diff options
Diffstat (limited to 'src/libknot/control/control.c')
-rw-r--r-- | src/libknot/control/control.c | 561 |
1 files changed, 561 insertions, 0 deletions
diff --git a/src/libknot/control/control.c b/src/libknot/control/control.c new file mode 100644 index 0000000..af68cfe --- /dev/null +++ b/src/libknot/control/control.c @@ -0,0 +1,561 @@ +/* Copyright (C) 2018 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 <http://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/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 + +/*! Default socket operations timeout in milliseconds. */ +#define DEFAULT_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); + memset(ctx->data, 0, 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 = malloc(sizeof(*ctx)); + if (ctx == NULL) { + return NULL; + } + memset(ctx, 0, sizeof(*ctx)); + + 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); + + memset(ctx, 0, 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. + ctx->listen_sock = net_bound_socket(SOCK_STREAM, (struct sockaddr *)&addr, 0); + if (ctx->listen_sock < 0) { + return ctx->listen_sock; + } + + // Start listening. + if (listen(ctx->listen_sock, 1) != 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), (struct sockaddr *)&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, -1); + if (ret <= 0) { + return 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, (struct sockaddr *)&addr, NULL); + 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; +} |