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-rw-r--r--src/libknot/control/control.c568
1 files changed, 568 insertions, 0 deletions
diff --git a/src/libknot/control/control.c b/src/libknot/control/control.c
new file mode 100644
index 0000000..8656057
--- /dev/null
+++ b/src/libknot/control/control.c
@@ -0,0 +1,568 @@
+/* Copyright (C) 2023 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+ 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 <https://www.gnu.org/licenses/>.
+ */
+
+#include <assert.h>
+#include <poll.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "libknot/control/control.h"
+#include "libknot/attribute.h"
+#include "libknot/error.h"
+#include "contrib/mempattern.h"
+#include "contrib/net.h"
+#include "contrib/sockaddr.h"
+#include "contrib/string.h"
+#include "contrib/ucw/mempool.h"
+#include "contrib/wire_ctx.h"
+
+/*! Size of the input and output buffers. */
+#ifndef CTL_BUFF_SIZE
+#define CTL_BUFF_SIZE (256 * 1024)
+#endif
+
+/*! Listen backlog size. */
+#define LISTEN_BACKLOG 5
+
+/*! Default socket operations timeout in milliseconds. */
+#define DEFAULT_TIMEOUT (30 * 1000)
+
+/*! Accept poll timeout in milliseconds. */
+#define ACCEPT_TIMEOUT (5 * 1000)
+
+/*! The first data item code. */
+#define DATA_CODE_OFFSET 16
+
+/*! Control context structure. */
+struct knot_ctl {
+ /*! Memory pool context. */
+ knot_mm_t mm;
+ /*! Network operations timeout. */
+ int timeout;
+ /*! Server listening socket. */
+ int listen_sock;
+ /*! Remote server/client socket. */
+ int sock;
+
+ /*! The latter read data. */
+ knot_ctl_data_t data;
+
+ /*! Write wire context. */
+ wire_ctx_t wire_out;
+ /*! Read wire context. */
+ wire_ctx_t wire_in;
+
+ /*! Write buffer. */
+ uint8_t buff_out[CTL_BUFF_SIZE];
+ /*! Read buffer. */
+ uint8_t buff_in[CTL_BUFF_SIZE];
+};
+
+static int type_to_code(knot_ctl_type_t type)
+{
+ switch (type) {
+ case KNOT_CTL_TYPE_END: return 0;
+ case KNOT_CTL_TYPE_DATA: return 1;
+ case KNOT_CTL_TYPE_EXTRA: return 2;
+ case KNOT_CTL_TYPE_BLOCK: return 3;
+ default: return -1;
+ }
+}
+
+static int code_to_type(uint8_t code)
+{
+ switch (code) {
+ case 0: return KNOT_CTL_TYPE_END;
+ case 1: return KNOT_CTL_TYPE_DATA;
+ case 2: return KNOT_CTL_TYPE_EXTRA;
+ case 3: return KNOT_CTL_TYPE_BLOCK;
+ default: return -1;
+ }
+}
+
+static bool is_data_type(knot_ctl_type_t type)
+{
+ switch (type) {
+ case KNOT_CTL_TYPE_DATA:
+ case KNOT_CTL_TYPE_EXTRA:
+ return true;
+ default:
+ return false;
+ }
+}
+
+static int idx_to_code(knot_ctl_idx_t idx)
+{
+ if (idx >= KNOT_CTL_IDX__COUNT) {
+ return -1;
+ }
+
+ return DATA_CODE_OFFSET + idx;
+}
+
+static int code_to_idx(uint8_t code)
+{
+ if (code < DATA_CODE_OFFSET ||
+ code >= DATA_CODE_OFFSET + KNOT_CTL_IDX__COUNT) {
+ return -1;
+ }
+
+ return code - DATA_CODE_OFFSET;
+}
+
+static void reset_buffers(knot_ctl_t *ctx)
+{
+ ctx->wire_out = wire_ctx_init(ctx->buff_out, CTL_BUFF_SIZE);
+ ctx->wire_in = wire_ctx_init(ctx->buff_in, 0);
+}
+
+static void clean_data(knot_ctl_t *ctx)
+{
+ mp_flush(ctx->mm.ctx);
+ memzero(ctx->data, sizeof(ctx->data));
+}
+
+static void close_sock(int *sock)
+{
+ if (*sock < 0) {
+ return;
+ }
+
+ close(*sock);
+ *sock = -1;
+}
+
+_public_
+knot_ctl_t* knot_ctl_alloc(void)
+{
+ knot_ctl_t *ctx = calloc(1, sizeof(*ctx));
+ if (ctx == NULL) {
+ return NULL;
+ }
+
+ mm_ctx_mempool(&ctx->mm, MM_DEFAULT_BLKSIZE);
+ ctx->timeout = DEFAULT_TIMEOUT;
+ ctx->listen_sock = -1;
+ ctx->sock = -1;
+
+ reset_buffers(ctx);
+
+ return ctx;
+}
+
+_public_
+void knot_ctl_free(knot_ctl_t *ctx)
+{
+ if (ctx == NULL) {
+ return;
+ }
+
+ close_sock(&ctx->listen_sock);
+ close_sock(&ctx->sock);
+
+ clean_data(ctx);
+
+ mp_delete(ctx->mm.ctx);
+
+ memzero(ctx, sizeof(*ctx));
+ free(ctx);
+}
+
+_public_
+void knot_ctl_set_timeout(knot_ctl_t *ctx, int timeout_ms)
+{
+ if (ctx == NULL) {
+ return;
+ }
+
+ ctx->timeout = (timeout_ms > 0) ? timeout_ms : -1;
+}
+
+_public_
+int knot_ctl_bind(knot_ctl_t *ctx, const char *path)
+{
+ if (ctx == NULL || path == NULL) {
+ return KNOT_EINVAL;
+ }
+
+ // Prepare socket address.
+ struct sockaddr_storage addr;
+ int ret = sockaddr_set(&addr, AF_UNIX, path, 0);
+ if (ret != KNOT_EOK) {
+ return ret;
+ }
+
+ // Bind the socket.
+ mode_t mode = S_IWUSR | S_IWGRP;
+ ctx->listen_sock = net_bound_socket(SOCK_STREAM, &addr, 0, mode);
+ if (ctx->listen_sock < 0) {
+ return ctx->listen_sock;
+ }
+
+ // Start listening.
+ if (listen(ctx->listen_sock, LISTEN_BACKLOG) != 0) {
+ close_sock(&ctx->listen_sock);
+ return knot_map_errno();
+ }
+
+ return KNOT_EOK;
+}
+
+_public_
+void knot_ctl_unbind(knot_ctl_t *ctx)
+{
+ if (ctx == NULL || ctx->listen_sock < 0) {
+ return;
+ }
+
+ // Remove the control socket file.
+ struct sockaddr_storage addr;
+ socklen_t addr_len = sizeof(addr);
+ if (getsockname(ctx->listen_sock, (struct sockaddr *)&addr, &addr_len) == 0) {
+ char addr_str[SOCKADDR_STRLEN] = { 0 };
+ if (sockaddr_tostr(addr_str, sizeof(addr_str), &addr) > 0) {
+ (void)unlink(addr_str);
+ }
+ }
+
+ // Close the listening socket.
+ close_sock(&ctx->listen_sock);
+}
+
+_public_
+int knot_ctl_accept(knot_ctl_t *ctx)
+{
+ if (ctx == NULL) {
+ return KNOT_EINVAL;
+ }
+
+ knot_ctl_close(ctx);
+
+ // Control interface.
+ struct pollfd pfd = { .fd = ctx->listen_sock, .events = POLLIN };
+ int ret = poll(&pfd, 1, ACCEPT_TIMEOUT);
+ if (ret <= 0) {
+ return (ret == 0) ? KNOT_ETIMEOUT : knot_map_errno();
+ }
+
+ int client = net_accept(ctx->listen_sock, NULL);
+ if (client < 0) {
+ return client;
+ }
+
+ ctx->sock = client;
+
+ reset_buffers(ctx);
+
+ return KNOT_EOK;
+}
+
+_public_
+int knot_ctl_connect(knot_ctl_t *ctx, const char *path)
+{
+ if (ctx == NULL || path == NULL) {
+ return KNOT_EINVAL;
+ }
+
+ // Prepare socket address.
+ struct sockaddr_storage addr;
+ int ret = sockaddr_set(&addr, AF_UNIX, path, 0);
+ if (ret != KNOT_EOK) {
+ return ret;
+ }
+
+ // Connect to socket.
+ ctx->sock = net_connected_socket(SOCK_STREAM, &addr, NULL, false);
+ if (ctx->sock < 0) {
+ return ctx->sock;
+ }
+
+ reset_buffers(ctx);
+
+ return KNOT_EOK;
+}
+
+_public_
+void knot_ctl_close(knot_ctl_t *ctx)
+{
+ if (ctx == NULL) {
+ return;
+ }
+
+ close_sock(&ctx->sock);
+}
+
+static int ensure_output(knot_ctl_t *ctx, uint16_t len)
+{
+ wire_ctx_t *w = &ctx->wire_out;
+
+ // Check for enough available room in the output buffer.
+ size_t available = wire_ctx_available(w);
+ if (available >= len) {
+ return KNOT_EOK;
+ }
+
+ // Flush the buffer.
+ int ret = net_stream_send(ctx->sock, w->wire, wire_ctx_offset(w),
+ ctx->timeout);
+ if (ret < 0) {
+ return ret;
+ }
+
+ *w = wire_ctx_init(w->wire, CTL_BUFF_SIZE);
+
+ return KNOT_EOK;
+}
+
+static int send_item(knot_ctl_t *ctx, uint8_t code, const char *data, bool flush)
+{
+ wire_ctx_t *w = &ctx->wire_out;
+
+ // Write the control block code.
+ int ret = ensure_output(ctx, sizeof(uint8_t));
+ if (ret != KNOT_EOK) {
+ return ret;
+ }
+ wire_ctx_write_u8(w, code);
+ if (w->error != KNOT_EOK) {
+ return w->error;
+ }
+
+ // Control block data is optional.
+ if (data != NULL) {
+ // Get the data length.
+ size_t data_len = strlen(data);
+ if (data_len > UINT16_MAX) {
+ return KNOT_ERANGE;
+ }
+
+ // Write the data length.
+ ret = ensure_output(ctx, sizeof(uint16_t));
+ if (ret != KNOT_EOK) {
+ return ret;
+ }
+ wire_ctx_write_u16(w, data_len);
+ if (w->error != KNOT_EOK) {
+ return w->error;
+ }
+
+ // Write the data.
+ ret = ensure_output(ctx, data_len);
+ if (ret != KNOT_EOK) {
+ return ret;
+ }
+ wire_ctx_write(w, (uint8_t *)data, data_len);
+ if (w->error != KNOT_EOK) {
+ return w->error;
+ }
+ }
+
+ // Send finalized buffer.
+ if (flush && wire_ctx_offset(w) > 0) {
+ ret = net_stream_send(ctx->sock, w->wire, wire_ctx_offset(w),
+ ctx->timeout);
+ if (ret < 0) {
+ return ret;
+ }
+
+ *w = wire_ctx_init(w->wire, CTL_BUFF_SIZE);
+ }
+
+ return KNOT_EOK;
+}
+
+_public_
+int knot_ctl_send(knot_ctl_t *ctx, knot_ctl_type_t type, knot_ctl_data_t *data)
+{
+ if (ctx == NULL) {
+ return KNOT_EINVAL;
+ }
+
+ // Get the type code.
+ int code = type_to_code(type);
+ if (code == -1) {
+ return KNOT_EINVAL;
+ }
+
+ // Send unit type.
+ int ret = send_item(ctx, code, NULL, !is_data_type(type));
+ if (ret != KNOT_EOK) {
+ return ret;
+ }
+
+ // Send unit data.
+ if (is_data_type(type) && data != NULL) {
+ // Send all non-empty data items.
+ for (knot_ctl_idx_t i = 0; i < KNOT_CTL_IDX__COUNT; i++) {
+ const char *value = (*data)[i];
+ if (value == NULL) {
+ continue;
+ }
+
+ ret = send_item(ctx, idx_to_code(i), value, false);
+ if (ret != KNOT_EOK) {
+ return ret;
+ }
+ }
+ }
+
+ return KNOT_EOK;
+}
+
+static int ensure_input(knot_ctl_t *ctx, uint16_t len)
+{
+ wire_ctx_t *w = &ctx->wire_in;
+
+ // Check for enough available room in the input buffer.
+ size_t available = wire_ctx_available(w);
+ if (available >= len) {
+ return KNOT_EOK;
+ }
+
+ // Move unprocessed data to the beginning of the buffer.
+ memmove(w->wire, w->wire + wire_ctx_offset(w), available);
+
+ // Receive enough data.
+ while (available < len) {
+ int ret = net_stream_recv(ctx->sock, w->wire + available,
+ CTL_BUFF_SIZE - available,
+ ctx->timeout);
+ if (ret < 0) {
+ return ret;
+ }
+ assert(ret > 0);
+ available += ret;
+ }
+
+ ctx->wire_in = wire_ctx_init(w->wire, available);
+
+ return KNOT_EOK;
+}
+
+static int receive_item_code(knot_ctl_t *ctx, uint8_t *code)
+{
+ wire_ctx_t *w = &ctx->wire_in;
+
+ // Read the type.
+ int ret = ensure_input(ctx, sizeof(uint8_t));
+ if (ret != KNOT_EOK) {
+ return ret;
+ }
+ *code = wire_ctx_read_u8(w);
+ if (w->error != KNOT_EOK) {
+ return w->error;
+ }
+
+ return KNOT_EOK;
+}
+
+static int receive_item_value(knot_ctl_t *ctx, char **value)
+{
+ wire_ctx_t *w = &ctx->wire_in;
+
+ // Read value length.
+ int ret = ensure_input(ctx, sizeof(uint16_t));
+ if (ret != KNOT_EOK) {
+ return ret;
+ }
+ uint16_t data_len = wire_ctx_read_u16(w);
+ if (w->error != KNOT_EOK) {
+ return w->error;
+ }
+
+ // Read the value.
+ ret = ensure_input(ctx, data_len);
+ if (ret != KNOT_EOK) {
+ return ret;
+ }
+ *value = mm_alloc(&ctx->mm, data_len + 1);
+ if (*value == NULL) {
+ return KNOT_ENOMEM;
+ }
+ wire_ctx_read(w, *value, data_len);
+ if (w->error != KNOT_EOK) {
+ return w->error;
+ }
+ (*value)[data_len] = '\0';
+
+ return KNOT_EOK;
+}
+
+_public_
+int knot_ctl_receive(knot_ctl_t *ctx, knot_ctl_type_t *type, knot_ctl_data_t *data)
+{
+ if (ctx == NULL || type == NULL) {
+ return KNOT_EINVAL;
+ }
+
+ wire_ctx_t *w = &ctx->wire_in;
+
+ // Reset output variables.
+ *type = KNOT_CTL_TYPE_END;
+ clean_data(ctx);
+
+ // Read data units until end of message.
+ bool have_type = false;
+ while (true) {
+ uint8_t code;
+ int ret = receive_item_code(ctx, &code);
+ if (ret != KNOT_EOK) {
+ return ret;
+ }
+
+ // Process unit type.
+ int current_type = code_to_type(code);
+ if (current_type != -1) {
+ if (have_type) {
+ // Revert parsed type.
+ wire_ctx_skip(w, -sizeof(uint8_t));
+ assert(w->error == KNOT_EOK);
+ break;
+ }
+
+ // Set the unit type.
+ *type = current_type;
+
+ if (is_data_type(current_type)) {
+ have_type = true;
+ continue;
+ } else {
+ break;
+ }
+ }
+
+ // Check for data item code.
+ int idx = code_to_idx(code);
+ if (idx == -1) {
+ return KNOT_EINVAL;
+ }
+
+ // Store the item data value.
+ ret = receive_item_value(ctx, (char **)&ctx->data[idx]);
+ if (ret != KNOT_EOK) {
+ return ret;
+ }
+ }
+
+ // Set the output data.
+ if (data != NULL) {
+ memcpy(*data, ctx->data, sizeof(*data));
+ }
+
+ return KNOT_EOK;
+}
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