if (bind(s, (struct sockaddr *)&su, sizeof(struct sockaddr_un)) == -1) {
+ rc = errno;
+ close(s);
+ errno = rc;
+ return -1;
+ }
+
+ log_debug("control", "listen to control socket %s", name);
+ if (listen(s, 5) == -1) {
+ rc = errno;
+ close(s);
+ errno = rc;
+ log_debug("control", "cannot listen to control socket %s", name);
+ return -1;
+ }
+ return s;
+}
+
+/**
+ * Connect to the control Unix socket.
+ *
+ * @param name The name of the Unix socket.
+ * @return The socket when successful, -1 otherwise.
+ */
+int
+ctl_connect(const char *name)
+{
+ int s;
+ struct sockaddr_un su;
+ int rc;
+
+ log_debug("control", "connect to control socket %s", name);
+
+ if ((s = socket(PF_UNIX, SOCK_STREAM, 0)) == -1) return -1;
+ su.sun_family = AF_UNIX;
+ strlcpy(su.sun_path, name, sizeof(su.sun_path));
+ if (connect(s, (struct sockaddr *)&su, sizeof(struct sockaddr_un)) == -1) {
+ rc = errno;
+ log_warn("control", "unable to connect to socket %s", name);
+ close(s);
+ errno = rc;
+ return -1;
+ }
+ return s;
+}
+
+/**
+ * Remove the control Unix socket.
+ *
+ * @param name The name of the Unix socket.
+ */
+void
+ctl_cleanup(const char *name)
+{
+ log_debug("control", "cleanup control socket");
+ if (unlink(name) == -1) log_warn("control", "unable to unlink %s", name);
+}
+
+/**
+ * Serialize and "send" a structure through the control protocol.
+ *
+ * This function does not really send the message but outputs it to a buffer.
+ *
+ * @param output_buffer A pointer to a buffer to which the message will be
+ * appended. Can be @c NULL. In this case, the buffer will
+ * be allocated.
+ * @param[in,out] output_len The length of the provided buffer. Will be updated
+ * with the new length
+ * @param type The type of message we want to send.
+ * @param t The structure to be serialized and sent.
+ * @param mi The appropriate marshal structure for serialization.
+ * @return -1 in case of failure, 0 in case of success.
+ *
+ * Make sure this function logic matches the server-side one: @c levent_ctl_recv().
+ */
+int
+ctl_msg_send_unserialized(uint8_t **output_buffer, size_t *output_len,
+ enum hmsg_type type, void *t, struct marshal_info *mi)
+{
+ ssize_t len = 0, newlen;
+ void *buffer = NULL;
+
+ log_debug("control", "send a message through control socket");
+ if (t) {
+ len = marshal_serialize_(mi, t, &buffer, 0, NULL, 0);
+ if (len <= 0) {
+ log_warnx("control", "unable to serialize data");
+ return -1;
+ }
+ }
+
+ newlen = len + sizeof(struct hmsg_header);
+
+ if (*output_buffer == NULL) {
+ *output_len = 0;
+ if ((*output_buffer = malloc(newlen)) == NULL) {
+ log_warn("control", "no memory available");
+ free(buffer);
+ return -1;
+ }
+ } else {
+ void *new = realloc(*output_buffer, *output_len + newlen);
+ if (new == NULL) {
+ log_warn("control", "no memory available");
+ free(buffer);
+ return -1;
+ }
+ *output_buffer = new;
+ }
+
+ struct hmsg_header hdr;
+ memset(&hdr, 0, sizeof(struct hmsg_header));
+ hdr.type = type;
+ hdr.len = len;
+ memcpy(*output_buffer + *output_len, &hdr, sizeof(struct hmsg_header));
+ if (t)
+ memcpy(*output_buffer + *output_len + sizeof(struct hmsg_header),
+ buffer, len);
+ *output_len += newlen;
+ free(buffer);
+ return 0;
+}
+
+/**
+ * "Receive" and unserialize a structure through the control protocol.
+ *
+ * Like @c ctl_msg_send_unserialized(), this function uses buffer to receive the
+ * incoming message.
+ *
+ * @param[in,out] input_buffer The buffer with the incoming message. Will be
+ * updated once the message has been unserialized to
+ * point to the remaining of the message or will be
+ * freed if all the buffer has been consumed. Can be
+ * @c NULL.
+ * @param[in,out] input_len The length of the provided buffer. Will be updated
+ * to the length of remaining data once the message
+ * has been unserialized.
+ * @param expected_type The expected message type.
+ * @param[out] t Will contain a pointer to the unserialized structure.
+ * Can be @c NULL if we don't want to store the
+ * answer.
+ * @param mi The appropriate marshal structure for unserialization.
+ *
+ * @return -1 in case of error, 0 in case of success and the number of bytes we
+ * request to complete unserialization.
+ *
+ * When requesting a notification, the input buffer is left untouched if we
+ * don't get one and we fail silently.
+ */
+size_t
+ctl_msg_recv_unserialized(uint8_t **input_buffer, size_t *input_len,
+ enum hmsg_type expected_type, void **t, struct marshal_info *mi)
+{
+ struct hmsg_header hdr;
+ int rc = -1;
+
+ if (*input_buffer == NULL || *input_len < sizeof(struct hmsg_header)) {
+ /* Not enough data. */
+ return sizeof(struct hmsg_header) - *input_len;
+ }
+
+ log_debug("control", "receive a message through control socket");
+ memcpy(&hdr, *input_buffer, sizeof(struct hmsg_header));
+ if (hdr.len > HMSG_MAX_SIZE) {
+ log_warnx("control", "message received is too large");
+ /* We discard the whole buffer */
+ free(*input_buffer);
+ *input_buffer = NULL;
+ *input_len = 0;
+ return -1;
+ }
+ if (*input_len < sizeof(struct hmsg_header) + hdr.len) {
+ /* Not enough data. */
+ return sizeof(struct hmsg_header) + hdr.len - *input_len;
+ }
+ if (hdr.type != expected_type) {
+ if (expected_type == NOTIFICATION) return -1;
+ log_warnx("control",
+ "incorrect received message type (expected: %d, received: %d)",
+ expected_type, hdr.type);
+ goto end;
+ }
+
+ if (t && !hdr.len) {
+ log_warnx("control", "no payload available in answer");
+ goto end;
+ }
+ if (t) {
+ /* We have data to unserialize. */
+ if (marshal_unserialize_(mi, *input_buffer + sizeof(struct hmsg_header),
+ hdr.len, t, NULL, 0, 0) <= 0) {
+ log_warnx("control", "unable to deserialize received data");
+ goto end;
+ }
+ }
+
+ rc = 0;
+end:
+ /* Discard input buffer */
+ *input_len -= sizeof(struct hmsg_header) + hdr.len;
+ if (*input_len == 0) {
+ free(*input_buffer);
+ *input_buffer = NULL;
+ } else
+ memmove(*input_buffer,
+ *input_buffer + sizeof(struct hmsg_header) + hdr.len, *input_len);
+ return rc;
+}
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