From: Cosmin Ratiu <[email protected]> The psp_responder accumulates received data in a buffer and parses received messages from it, but a message that's split in two across command and argument (e.g. "psp conn" and "1") will permanently choke the parser, because the stand-alone arg is never parsed after discarding the command.
This is mostly a theoretical issue since a sent TCP segment from psp.py of the form "psp conn 1" will arrive in one piece to psp_responder, but the AI tools complain about the possibility that it might get split, so fix it now before another command with an argument is added in the next patch. Signed-off-by: Cosmin Ratiu <[email protected]> Reviewed-by: Dragos Tatulea <[email protected]> Signed-off-by: Tariq Toukan <[email protected]> --- .../selftests/drivers/net/psp_responder.c | 38 +++++++++---------- 1 file changed, 17 insertions(+), 21 deletions(-) diff --git a/tools/testing/selftests/drivers/net/psp_responder.c b/tools/testing/selftests/drivers/net/psp_responder.c index a26e7628bbb1..985161eb482b 100644 --- a/tools/testing/selftests/drivers/net/psp_responder.c +++ b/tools/testing/selftests/drivers/net/psp_responder.c @@ -185,22 +185,22 @@ run_session(struct ynl_sock *ys, struct opts *opts, } off += n; - n = off; #define __consume(sz) \ ({ \ - if (n == (sz)) { \ - off = 0; \ - } else { \ - off -= (sz); \ - memmove(buf, &buf[(sz)], off); \ - } \ + off -= (sz); \ + memmove(buf, &buf[(sz)], off); \ }) -#define cmd(_name) \ +/* Only match once the command and its _extra_sz byte payload are both + * buffered, otherwise a split read would consume the name and strand + * the payload, desynchronizing the parser for good. + */ +#define cmd(_name, _extra_sz) \ ({ \ ssize_t sz = sizeof(_name); \ - bool match = n >= sz && !memcmp(buf, _name, sz); \ + bool match = off >= sz + (_extra_sz) && \ + !memcmp(buf, _name, sz); \ \ if (match) { \ dbg("command: " _name "\n"); \ @@ -213,10 +213,10 @@ run_session(struct ynl_sock *ys, struct opts *opts, do { consumed = false; - if (cmd("read len")) + if (cmd("read len", 0)) send_str(comm_sock, data_read); - if (cmd("data echo")) { + if (cmd("data echo", 0)) { if (data_sock >= 0) send(data_sock, "echo", 5, MSG_WAITALL); @@ -224,7 +224,7 @@ run_session(struct ynl_sock *ys, struct opts *opts, fprintf(stderr, "WARN: echo but no data sock\n"); send_ack(comm_sock); } - if (cmd("data close")) { + if (cmd("data close", 0)) { if (data_sock >= 0) { close(data_sock); data_sock = -1; @@ -233,26 +233,22 @@ run_session(struct ynl_sock *ys, struct opts *opts, race_close = true; } } - if (cmd("conn psp")) { + if (cmd("conn psp", 2)) { if (accept_cfg != ACCEPT_CFG_NONE) fprintf(stderr, "WARN: old conn config still set!\n"); accept_cfg = ACCEPT_CFG_PSP; send_ack(comm_sock); /* next two bytes are versions */ - if (off >= 2) { - memcpy(&psp_vers, buf, 2); - __consume(2); - } else { - fprintf(stderr, "WARN: short conn psp command!\n"); - } + memcpy(&psp_vers, buf, 2); + __consume(2); } - if (cmd("conn clr")) { + if (cmd("conn clr", 0)) { if (accept_cfg != ACCEPT_CFG_NONE) fprintf(stderr, "WARN: old conn config still set!\n"); accept_cfg = ACCEPT_CFG_CLEAR; send_ack(comm_sock); } - if (cmd("exit")) + if (cmd("exit", 0)) should_quit = true; #undef cmd -- 2.44.0
