From 97524874078bad74582c25f9b1dbbb1f699ef11d Mon Sep 17 00:00:00 2001 From: Mattias Andrée Date: Tue, 25 Aug 2015 01:53:09 +0200 Subject: libmdsclient: add message composing function MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Mattias Andrée --- src/libmdsclient/proto-util.c | 180 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 180 insertions(+) (limited to 'src/libmdsclient/proto-util.c') diff --git a/src/libmdsclient/proto-util.c b/src/libmdsclient/proto-util.c index 1b5e7be..f104d05 100644 --- a/src/libmdsclient/proto-util.c +++ b/src/libmdsclient/proto-util.c @@ -15,11 +15,15 @@ * You should have received a copy of the GNU General Public License * along with this program. If not, see . */ +#ifndef _GNU_SOURCE +# define _GNU_SOURCE +#endif #include "proto-util.h" #include #include #include +#include @@ -563,3 +567,179 @@ void libmds_headers_sort(char** restrict headers, size_t header_count) qsort(headers, header_count, sizeof(char*), headerpcmp); } + +/** + * Compose a message + * + * @param buffer Pointer to the buffer where the message should be written, + * may point to `NULL` if `buffer_size` points to zero, but the + * pointer itself must not be `NULL`. The buffer may be reallocated. + * Will be updated with the new buffer it is allocated. + * The buffer the pointer points to will be filled with the + * message, however there is no guarantee it will be NUL-terminated. + * @param buffer_size The allocation size, in `char`, of `*buffer`, if and only if `buffer` + * points to `NULL`, this point should point to zero, and vice versa. + * Must not be `NULL`. Will be update with the new allocation size. + * It is guaranteed that there will be remove to NUL-terminate + * the message even if it was already NUL-terminate (terminate it + * doubly in that case.) + * @param length Output parameter for the length of the constructed message. + * Must not be `NULL`. + * @param payload The payload that should be added to the message, it should end + * with a LF. `NULL` if the message should not have a payload. + * @param payload_length Pointer to the length of the payload. If `NULL`, `payload` + * must be NUL-terminated, and if it is `NULL` this NUL-termination + * will be used to find the length of the payload. This variable is + * not used if `payload` is `NULL`. + * @param ... The first argument should be a line describing the first header, + * it should be a printf(3)-formatted line that fully describes the + * header line, that is, the header name, colon, blank space and then + * the header's value. No LF should be included. The following + * arguments should be the argument to format the header line. + * This may be be iterated any number of this. The last argument + * should be `NULL` to specify that there are no more headers. + * The `Length`-header should not be included, it is added automatically. + * A header may not have a length larger than 2¹⁵, otherwise + * the behaviour of this function is undefined. + * @return Zero on success, -1 on error, `errno` will have been set + * accordingly on error. + * + * @throws ENOMEM Out of memory, Possibly, the process hit the RLIMIT_AS or + * RLIMIT_DATA limit described in getrlimit(2). + */ +int libmds_compose(char** restrict buffer, size_t* restrict buffer_size, size_t* restrict length, + const char* restrict payload, const size_t* restrict payload_length, ...) +{ + va_list args; + int r, saved_errno; + va_start(args, payload_length); + r = libmds_compose_v(buffer, buffer_size, length, payload, payload_length, args); + saved_errno = errno; + va_end(args); + errno = saved_errno; + return r; +} + + +/** + * Compose a message + * + * @param buffer Pointer to the buffer where the message should be written, + * may point to `NULL` if `buffer_size` points to zero, but the + * pointer itself must not be `NULL`. The buffer may be reallocated. + * Will be updated with the new buffer it is allocated. + * The buffer the pointer points to will be filled with the + * message, however there is no guarantee it will be NUL-terminated. + * @param buffer_size The allocation size, in `char`, of `*buffer`, if and only if `buffer` + * points to `NULL`, this point should point to zero, and vice versa. + * Must not be `NULL`. Will be update with the new allocation size. + * It is guaranteed that there will be remove to NUL-terminate + * the message even if it was already NUL-terminate (terminate it + * doubly in that case.) + * @param length Output parameter for the length of the constructed message. + * Must not be `NULL`. + * @param payload The payload that should be added to the message, it should end + * with a LF. `NULL` if the message should not have a payload. + * @param payload_length Pointer to the length of the payload. If `NULL`, `payload` + * must be NUL-terminated, and if it is `NULL` this NUL-termination + * will be used to find the length of the payload. This variable is + * not used if `payload` is `NULL`. + * @param args The first argument should be a line describing the first header, + * it should be a printf(3)-formatted line that fully describes the + * header line, that is, the header name, colon, blank space and then + * the header's value. No LF should be included. The following + * arguments should be the argument to format the header line. + * This may be be iterated any number of this. The last argument + * should be `NULL` to specify that there are no more headers. + * The `Length`-header should not be included, it is added automatically. + * A header may not have a length larger than 2¹⁵, otherwise + * the behaviour of this function is undefined. + * @return Zero on success, -1 on error, `errno` will have been set + * accordingly on error. + * + * @throws ENOMEM Out of memory, Possibly, the process hit the RLIMIT_AS or + * RLIMIT_DATA limit described in getrlimit(2). + */ +int libmds_compose_v(char** restrict buffer, size_t* restrict buffer_size, size_t* restrict length, + const char* restrict payload, const size_t* restrict payload_length, va_list args) +{ + char* buf = *buffer; + size_t bufsize = *buffer_size; + size_t len = 0; + int part_len; + char* part_msg; + size_t payload_len = 0; + const char* format; + int saved_errno; + + *length = 0; + + if (payload != NULL) + payload_len = payload_length == NULL ? strlen(payload) : *payload_length; + + if (bufsize == 0) + { + bufsize = 128; + buf = realloc(buf, bufsize * sizeof(char)); + if (buf == NULL) + return -1; + } + + for (;;) + { + format = va_arg(args, const char*); + if (format == NULL) + break; + +# pragma GCC diagnostic push +# pragma GCC diagnostic ignored "-Wformat-nonliteral" + part_len = vasprintf(&part_msg, format, args); +# pragma GCC diagnostic pop + if (part_len < 0) + return -1; + + if (len + (size_t)part_len >= bufsize) + { + *buffer_size = bufsize; + *buffer = buf; + do + bufsize <<= 1; + while (len + (size_t)part_len >= bufsize); + buf = realloc(buf, bufsize * sizeof(char)); + if (buf == NULL) + return saved_errno = errno, free(part_msg), errno = saved_errno, -1; + } + + memcpy(buf + len, part_msg, ((size_t)part_len) * sizeof(char)); + len += (size_t)part_len; + buf[len++] = '\n'; + free(part_msg); + } + +#define LENGTH_LEN \ + (payload_len > 0 ? ((sizeof("Length: \n") / sizeof(char) - 1) + 3 * sizeof(size_t)) : 0) + if (len + LENGTH_LEN + 1 + payload_len + 1 > bufsize) + { + *buffer_size = bufsize; + *buffer = buf; + bufsize = len + LENGTH_LEN + 1 + payload_len + 1; + buf = realloc(buf, bufsize * sizeof(char)); + if (buf == NULL) + return -1; + } +#undef LENGTH_LEN + + if (payload_len > 0) + sprintf(buf + len, "Length: %zu\n%n", payload_len, &part_len), + len += (size_t)part_len; + buf[len++] = '\n'; + if (payload_len > 0) + memcpy(buf + len, payload, payload_len * sizeof(char)), + len += payload_len; + + *buffer_size = bufsize; + *buffer = buf; + *length = len; + return 0; +} + -- cgit v1.2.3-70-g09d2