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Diffstat (limited to '')
| -rw-r--r-- | src/communication.h | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/src/communication.h b/src/communication.h new file mode 100644 index 0000000..43af314 --- /dev/null +++ b/src/communication.h @@ -0,0 +1,137 @@ +/** + * coopgammad -- Cooperative gamma server + * Copyright (C) 2016 Mattias Andrée (maandree@kth.se) + * + * 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/>. + */ +#ifndef COMMUNICATION_H +#define COMMUNICATION_H + + +#include <stdio.h> +#include <stdlib.h> + + + +#ifndef GCC_ONLY +# if defined(__GNUC__) && !defined(__clang__) +# define GCC_ONLY(...) __VA_ARGS__ +# else +# define GCC_ONLY(...) /* nothing */ +# endif +#endif + + + +/** + * Construct a message + * + * @param bufp:char** Output parameter for the buffer, must not have side-effects + * @param np:size_t* Output parameter for the size of the buffer sans `extra` + * @param extra:size_t The extra number for bytes to allocate to the buffer + * @param format:string-literal Message format string + * @param ... Message formatting arguments + */ +#define MAKE_MESSAGE(bufp, np, extra, format, ...) \ + do \ + { \ + ssize_t m__; \ + snprintf(NULL, 0, format "%zn", __VA_ARGS__, &m__); \ + *(bufp) = malloc((size_t)(extra) + (size_t)m__); \ + if (*(bufp) == NULL) \ + return -1; \ + sprintf(*(bufp), format, __VA_ARGS__); \ + *(np) = (size_t)m__; \ + } \ + while (0) + +/** + * Send a custom error without an error number + * + * @param ... The error description to send + * @return 1: Client disconnected + * 0: Success (possibily delayed) + * -1: An error occurred + */ +#define send_error(...) ((send_error)(conn, message_id, __VA_ARGS__)) + +/** + * Send a standard error + * + * @param ... The value of `errno`, 0 to indicate success + * @return 1: Client disconnected + * 0: Success (possibily delayed) + * -1: An error occurred + */ +#define send_errno(...) ((send_errno)(conn, message_id, __VA_ARGS__)) + + + +/** + * Send a message + * + * @param conn The index of the connection + * @param buf The data to send + * @param n The size of `buf` + * @return Zero on success, -1 on error, 1 if disconncted + * EINTR, EAGAIN, EWOULDBLOCK, and ECONNRESET count + * as success (ECONNRESET cause 1 to be returned), + * and are handled appropriately. + */ +int send_message(size_t conn, char* restrict buf, size_t n); + +/** + * Send a custom error without an error number + * + * @param conn The index of the connection + * @param message_id The ID of the message to which this message is a response + * @param desc The error description to send + * @return 1: Client disconnected + * 0: Success (possibily delayed) + * -1: An error occurred + */ +GCC_ONLY(__attribute__((nonnull))) +int (send_error)(size_t conn, const char* restrict message_id, const char* restrict desc); + +/** + * Send a standard error + * + * @param conn The index of the connection + * @param message_id The ID of the message to which this message is a response + * @param number The value of `errno`, 0 to indicate success + * @return 1: Client disconnected + * 0: Success (possibily delayed) + * -1: An error occurred + */ +GCC_ONLY(__attribute__((nonnull))) +int (send_errno)(size_t conn, const char* restrict message_id, int number); + +/** + * Continue sending the queued messages + * + * @param conn The index of the connection + * @return Zero on success, -1 on error, 1 if disconncted + * EINTR, EAGAIN, EWOULDBLOCK, and ECONNRESET count + * as success (ECONNRESET cause 1 to be returned), + * and are handled appropriately. + */ +static inline int continue_send(size_t conn) +{ + return send_message(conn, NULL, 0); +} + + + +#endif + |