changeset
use non-blocking IO for pipes and socket in send_cgi
Sun, 13 Nov 2022 12:58:25 +0100
- author
- Olaf Wintermann <olaf.wintermann@gmail.com>
- date
- Sun, 13 Nov 2022 12:58:25 +0100
- changeset 433
- 39fe86ae4db0
- parent 432
- 7c9137f9e7f9
- child 434
- ff576305ae6e
use non-blocking IO for pipes and socket in send_cgi
--- a/src/server/daemon/event_bsd.c Sun Nov 13 10:57:38 2022 +0100 +++ b/src/server/daemon/event_bsd.c Sun Nov 13 12:58:25 2022 +0100 @@ -30,6 +30,7 @@ #include <stdlib.h> #include "../util/atomic.h" +#include "../util/io.h" #include "event_bsd.h" @@ -182,3 +183,16 @@ } return event_send(cb->evhandler, cb->event); } + + +int event_pollin(EventHandler *ev, SYS_NETFD fd, Event *event) { + return ((IOStream*)fd)->poll(fd, ev, IO_POLL_IN, event); +} + +int event_pollout(EventHandler *ev, SYS_NETFD fd, Event *event) { + return ((IOStream*)fd)->poll(fd, ev, IO_POLL_OUT, event); +} + +int event_removepoll(EventHandler *ev, SYS_NETFD fd) { + return ((IOStream*)fd)->poll(fd, ev, IO_POLL_NONE, NULL); +}
--- a/src/server/daemon/protocol.c Sun Nov 13 10:57:38 2022 +0100 +++ b/src/server/daemon/protocol.c Sun Nov 13 12:58:25 2022 +0100 @@ -385,6 +385,7 @@ CxBuffer *buf = &writer->buf; // flush buffer to the socket + int ret = 0; while(buf->pos < buf->size) { int w = conn->write(conn, buf->space + buf->pos, buf->size - buf->pos); if(w <= 0) { @@ -397,17 +398,20 @@ return 1; } } - return -1; + ret = -1; + break; } buf->pos += w; } - writer->rq->senthdrs = 1; + if(ret == 0) { + writer->rq->senthdrs = 1; + } cxBufferDestroy(buf); pool_free(writer->sn->pool, writer); - return 0; + return ret; }
--- a/src/server/safs/cgi.c Sun Nov 13 10:57:38 2022 +0100 +++ b/src/server/safs/cgi.c Sun Nov 13 12:58:25 2022 +0100 @@ -179,6 +179,8 @@ handler->writeev = writeev; handler->stderrev = stderr_readev; + net_setnonblock(sn->csd, 1); + // add poll events for cgi stdout/stderr int error = 0; if(ev_pollin(sn->ev, handler->process.err[0], stderr_readev)) { @@ -200,15 +202,96 @@ return REQ_PROCESSING; } +static int cgi_try_write_flush(CGIHandler *handler, Session *sn) { + ssize_t wr = 0; + while( + handler->writebuf_size - handler->writebuf_pos > 0 && + (wr = net_write( + sn->csd, + handler->writebuf + handler->writebuf_pos, + handler->writebuf_size - handler->writebuf_pos)) + > 0) + { + handler->writebuf_pos += wr; + } + if(wr < 0) { + if(errno != EWOULDBLOCK) { + handler->result = REQ_ABORTED; + } + return 1; + } + return 0; +} + +static int cgi_try_write(CGIHandler *handler, EventHandler *ev, Session *sn, char *buf, size_t size) { + size_t pos = 0; + ssize_t wr = 0; + while(size - pos > 0 && (wr = net_write(sn->csd, buf + pos, size - pos)) > 0) { + pos += wr; + } + if(wr < 0) { + if(errno == EWOULDBLOCK) { + // copy remaining bytes to the write buffer + // we assume there are no remaining bytes in writebuf + size_t remaining = size-pos; + if(remaining <= handler->writebuf_alloc) { + memcpy(handler->writebuf, buf+pos, remaining); + } else { + handler->writebuf_alloc = size > 4096 ? size : 4096; + handler->writebuf = pool_realloc(sn->pool, handler->writebuf, handler->writebuf_alloc); + if(!handler->writebuf) { + handler->result = REQ_ABORTED; + return 1; + } + } + handler->writebuf_size = remaining; + handler->writebuf_pos = 0; + + // initialize poll, if it isn't already active + if(!handler->poll_out) { + if(event_pollout(ev, sn->csd, handler->writeev)) { + handler->result = REQ_ABORTED; + return 1; + } + handler->poll_out = TRUE; + } + return 1; + } + handler->result = REQ_ABORTED; + return 1; + } + + return 0; +} + int cgi_stdout_readevent(EventHandler *ev, Event *event) { CGIHandler *handler = event->cookie; + + return cgi_read_output(handler, ev); +} + +int cgi_writeevent(EventHandler *ev, Event *event) { + CGIHandler *handler = event->cookie; + + // cgi_read_output will try to flush the buffer + return cgi_read_output(handler, ev); +} + + + +int cgi_read_output(CGIHandler *handler, EventHandler *ev) { CGIResponseParser *parser = handler->parser; Session *sn = parser->sn; Request *rq = parser->rq; + // try to flush handler->writebuf + // if writebuf is empty, this does nothing and returns 0 + if(cgi_try_write_flush(handler, sn)) { + return handler->result == REQ_ABORTED ? 0 : 1; + } + char buf[4096]; // I/O buffer ssize_t r; - ssize_t wr = 0; handler->result = REQ_PROCEED; while((r = read(handler->process.out[0], buf, 4096)) > 0) { @@ -221,28 +304,51 @@ "broken cgi script response: path: %s", handler->path); protocol_status(sn, rq, 500, NULL); handler->result = REQ_ABORTED; - break; + return 0; } else if(ret == 1) { + WS_ASSERT(pos <= r); + + parser->response_length += r-pos; + parser->cgiheader = FALSE; if(parser->status > 0) { protocol_status(sn, rq, parser->status, parser->msg); } - http_start_response(sn, rq); + + handler->response = http_create_response(sn, rq); + if(!handler->response) { + handler->result = REQ_ABORTED; + return 0; + } + + int send_response = http_send_response(handler->response); + if(send_response < 0) { + handler->result = REQ_ABORTED; + break; + } else if(send_response == 1) { + // EWOULDBLOCK + if(!handler->poll_out) { + if(event_pollout(ev, sn->csd, handler->writeev)) { + handler->result = REQ_ABORTED; + return 0; + } + handler->poll_out = TRUE; + return 1; + } + } else { + handler->response = NULL; + } + if(pos < r) { - parser->response_length += r-pos; - wr = net_write(sn->csd, &buf[pos], r-pos); - if(wr <= 0) { - handler->result = REQ_ABORTED; - break; + if(cgi_try_write(handler, ev, sn, &buf[pos], r-pos)) { + return handler->result == REQ_ABORTED ? 0 : 1; } } } } else { parser->response_length += r; - wr = net_write(sn->csd, buf, r); - if(wr <= 0) { - handler->result = REQ_ABORTED; - break; + if(cgi_try_write(handler, ev, sn, buf, r)) { + return handler->result == REQ_ABORTED ? 0 : 1; } } } @@ -250,21 +356,7 @@ return 1; } - char *ctlen_header = pblock_findkeyval(pb_key_content_length, rq->srvhdrs); - if(ctlen_header) { - int64_t ctlenhdr; - if(util_strtoint(ctlen_header, &ctlenhdr)) { - if(ctlenhdr != parser->response_length) { - log_ereport( - LOG_FAILURE, - "cgi-send: script: %s: content length mismatch", - handler->path); - rq->rq_attr.keep_alive = 0; - handler->result = REQ_ABORTED; - } - } - } - + handler->read_output_finished = TRUE; return 0; } @@ -337,7 +429,7 @@ CGIResponseParser *parser = handler->parser; Session *sn = parser->sn; Request *rq = parser->rq; - + if(handler->result == REQ_ABORTED) { log_ereport(LOG_FAILURE, "cgi-send: kill script: %s", handler->path); kill(handler->process.pid, SIGKILL); @@ -349,6 +441,11 @@ handler->stderrev->finish = cgi_event_finish; return 0; } + if(handler->poll_out && !handler->send_response_finished) { + // send response is still active + handler->writeev->finish = cgi_event_finish; + return 0; + } int exit_code = cgi_close(&handler->process); if(exit_code != 0) { @@ -357,6 +454,27 @@ } cgi_parser_free(parser); + + // check if content-length set by the cgi script matches the number + // of writes, that were written to the stream + // this ensures, that broken cgi scripts don't break the connection + char *ctlen_header = pblock_findkeyval(pb_key_content_length, rq->srvhdrs); + if(ctlen_header) { + int64_t ctlenhdr; + if(util_strtoint(ctlen_header, &ctlenhdr)) { + if(ctlenhdr != parser->response_length) { + log_ereport( + LOG_FAILURE, + "cgi-send: script: %s: content length mismatch", + handler->path); + rq->rq_attr.keep_alive = 0; + handler->result = REQ_ABORTED; + } + } + } + + net_setnonblock(sn->csd, 0); + // return to nsapi loop nsapi_function_return(sn, rq, handler->result); return 0;
--- a/src/server/safs/cgi.h Sun Nov 13 10:57:38 2022 +0100 +++ b/src/server/safs/cgi.h Sun Nov 13 12:58:25 2022 +0100 @@ -56,12 +56,20 @@ typedef struct CGIHandler { CGIProcess process; CGIResponseParser *parser; + HttpResponseWriter *response; char *path; Event *writeev; Event *stderrev; char *stderr_tmp; int stderr_tmplen; + char *writebuf; + size_t writebuf_alloc; + size_t writebuf_size; + size_t writebuf_pos; WSBool stderr_finished; + WSBool read_output_finished; + WSBool send_response_finished; + WSBool poll_out; int result; } CGIHandler; @@ -76,6 +84,9 @@ int cgi_stdout_readevent(EventHandler *ev, Event *event); int cgi_stderr_readevent(EventHandler *ev, Event *event); int cgi_event_finish(EventHandler *ev, Event *event); +int cgi_writeevent(EventHandler *ev, Event *event); + +int cgi_read_output(CGIHandler *handler, EventHandler *ev); CGIResponseParser* cgi_parser_new(Session *sn, Request *rq); void cgi_parser_free(CGIResponseParser *parser);
