Update picohttpparser.{c,h} with upstream repository

Upstream code doesn't do regular releases, so we need to regularly
sync the code from the upstream repository.  This is synchronization up
to the commit f8d0513 from Jan 29, 2024.

(cherry picked from commit d14a76e115)

lib/isc/picohttpparser.c

@@ -154,17 +154,19 @@ get_token_to_eol(const char *buf, const char *buf_end, const char **token,
 			      "\177\177"; /* allow chars w. MSB set */
 	int found;
 	buf = findchar_fast(buf, buf_end, ranges1, 6, &found);
-	if (found)
+	if (found) {
 		goto FOUND_CTL;
+	}
 #else
 	/* find non-printable char within the next 8 bytes, this is the hottest
 	 * code; manually inlined */
 	while (likely(buf_end - buf >= 8)) {
-#define DOIT()                                           \
-	do {                                             \
-		if (unlikely(!IS_PRINTABLE_ASCII(*buf))) \
-			goto NonPrintable;               \
-		++buf;                                   \
+#define DOIT()                                             \
+	do {                                               \
+		if (unlikely(!IS_PRINTABLE_ASCII(*buf))) { \
+			goto NonPrintable;                 \
+		}                                          \
+		++buf;                                     \
 	} while (0)
 		DOIT();
 		DOIT();
@@ -603,6 +605,8 @@ phr_decode_chunked(struct phr_chunked_decoder *decoder, char *buf,
 	size_t dst = 0, src = 0, bufsz = *_bufsz;
 	ssize_t ret = -2; /* incomplete */
 
+	decoder->_total_read += bufsz;
+
 	while (1) {
 		switch (decoder->_state) {
 		case CHUNKED_IN_CHUNK_SIZE:
@@ -615,6 +619,20 @@ phr_decode_chunked(struct phr_chunked_decoder *decoder, char *buf,
 						ret = -1;
 						goto Exit;
 					}
+					/* the only characters that may appear
+					 * after the chunk size are BWS,
+					 * semicolon, or CRLF */
+					switch (buf[src]) {
+					case ' ':
+					case '\011':
+					case ';':
+					case '\012':
+					case '\015':
+						break;
+					default:
+						ret = -1;
+						goto Exit;
+					}
 					break;
 				}
 				if (decoder->_hex_count == sizeof(size_t) * 2) {
@@ -714,6 +732,15 @@ Exit:
 	if (dst != src)
 		memmove(buf + dst, buf + src, bufsz - src);
 	*_bufsz = dst;
+	/* if incomplete but the overhead of the chunked encoding is >=100KB and
+	 * >80%, signal an error */
+	if (ret == -2) {
+		decoder->_total_overhead += bufsz - dst;
+		if (decoder->_total_overhead >= 100 * 1024 &&
+		    decoder->_total_read - decoder->_total_overhead <
+			    decoder->_total_read / 4)
+			ret = -1;
+	}
 	return ret;
 }
 

lib/isc/picohttpparser.h

@@ -29,6 +29,7 @@
 #ifndef picohttpparser_h
 #define picohttpparser_h
 
+#include <stdint.h>
 #include <sys/types.h>
 
 #ifdef _MSC_VER
@@ -74,6 +75,8 @@ struct phr_chunked_decoder {
 	char consume_trailer;	    /* if trailing headers should be consumed */
 	char _hex_count;
 	char _state;
+	uint64_t _total_read;
+	uint64_t _total_overhead;
 };
 
 /* the function rewrites the buffer given as (buf, bufsz) removing the chunked-