diff options
Diffstat (limited to '')
| -rw-r--r-- | src/libmdsserver/mds-message.c | 122 |
1 files changed, 69 insertions, 53 deletions
diff --git a/src/libmdsserver/mds-message.c b/src/libmdsserver/mds-message.c index ea4e458..c70bb15 100644 --- a/src/libmdsserver/mds-message.c +++ b/src/libmdsserver/mds-message.c @@ -26,6 +26,9 @@ #include <sys/socket.h> +#define try(INSTRUCTION) if ((r = INSTRUCTION) < 0) return r + + /** * Initialise a message slot so that it can * be used by `mds_message_read` @@ -272,10 +275,52 @@ static int store_header(mds_message_t* restrict this, size_t length) /** - * Read the next message from a file descriptor + * Continue reading from the socket into the buffer + * + * @param this The message + * @param fd The file descriptor of the socekt + * @return The return value follows the rules of `mds_message_read` + */ +static int continue_read(mds_message_t* restrict this, int fd) +{ + size_t n; + ssize_t got; + int r; + + /* Figure out how much space we have left in the read buffer. */ + n = this->buffer_size - this->buffer_ptr; + + /* If we do not have too much left, */ + if (n < 128) + { + /* grow the buffer, */ + try (mds_message_extend_buffer(this)); + + /* and recalculate how much space we have left. */ + n = this->buffer_size - this->buffer_ptr; + } + + /* Then read from the socket. */ + errno = 0; + got = recv(fd, this->buffer + this->buffer_ptr, n, 0); + this->buffer_ptr += (size_t)(got < 0 ? 0 : got); + if (errno) + return -1; + if (got == 0) + { + errno = ECONNRESET; + return -1; + } + + return 0; +} + + +/** + * Read the next message from a file descriptor of the socekt * * @param this Memory slot in which to store the new message - * @param fd The file descriptor + * @param fd The file descriptor of the socekt * @return Non-zero on error or interruption, errno will be * set accordingly. Destroy the message on error, * be aware that the reading could have been @@ -289,8 +334,6 @@ int mds_message_read(mds_message_t* restrict this, int fd) size_t header_commit_buffer = 0; int r; -#define try(INSTRUCTION) if ((r = INSTRUCTION) < 0) return r - /* If we are at stage 2, we are done and it is time to start over. This is important because the function could have been interrupted. */ if (this->stage == 2) @@ -302,8 +345,6 @@ int mds_message_read(mds_message_t* restrict this, int fd) /* Read from file descriptor until we have a full message. */ for (;;) { - size_t n; - ssize_t got; char* p; size_t length; @@ -337,12 +378,8 @@ int mds_message_read(mds_message_t* restrict this, int fd) this->stage = 1; } + /* Stage 1: payload. */ - if ((this->stage == 1) && (this->payload_size == 0)) - { - this->stage = 2; - return 0; - } if ((this->stage == 1) && (this->payload_size > 0)) { /* How much of the payload that has not yet been filled. */ @@ -356,45 +393,22 @@ int mds_message_read(mds_message_t* restrict this, int fd) /* Keep track of how much we have read. */ this->payload_ptr += move; - - /* If we have filled the payload, make the end of this stage, - i.e. that the message is complete, and return with success. */ - if (this->payload_ptr == this->payload_size) - { - this->stage = 2; - return 0; - } } - - /* If stage 1 was not completed. */ - - /* Figure out how much space we have left in the read buffer. */ - n = this->buffer_size - this->buffer_ptr; - - /* If we do not have too much left, */ - if (n < 128) + if ((this->stage == 1) && (this->payload_ptr == this->payload_size)) { - /* grow the buffer, */ - try (mds_message_extend_buffer(this)); - - /* and recalculate how much space we have left. */ - n = this->buffer_size - this->buffer_ptr; + /* If we have filled the payload (or there was no payload), + mark the end of this stage, i.e. that the message is + complete, and return with success. */ + this->stage = 2; + return 0; } - /* Then read from the socket. */ - errno = 0; - got = recv(fd, this->buffer + this->buffer_ptr, n, 0); - this->buffer_ptr += (size_t)(got < 0 ? 0 : got); - if (errno) - return -1; - if (got == 0) - { - errno = ECONNRESET; - return -1; - } + + /* If stage 1 was not completed. */ + + /* Continue reading from the socket into the buffer. */ + try (continue_read(this, fd)); } - -#undef try } @@ -501,23 +515,19 @@ int mds_message_unmarshal(mds_message_t* restrict this, char* restrict data) /* Allocate header list, payload and read buffer. */ if (header_count > 0) - if (xmalloc(this->headers, header_count, char*)) - return -1; + fail_if (xmalloc(this->headers, header_count, char*)); if (this->payload_size > 0) - if (xmalloc(this->payload, this->payload_size, char)) - return -1; + fail_if (xmalloc(this->payload, this->payload_size, char)); - if (xmalloc(this->buffer, this->buffer_size, char)) - return -1; + fail_if (xmalloc(this->buffer, this->buffer_size, char)); /* Fill the header list, payload and read buffer. */ for (i = 0; i < this->header_count; i++) { n = strlen(data) + 1; - if (xmalloc(this->headers[i], n, char)) - return -1; + fail_if (xmalloc(this->headers[i], n, char)); memcpy(this->headers[i], data, n * sizeof(char)); buf_next(data, char, n); this->header_count++; @@ -529,6 +539,9 @@ int mds_message_unmarshal(mds_message_t* restrict this, char* restrict data) memcpy(this->buffer, data, this->buffer_ptr * sizeof(char)); return 0; + + pfail: + return -1; } @@ -572,3 +585,6 @@ void mds_message_compose(const mds_message_t* restrict this, char* restrict data memcpy(data, this->payload, this->payload_size * sizeof(char)); } + +#undef try + |