diff options
| -rw-r--r-- | src/libmdsserver/mds-message.c | 110 |
1 files changed, 78 insertions, 32 deletions
diff --git a/src/libmdsserver/mds-message.c b/src/libmdsserver/mds-message.c index 6463c2b..b05b0cf 100644 --- a/src/libmdsserver/mds-message.c +++ b/src/libmdsserver/mds-message.c @@ -89,6 +89,71 @@ void mds_message_destroy(mds_message_t* restrict this) /** + * Read the headers the message and determine, and store, its payload's length + * + * @param this The message + * @return Zero on success, negative on error (malformated message: unrecoverable state) + */ +static int get_payload_length(mds_message_t* restrict this) +{ + char* header; + size_t i; + + for (i = 0; i < this->header_count; i++) + if (strstr(this->headers[i], "Length: ") == this->headers[i]) + { + /* Store the message length. */ + header = this->headers[i] + strlen("Length: "); + this->payload_size = (size_t)atoll(header); + + /* Do not except a length that is not correctly formated. */ + for (; *header; header++) + if ((*header < '0') || ('9' < *header)) + return -2; /* Malformated value, enters unrecoverable state. */ + + /* Stop searching for the ‘Length’ header, we have found and parsed it. */ + break; + } + + return 0; +} + + +/** + * Verify that a header is correctly formated + * + * @param header The header, must be NUL-terminated + * @param length The length of the header + * @return Zero if valid, negative if invalid (malformated message: unrecoverable state) + */ +static int __attribute__((pure)) validate_header(const char* header, size_t length) +{ + char* p = memchr(header, ':', length * sizeof(char)); + + if ((p == NULL) || /* Buck you, rawmemchr should not segfault the program. */ + (p[1] != ' ')) /* Also an invalid format. ' ' is mandated after the ':'. */ + return -2; + + return 0; +} + + +/** + * Remove the beginning of the read buffer + * + * @param this The message + * @param length The number of characters to remove + * @param update_ptr Whether to update the buffer pointer + */ +static void unbuffer_beginning(mds_message_t* restrict this, size_t length, int update_ptr) +{ + memmove(this->buffer, this->buffer + length, (this->buffer_ptr - length) * sizeof(char)); + if (update_ptr) + this->buffer_ptr -= length; +} + + +/** * Read the next message from a file descriptor * * @param this Memory slot in which to store the new message @@ -128,7 +193,7 @@ 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, i; + size_t n; ssize_t got; char* p; @@ -140,28 +205,15 @@ int mds_message_read(mds_message_t* restrict this, int fd) size_t len = (size_t)(p - this->buffer) + 1; char* header; - /* We have found an empty line, i.e. the end of the headers.*/ + /* We have found an empty line, i.e. the end of the headers. */ if (len == 1) { /* Remove the \n (end of empty line) we found from the buffer. */ - memmove(this->buffer, this->buffer + 1, (this->buffer_ptr -= 1) * sizeof(char)); + unbuffer_beginning(this, 1, 1); /* Get the length of the payload. */ - for (i = 0; i < this->header_count; i++) - if (strstr(this->headers[i], "Length: ") == this->headers[i]) - { - /* Store the message length. */ - header = this->headers[i] + strlen("Length: "); - this->payload_size = (size_t)atoll(header); - - /* Do not except a length that is not correctly formated. */ - for (; *header; header++) - if ((*header < '0') || ('9' < *header)) - return -2; /* Malformated value, enters unrecoverable state. */ - - /* Stop searching for the ‘Length’ header, we have found and parsed it. */ - break; - } + if (get_payload_length(this) < 0) + return -2; /* Malformated value, enters unrecoverable state. */ /* Allocate the payload buffer. */ if (this->payload_size > 0) @@ -177,7 +229,7 @@ int mds_message_read(mds_message_t* restrict this, int fd) /* We have found a header. */ - /* One every eighth heaer found with this function call, + /* One every eighth header found with this function call, we prepare the header list for eight more headers so that it does not need to be reallocated again and again. */ if (header_commit_buffer == 0) @@ -188,11 +240,11 @@ int mds_message_read(mds_message_t* restrict this, int fd) if (xrealloc(this->headers, n, char*)) { this->headers = old_headers; - return -1; + return -1; } } - /* Allocat the header.*/ + /* Allocate the header. */ if (xmalloc(header, len, char)) return -1; /* Copy the header data into the allocated header, */ @@ -201,17 +253,11 @@ int mds_message_read(mds_message_t* restrict this, int fd) header[len - 1] = '\0'; /* Remove the header data from the read buffer. */ - memmove(this->buffer, this->buffer + len, (this->buffer_ptr -= len) * sizeof(char)); + unbuffer_beginning(this, len, 1); - /* Make sure the the header syntex is correct so the the - program does not need to care about it. */ - if ((p = memchr(header, ':', len * sizeof(char))) == NULL) - { - /* Buck you, rawmemchr should not segfault the program. */ - free(header); - return -2; - } - if (p[1] != ' ') /* Also an invalid format. */ + /* Make sure the the header syntax is correct so that + the program does not need to care about it. */ + if (validate_header(header, len)) { free(header); return -2; @@ -239,7 +285,7 @@ int mds_message_read(mds_message_t* restrict this, int fd) { /* Otherwise, copy what we have, and remove it from the the read buffer. */ memcpy(this->payload + this->payload_ptr, this->buffer, need * sizeof(char)); - memmove(this->buffer, this->buffer + need, (this->buffer_ptr - need) * sizeof(char)); + unbuffer_beginning(this, need, 0); } /* Keep track of how much we have read. */ |