On Wed, 5 Jun 2024 17:21:24 +0200 Laurent Vivier <lvivier(a)redhat.com> wrote:Consolidate pool_tap4() and pool_tap6() into pool_flush_all(), and tap4_handler() and tap6_handler() into tap_handler_all(). Create a generic packet_add_all() to consolidate packet addition logic and reduce code duplication. The purpose is to ease the export of these functions to use them with the vhost-user backend. Signed-off-by: Laurent Vivier <lvivier(a)redhat.com> --- tap.c | 113 +++++++++++++++++++++++++++++++++------------------------- tap.h | 7 ++++ 2 files changed, 71 insertions(+), 49 deletions(-) diff --git a/tap.c b/tap.c index 2ea08491a51f..5fb3cb83f3d2 100644 --- a/tap.c +++ b/tap.c @@ -920,6 +920,61 @@ append: return in->count; } +/** + * pool_flush() - Flush both IPv4 and IPv6 packet pools + */ +void pool_flush_all(void) +{ + pool_flush(pool_tap4); + pool_flush(pool_tap6); +} + +/** + * tap_handler_all() - IPv4/IPv4 and ARP packet handler for tap file descriptorIPv4/IPv6+ * @c: Execution context + * @now: Current timestamp + */ +void tap_handler_all(struct ctx *c, const struct timespec *now)I wonder if this shouldn't be named tap_handler() instead. As we already have tap_handler_passt() and tap_handler_pasta(), it's not immediately clear what "all" refers to.+{ + tap4_handler(c, pool_tap4, now); + tap6_handler(c, pool_tap6, now); +} + +/** + * packet_add_all_do() - Add a packet to the appropriate TAP poolA couple of remarks here: - it's a bit unexpected that this is still in tap.c (it adds packets to a pool, it should be in packet.c judging by this name/description). If we call it tap_queue_packet(), then it probably makes more sense? - this does more than adding a packet to a pool. It's probably useless to describe in detail what this does, as the function body is anyway rather short and clear, but the current description could be a bit misleading. What about "Queue/capture packet, update notion of guest MAC address"? - what happens if you just call packet_add() from here, without dealing with 'func' and 'line'? I think it's fine to print in tracing output name and lines from this function, instead of the ones from the caller. It's obvious who the caller is+ * @c: Execution context + * @l2len: Total L2 packet length + * @p: Packet buffer + * @func: For tracing: name of calling function, NULL means no trace() + * @line: For tracing: caller line of function call + */ +void packet_add_all_do(struct ctx *c, ssize_t l2len, char *p, + const char *func, int line) +{ + const struct ethhdr *eh; + + pcap(p, l2len); + + eh = (struct ethhdr *)p; + + if (memcmp(c->mac_guest, eh->h_source, ETH_ALEN)) { + memcpy(c->mac_guest, eh->h_source, ETH_ALEN); + proto_update_l2_buf(c->mac_guest, NULL); + } + + switch (ntohs(eh->h_proto)) { + case ETH_P_ARP: + case ETH_P_IP: + packet_add_do(pool_tap4, l2len, p, func, line); + break; + case ETH_P_IPV6: + packet_add_do(pool_tap6, l2len, p, func, line); + break; + default: + break; + } +} + /** * tap_sock_reset() - Handle closing or failure of connect AF_UNIX socket * @c: Execution context @@ -946,7 +1001,6 @@ static void tap_sock_reset(struct ctx *c) void tap_handler_passt(struct ctx *c, uint32_t events, const struct timespec *now) { - const struct ethhdr *eh; ssize_t n, rem; char *p; @@ -959,8 +1013,7 @@ redo: p = pkt_buf; rem = 0; - pool_flush(pool_tap4); - pool_flush(pool_tap6); + pool_flush_all(); n = recv(c->fd_tap, p, TAP_BUF_FILL, MSG_DONTWAIT); if (n < 0) { @@ -987,38 +1040,18 @@ redo: /* Complete the partial read above before discarding a malformed * frame, otherwise the stream will be inconsistent. */ - if (l2len < (ssize_t)sizeof(*eh) || + if (l2len < (ssize_t)sizeof(struct ethhdr) || l2len > (ssize_t)ETH_MAX_MTU) goto next; - pcap(p, l2len); - - eh = (struct ethhdr *)p; - - if (memcmp(c->mac_guest, eh->h_source, ETH_ALEN)) { - memcpy(c->mac_guest, eh->h_source, ETH_ALEN); - proto_update_l2_buf(c->mac_guest, NULL); - } - - switch (ntohs(eh->h_proto)) { - case ETH_P_ARP: - case ETH_P_IP: - packet_add(pool_tap4, l2len, p); - break; - case ETH_P_IPV6: - packet_add(pool_tap6, l2len, p); - break; - default: - break; - } + packet_add_all(c, l2len, p); next: p += l2len; n -= l2len; } - tap4_handler(c, pool_tap4, now); - tap6_handler(c, pool_tap6, now); + tap_handler_all(c, now); /* We can't use EPOLLET otherwise. */ if (rem) @@ -1043,35 +1076,18 @@ void tap_handler_pasta(struct ctx *c, uint32_t events, redo: n = 0; - pool_flush(pool_tap4); - pool_flush(pool_tap6); + pool_flush_all(); restart: while ((len = read(c->fd_tap, pkt_buf + n, TAP_BUF_BYTES - n)) > 0) { - const struct ethhdr *eh = (struct ethhdr *)(pkt_buf + n); - if (len < (ssize_t)sizeof(*eh) || len > (ssize_t)ETH_MAX_MTU) { + if (len < (ssize_t)sizeof(struct ethhdr) || + len > (ssize_t)ETH_MAX_MTU) { n += len; continue; } - pcap(pkt_buf + n, len); - if (memcmp(c->mac_guest, eh->h_source, ETH_ALEN)) { - memcpy(c->mac_guest, eh->h_source, ETH_ALEN); - proto_update_l2_buf(c->mac_guest, NULL); - } - - switch (ntohs(eh->h_proto)) { - case ETH_P_ARP: - case ETH_P_IP: - packet_add(pool_tap4, len, pkt_buf + n); - break; - case ETH_P_IPV6: - packet_add(pool_tap6, len, pkt_buf + n); - break; - default: - break; - } + packet_add_all(c, len, pkt_buf + n); if ((n += len) == TAP_BUF_BYTES) break; @@ -1082,8 +1098,7 @@ restart: ret = errno; - tap4_handler(c, pool_tap4, now); - tap6_handler(c, pool_tap6, now); + tap_handler_all(c, now); if (len > 0 || ret == EAGAIN) return; diff --git a/tap.h b/tap.h index 2285a87093f9..3ffb7d6c3a91 100644 --- a/tap.h +++ b/tap.h @@ -70,5 +70,12 @@ void tap_handler_passt(struct ctx *c, uint32_t events, const struct timespec *now); int tap_sock_unix_open(char *sock_path); void tap_sock_init(struct ctx *c); +void pool_flush_all(void); +void tap_handler_all(struct ctx *c, const struct timespec *now); + +void packet_add_all_do(struct ctx *c, ssize_t l2len, char *p, + const char *func, int line); +#define packet_add_all(p, l2len, start) \ + packet_add_all_do(p, l2len, start, __func__, __LINE__) #endif /* TAP_H */-- Stefano