From 90287c2a774ec5f13214db8384a1c730c6c0b83c Mon Sep 17 00:00:00 2001 From: Laurent Vivier Date: Mon, 19 Jan 2026 17:19:14 +0100 Subject: tcp: Register fds with epoll at flow creation Register connection sockets with epoll using empty events (events=0) in tcp_conn_from_tap(), tcp_tap_conn_from_sock() and tcp_flow_repair_socket(). This allows tcp_epoll_ctl() to always use EPOLL_CTL_MOD, removing the need to check whether fds are already registered. As a result, the conditional ADD/MOD logic is no longer needed, simplifying the function. Signed-off-by: Laurent Vivier Reviewed-by: David Gibson Signed-off-by: Stefano Brivio --- flow.c | 1 + tcp.c | 46 ++++++++++++++++++++++++---------------------- 2 files changed, 25 insertions(+), 22 deletions(-) diff --git a/flow.c b/flow.c index 3d2c211..ca569b5 100644 --- a/flow.c +++ b/flow.c @@ -357,6 +357,7 @@ static void flow_set_state(struct flow_common *f, enum flow_state state) * * Return: true if flow is registered with epoll, false otherwise */ +/* cppcheck-suppress unusedFunction */ bool flow_in_epoll(const struct flow_common *f) { return f->epollid != EPOLLFD_ID_INVALID; diff --git a/tcp.c b/tcp.c index 45dde5a..21146de 100644 --- a/tcp.c +++ b/tcp.c @@ -524,37 +524,22 @@ static uint32_t tcp_conn_epoll_events(uint8_t events, uint8_t conn_flags) static int tcp_epoll_ctl(struct tcp_tap_conn *conn) { uint32_t events; - int m; if (conn->events == CLOSED) { - if (flow_in_epoll(&conn->f)) { - int epollfd = flow_epollfd(&conn->f); + int epollfd = flow_epollfd(&conn->f); - epoll_del(epollfd, conn->sock); - if (conn->timer != -1) - epoll_del(epollfd, conn->timer); - } + epoll_del(epollfd, conn->sock); + if (conn->timer != -1) + epoll_del(epollfd, conn->timer); return 0; } events = tcp_conn_epoll_events(conn->events, conn->flags); - if (flow_in_epoll(&conn->f)) { - m = EPOLL_CTL_MOD; - } else { - flow_epollid_set(&conn->f, EPOLLFD_ID_DEFAULT); - m = EPOLL_CTL_ADD; - } - - if (flow_epoll_set(&conn->f, m, events, conn->sock, - !TAPSIDE(conn)) < 0) { - int ret = -errno; - - if (m == EPOLL_CTL_ADD) - flow_epollid_clear(&conn->f); - return ret; - } + if (flow_epoll_set(&conn->f, EPOLL_CTL_MOD, events, conn->sock, + !TAPSIDE(conn)) < 0) + return -errno; return 0; } @@ -1706,6 +1691,11 @@ static void tcp_conn_from_tap(const struct ctx *c, sa_family_t af, conn->sock = s; conn->timer = -1; conn->listening_sock = -1; + flow_epollid_set(&conn->f, EPOLLFD_ID_DEFAULT); + if (flow_epoll_set(&conn->f, EPOLL_CTL_ADD, 0, s, TGTSIDE) < 0) { + flow_perror(flow, "Can't register with epoll"); + goto cancel; + } conn_event(c, conn, TAP_SYN_RCVD); conn->wnd_to_tap = WINDOW_DEFAULT; @@ -2429,6 +2419,15 @@ static void tcp_tap_conn_from_sock(const struct ctx *c, union flow *flow, conn->sock = s; conn->timer = -1; conn->ws_to_tap = conn->ws_from_tap = 0; + + flow_epollid_set(&conn->f, EPOLLFD_ID_DEFAULT); + if (flow_epoll_set(&conn->f, EPOLL_CTL_ADD, 0, s, INISIDE) < 0) { + flow_perror(flow, "Can't register with epoll"); + conn_flag(c, conn, CLOSING); + FLOW_ACTIVATE(conn); + return; + } + conn_event(c, conn, SOCK_ACCEPTED); hash = flow_hash_insert(c, TAP_SIDX(conn)); @@ -3691,6 +3690,9 @@ int tcp_flow_migrate_target(struct ctx *c, int fd) return 0; } + flow_epollid_set(&conn->f, EPOLLFD_ID_DEFAULT); + flow_epoll_set(&conn->f, EPOLL_CTL_ADD, 0, conn->sock, !TAPSIDE(conn)); + flow_hash_insert(c, TAP_SIDX(conn)); FLOW_ACTIVATE(conn); -- cgit v1.2.3