Tiny HTTP/1.x request and response parser

Provides a minimal, dependency-free HTTP/1.x request parser.

Provides a minimal, dependency-free HTTP/1.x request parser.

PicoHTTPParser is a tiny, primitive, fast HTTP request/response parser.

It only parses HTTP/1.x requests and responses. It is neither a webserver, nor an HTTP client. It does not open sockets, allocate buffer bodies or build responses. Unlike most parsers, it is stateless and does not allocate memory by itself. All it does is accept a pointer to the buffer and the output structure, and sets up the pointers in the latter to point at the necessary portions of the buffer.

Usage

The parser must be added to the Makefile with

USEPKG += picohttpparser

Then, include the header file picohttpparser.h and start using the phr_parse_request or phr_parse_response functions. Both implementations do not copy the data, they only set pointers to the data in the buffer, so the buffer must remain valid during processing.

As a request parser

Below is a minimal example of how to use the parser to parse an HTTP request that is stored in a buffer request.

#define MAX_HEADERS 8
 
const char *method;
size_t method_len;
const char *path;
size_t path_len;
int minor_version;
struct phr_header headers[MAX_HEADERS];
size_t num_headers = MAX_HEADERS;
 
int res = phr_parse_request(request, sizeof(request) - 1, &method, &method_len,
                            &path, &path_len, &minor_version, headers,
                            &num_headers, 0);
 
if (res == -2) {
    /* request is incomplete, need more data */
}
else if (res == -1) {
    /* request is invalid */
}
else {
    /* request is valid, res points to the start of the body (if any) */
}

As a response parser

Below is a minimal example of how to use the parser to parse an HTTP response that is stored in a buffer response.

#define MAX_HEADERS 8
 
int minor_version;
int status;
const char *msg;
size_t msg_len;
struct phr_header headers[MAX_HEADERS];
size_t num_headers = MAX_HEADERS;
 
int res = phr_parse_response(response, sizeof(response) - 1, &minor_version,
                             &status, &msg, &msg_len, headers, &num_headers, 0);
 
if (res == -2) {
    /* response is incomplete, need more data */
}
else if (res == -1) {
    /* response is invalid */
}
else {
    /* response is valid, res points to the start of the body (if any) */
}