/**
* @brief Check to see if the specified command line option specified an optional parameter, and adjust the index accordingly.
* @note This function will automatically generate an error through display_usage() if the parameters are incorrect.
* @param xargv a pointer to the main function's argv array.
* @param iptr a pointer to the xargv option index to be checked and updated.
* @param xargc the number of items in the xargv array.
* @return a pointer to the value of the current index's optional parameter if specified, or NULL if one wasn't.
*/
chr_t * check_next_opt(char *xargv[], int *iptr, int xargc) {
chr_t *result;
// If this is an optional parameter then there still must be a config file specified after it.
if (*iptr == (xargc-1)) {
check_display_usage(xargv[0]);
}
// If the next argument begins with '-' then our option has a null parameter.
else if (!mm_cmp_cs_eq(xargv[*iptr+1], "-", 1)) {
(*iptr)++;
return NULL;
}
// If the following parameter is the last one, it must be the config file and this is a null option.
if (*iptr+1 == (xargc-1)) {
(*iptr)++;
return NULL;
}
(*iptr) += 2;
if (!(result = ns_dupe(xargv[*iptr-1]))) {
log_unit("Memory allocation encountered while preparing checks. Exiting.\n");
}
return result;
}
/**
* @brief Count the number of instances of a boundary string inside a MIME body.
* @note The search is terminated if "--" is found right after the boundary string.
* @param body a placer containing the body text to be parsed.
* @param boundary a pointer to a managed string containing the boundary string for the MIME content.
* @return 0 on failure, or the number of times the boundary string was located in the MIME body on success.
*/
uint32_t mail_mime_count(placer_t body, stringer_t *boundary) {
uint32_t result = 0;
chr_t *stream, *bounddata;
size_t increment = 0, length, boundlen;
if (pl_empty(body) || st_empty(boundary)) {
return 0;
}
// Figure out the lengths.
if (!(length = st_length_get(&body))) {
log_pedantic("Cannot count boundary marker in zero-length MIME body..");
return 0;
}
else if (!(boundlen = st_length_get(boundary))) {
log_pedantic("Cannot count zero-length MIME boundary.");
return 0;
}
// Setup.
stream = st_char_get(&body);
bounddata = st_char_get(boundary);
// Find the start of the first part.
while (increment + boundlen <= length) {
if (mm_cmp_cs_eq(stream, bounddata, boundlen) == 0) {
stream += boundlen + 1;
increment += boundlen + 1;
// Two dashes indicate the end of this mime sections.
if (increment + 1 <= length && mm_cmp_cs_eq(stream, "--", 2) == 0) {
increment = length + 1;
}
else {
result++;
}
}
else {
stream++;
increment++;
}
}
return result;
}
/**
* @brief Get a specified chunk (mime part) of a multipart mime message.
* @param message a managed string containing the mime message to be parsed.
* @param boundary a managed string containing the boundary used to split the multipart mime message.
* @param chunk the one-index based chunk to be retrieved from the multipart message
* @return NULL on failure or a placer containing the specified chunk on success.
*/
stringer_t * mail_get_chunk(stringer_t *message, stringer_t *boundary, int_t chunk) {
int_t found = 0;
stringer_t *result;
size_t start = 0, length = 0, input = 0;
while (chunk != 0) {
// So on repeats we don't have to start all over again.
if (length != 0) {
start += length - 1;
}
found = 0;
while (found == 0) {
// Get the start of the MIME message part.
if (!st_search_cs(PLACER(st_char_get(message) + start, st_length_get(message) - start), boundary, &input)) {
log_pedantic("The boundary doesn't appear to be part of this message.");
return NULL;
}
// Skip the boundary before searching again.
start += input + st_length_get(boundary);
// This will detect the section ending.
if (st_length_get(message) - start >= 2 && mm_cmp_cs_eq(st_char_get(message) + start, "--", 2) == 1) {
return NULL;
}
// Some broken implementations use similar boundaries. This should detect those.
else if (st_length_get(message) - start > 0 && (*(st_char_get(message) + start) < '!' || *(st_char_get(message) + start) > '~')) {
found = 1;
}
}
found = 0;
while (found == 0) {
// Get the end.
if (!st_search_cs(PLACER(st_char_get(message) + start, st_length_get(message) - start), boundary, &length)) {
length = st_length_get(message) - start;
found = 1;
}
else if (st_length_get(message) - start - length > 0 && (*(st_char_get(message) + start) < '!' || *(st_char_get(message) + start) > '~')) {
found = 1;
}
}
chunk--;
}
// Setup a placer with the chunk.
result = PLACER(st_char_get(message) + start, length);
return result;
}
/**
* @brief Get the media type for a given file extension.
* @note If no direct match is found for the content, "application/octet-stream" will be returned.
* @param extension a pointer to a null-terminated string containing the file extension to be looked up, starting with a period.
* @return a pointer to a media type object corresponding to the media type of the specified file extension.
*/
media_type_t * mail_mime_get_media_type (chr_t *extension) {
size_t cmplen = ns_length_get(extension) + 1;
for (size_t i = 1; i < sizeof(media_types) / sizeof(media_type_t); i++) {
if (!mm_cmp_cs_eq(media_types[i].extension, extension, cmplen)) {
return (&(media_types[i]));
}
}
return (&(media_types[0]));
}
/* modeled closely after args_parse() */
void check_args_parse(int argc, char *argv[]) {
int_t i = 1;
while (i < argc) {
if (!st_cmp_cs_eq(NULLER(argv[i]), PLACER("-v", 2))) {
if (!(virus_check_data_path = check_next_opt(argv, &i, argc))) {
do_virus_check = false;
}
}
else if (!st_cmp_cs_eq(NULLER(argv[i]), PLACER("-t", 2))) {
if (!(tank_check_data_path = check_next_opt(argv, &i, argc))) {
do_tank_check = false;
}
}
else if (!st_cmp_cs_eq(NULLER(argv[i]), PLACER("-d", 2))) {
if (!(dspam_check_data_path = check_next_opt(argv, &i, argc))) {
do_dspam_check = false;
}
}
else if (!st_cmp_cs_eq(NULLER(argv[i]), PLACER("-s", 2))) {
do_spf_check = false;
i++;
}
// See if it's an illegal parameter beginning with "-"
else if (!mm_cmp_cs_eq(argv[i], "-", 1)) {
check_display_usage(argv[0]);
}
// Otherwise it's the config file
else if (i == (argc-1)) {
snprintf(magma.config.file, MAGMA_FILEPATH_MAX, "%s", argv[i]);
i++;
}
else {
check_display_usage(argv[0]);
}
}
return;
}
/**
* @brief Get the media type for a given file extension.
* @note If no direct match is found for the content, "application/octet-stream" will be returned.
* @param extension a pointer to a null-terminated string containing the file extension to be looked up, starting with a period.
* @return a pointer to a media type object corresponding to the media type of the specified file extension.
*/
media_type_t * mail_mime_get_media_type (chr_t *extension) {
size_t cmplen = 0;
// If extension is NULL, return application/octet-stream.
if (ns_empty(extension)) return (&(media_types[0]));
cmplen = ns_length_get(extension) + 1;
for (size_t i = 1; i < sizeof(media_types) / sizeof(media_type_t); i++) {
if (!mm_cmp_cs_eq(media_types[i].extension, extension, cmplen)) {
return (&(media_types[i]));
}
}
return (&(media_types[0]));
}
/**
* @brief Get a placer pointing to the specified child inside a MIME body.
* @param body a placer containing the body text to be parsed.
* @param boundary a pointer to a managed string containing the boundary string to split the MIME content.
* @param child the zero-based index of the MIME child to be located in the body text.
* @return pl_null() on failure, or a placer containing the specified MIME child on success.
*/
placer_t mail_mime_child(placer_t body, stringer_t *boundary, uint32_t child) {
uint32_t result = 0;
chr_t *start, *stream, *bounddata;
size_t increment = 0, length, boundlen;
if (pl_empty(body) || st_empty(boundary)) {
return pl_null();
}
// Figure out the lengths.
if (!(length = st_length_get(&body))) {
log_pedantic("Cannot parse children from zero-length MIME body..");
return pl_null();
}
else if (!(boundlen = st_length_get(boundary))) {
log_pedantic("Cannot parse children from MIME body with zero-length boundary.");
return pl_null();;
}
// Setup.
stream = st_char_get(&body);
bounddata = st_char_get(boundary);
// Find the start of the first part.
while (increment + boundlen <= length && result < child) {
if (mm_cmp_cs_eq(stream, bounddata, boundlen) == 0 && (increment + boundlen == length || *(stream + boundlen) < '!' || *(stream + boundlen) > '~')) {
stream += boundlen;
increment += boundlen;
// Two dashes indicate the end of this mime sections.
if (increment < length && mm_cmp_cs_eq(stream, "--", 2) == 0) {
increment = length + 1;
}
else {
result++;
}
}
else {
stream++;
increment++;
}
}
// The requested child wasn't found.
if (increment + boundlen >= length) {
return pl_null();
}
// This will skip a line break after the boundary marker.
if (length - increment > 0 && *stream == '\r') {
stream++;
increment++;
}
if (length - increment > 0 && *stream == '\n') {
stream++;
increment++;
}
// Store the start position.
start = stream;
// Find the end.
while (increment < length) {
if (increment + boundlen < length && mm_cmp_cs_eq(stream, bounddata, boundlen) == 0) {
increment = length;
}
else {
stream++;
increment++;
}
}
// Make sure we advanced.
if (stream == start) {
return pl_null();
}
return pl_init(start, stream - start);
}
