From c6b822428a0225cce7bf5698c6681ee6fad36046 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Thu, 17 Nov 2022 16:58:42 +1100 Subject: tcp_splice: Helpers for converting from index to/from tcp_splice_conn Like we already have for non-spliced connections, create a CONN_IDX() macro for looking up the index of spliced connection structures. Change the name of the array of spliced connections to be different from that for non-spliced connections (even though they're in different modules). This will make subsequent changes a bit safer. Signed-off-by: David Gibson Signed-off-by: Stefano Brivio --- tcp_splice.c | 43 +++++++++++++++++++++++++------------------ 1 file changed, 25 insertions(+), 18 deletions(-) (limited to 'tcp_splice.c') diff --git a/tcp_splice.c b/tcp_splice.c index 3c5c111..4cc4ad2 100644 --- a/tcp_splice.c +++ b/tcp_splice.c @@ -13,10 +13,11 @@ * DOC: Theory of Operation * * - * For local traffic directed to TCP ports configured for direct mapping between - * namespaces, packets are directly translated between L4 sockets using a pair - * of splice() syscalls. These connections are tracked in the @tc array of - * struct tcp_splice_conn, using these events: + * For local traffic directed to TCP ports configured for direct + * mapping between namespaces, packets are directly translated between + * L4 sockets using a pair of splice() syscalls. These connections are + * tracked in the @tc_splice array of struct tcp_splice_conn, using + * these events: * * - SPLICE_CONNECT: connection accepted, connecting to target * - SPLICE_ESTABLISHED: connection to target established @@ -113,10 +114,11 @@ struct tcp_splice_conn { #define CONN_V6(x) (x->flags & SOCK_V6) #define CONN_V4(x) (!CONN_V6(x)) #define CONN_HAS(conn, set) ((conn->events & (set)) == (set)) -#define CONN(index) (tc + (index)) +#define CONN(index) (tc_splice + (index)) +#define CONN_IDX(conn) ((conn) - tc_splice) /* Spliced connections */ -static struct tcp_splice_conn tc[TCP_SPLICE_MAX_CONNS]; +static struct tcp_splice_conn tc_splice[TCP_SPLICE_MAX_CONNS]; /* Display strings for connection events */ static const char *tcp_splice_event_str[] __attribute((__unused__)) = { @@ -173,7 +175,7 @@ static void conn_flag_do(const struct ctx *c, struct tcp_splice_conn *conn, conn->flags &= flag; if (fls(~flag) >= 0) { - debug("TCP (spliced): index %li: %s dropped", conn - tc, + debug("TCP (spliced): index %li: %s dropped", CONN_IDX(conn), tcp_splice_flag_str[fls(~flag)]); } } else { @@ -182,7 +184,7 @@ static void conn_flag_do(const struct ctx *c, struct tcp_splice_conn *conn, conn->flags |= flag; if (fls(flag) >= 0) { - debug("TCP (spliced): index %li: %s", conn - tc, + debug("TCP (spliced): index %li: %s", CONN_IDX(conn), tcp_splice_flag_str[fls(flag)]); } } @@ -211,11 +213,11 @@ static int tcp_splice_epoll_ctl(const struct ctx *c, int m = (conn->flags & IN_EPOLL) ? EPOLL_CTL_MOD : EPOLL_CTL_ADD; union epoll_ref ref_a = { .r.proto = IPPROTO_TCP, .r.s = conn->a, .r.p.tcp.tcp.splice = 1, - .r.p.tcp.tcp.index = conn - tc, + .r.p.tcp.tcp.index = CONN_IDX(conn), .r.p.tcp.tcp.v6 = CONN_V6(conn) }; union epoll_ref ref_b = { .r.proto = IPPROTO_TCP, .r.s = conn->b, .r.p.tcp.tcp.splice = 1, - .r.p.tcp.tcp.index = conn - tc, + .r.p.tcp.tcp.index = CONN_IDX(conn), .r.p.tcp.tcp.v6 = CONN_V6(conn) }; struct epoll_event ev_a = { .data.u64 = ref_a.u64 }; struct epoll_event ev_b = { .data.u64 = ref_b.u64 }; @@ -257,7 +259,7 @@ static void conn_event_do(const struct ctx *c, struct tcp_splice_conn *conn, conn->events &= event; if (fls(~event) >= 0) { - debug("TCP (spliced): index %li, ~%s", conn - tc, + debug("TCP (spliced): index %li, ~%s", CONN_IDX(conn), tcp_splice_event_str[fls(~event)]); } } else { @@ -266,7 +268,7 @@ static void conn_event_do(const struct ctx *c, struct tcp_splice_conn *conn, conn->events |= event; if (fls(event) >= 0) { - debug("TCP (spliced): index %li, %s", conn - tc, + debug("TCP (spliced): index %li, %s", CONN_IDX(conn), tcp_splice_event_str[fls(event)]); } } @@ -292,8 +294,8 @@ static void tcp_table_splice_compact(struct ctx *c, { struct tcp_splice_conn *move; - if ((hole - tc) == --c->tcp.splice_conn_count) { - debug("TCP (spliced): index %li (max) removed", hole - tc); + if (CONN_IDX(hole) == --c->tcp.splice_conn_count) { + debug("TCP (spliced): index %li (max) removed", CONN_IDX(hole)); return; } @@ -307,7 +309,8 @@ static void tcp_table_splice_compact(struct ctx *c, move->pipe_b_a[0] = move->pipe_b_a[1] = -1; move->flags = move->events = 0; - debug("TCP (spliced): index %li moved to %li", move - tc, hole - tc); + debug("TCP (spliced): index %li moved to %li", + CONN_IDX(move), CONN_IDX(hole)); tcp_splice_epoll_ctl(c, hole); if (tcp_splice_epoll_ctl(c, hole)) conn_flag(c, hole, CLOSING); @@ -345,7 +348,7 @@ static void tcp_splice_destroy(struct ctx *c, struct tcp_splice_conn *conn) conn->events = CLOSED; conn->flags = 0; - debug("TCP (spliced): index %li, CLOSED", conn - tc); + debug("TCP (spliced): index %li, CLOSED", CONN_IDX(conn)); tcp_table_splice_compact(c, conn); } @@ -872,7 +875,9 @@ void tcp_splice_timer(struct ctx *c) { struct tcp_splice_conn *conn; - for (conn = CONN(c->tcp.splice_conn_count - 1); conn >= tc; conn--) { + for (conn = CONN(c->tcp.splice_conn_count - 1); + conn >= tc_splice; + conn--) { if (conn->flags & CLOSING) { tcp_splice_destroy(c, conn); return; @@ -918,7 +923,9 @@ void tcp_splice_defer_handler(struct ctx *c) if (c->tcp.splice_conn_count < MIN(max_files / 6, max_conns)) return; - for (conn = CONN(c->tcp.splice_conn_count - 1); conn >= tc; conn--) { + for (conn = CONN(c->tcp.splice_conn_count - 1); + conn >= tc_splice; + conn--) { if (conn->flags & CLOSING) tcp_splice_destroy(c, conn); } -- cgit v1.2.3