By mimicking mnl_nft_event_listener() code, mnl_batch_talk() may be simplified quite a bit:
* Turn the conditional loop into an unconditional one. * Call select() at loop start, which merges the two call sites. * Check readfds content after select() returned instead of in loop condition - if fd is not set, break to return error state stored in 'err' variable. * Old code checked that select() return code is > 0, but that was redundant: if FD_ISSET() returns true, select return code was 1. * Move 'nlh' helper variable definition into error handling block, it is not used outside of it. Signed-off-by: Phil Sutter <[email protected]> --- src/mnl.c | 26 +++++++++++--------------- 1 file changed, 11 insertions(+), 15 deletions(-) diff --git a/src/mnl.c b/src/mnl.c index 492d7517d40e2..724decad2e44d 100644 --- a/src/mnl.c +++ b/src/mnl.c @@ -278,16 +278,17 @@ int mnl_batch_talk(struct netlink_ctx *ctx, struct list_head *err_list) if (ret == -1) return -1; - FD_ZERO(&readfds); - FD_SET(fd, &readfds); - /* receive and digest all the acknowledgments from the kernel. */ - ret = select(fd+1, &readfds, NULL, NULL, &tv); - if (ret == -1) - return -1; + while (true) { + FD_ZERO(&readfds); + FD_SET(fd, &readfds); + + ret = select(fd+1, &readfds, NULL, NULL, &tv); + if (ret == -1) + return -1; - while (ret > 0 && FD_ISSET(fd, &readfds)) { - struct nlmsghdr *nlh = (struct nlmsghdr *)rcv_buf; + if (!FD_ISSET(fd, &readfds)) + break; ret = mnl_socket_recvfrom(nl, rcv_buf, sizeof(rcv_buf)); if (ret == -1) @@ -296,16 +297,11 @@ int mnl_batch_talk(struct netlink_ctx *ctx, struct list_head *err_list) ret = mnl_cb_run(rcv_buf, ret, 0, portid, &netlink_echo_callback, ctx); /* Continue on error, make sure we get all acknowledgments */ if (ret == -1) { + struct nlmsghdr *nlh = (struct nlmsghdr *)rcv_buf; + mnl_err_list_node_add(err_list, errno, nlh->nlmsg_seq); err = -1; } - - FD_ZERO(&readfds); - FD_SET(fd, &readfds); - - ret = select(fd+1, &readfds, NULL, NULL, &tv); - if (ret == -1) - return -1; } return err; } -- 2.21.0
