We have upcoming use cases where it's useful to create new bound socket
based on information from the flow table. Add flowside_sock_l4() to do
this for either PIF_HOST or PIF_SPLICE sockets.
Signed-off-by: David Gibson <david(a)gibson.dropbear.id.au>
---
flow.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
flow.h | 3 ++
util.c | 6 ++--
util.h | 3 ++
4 files changed, 101 insertions(+), 3 deletions(-)
diff --git a/flow.c b/flow.c
index 6f09781a..2d0a8a32 100644
--- a/flow.c
+++ b/flow.c
@@ -5,9 +5,11 @@
* Tracking for logical "flows" of packets.
*/
+#include <errno.h>
#include <stdint.h>
#include <stdio.h>
#include <unistd.h>
+#include <sched.h>
#include <string.h>
#include "util.h"
@@ -143,6 +145,96 @@ static void flowside_from_af(struct flowside *fside, sa_family_t af,
fside->eport = eport;
}
+/**
+ * struct flowside_sock_args - Parameters for flowside_sock_splice()
+ * @c: Execution context
+ * @fd: Filled in with new socket fd
+ * @err: Filled in with errno if something failed
+ * @type: Socket epoll type
+ * @sa: Socket address
+ * @sl: Length of @sa
+ * @data: epoll reference data
+ */
+struct flowside_sock_args {
+ const struct ctx *c;
+ int fd;
+ int err;
+ enum epoll_type type;
+ const struct sockaddr *sa;
+ socklen_t sl;
+ const char *path;
+ uint32_t data;
+};
+
+/** flowside_sock_splice() - Create and bind socket for PIF_SPLICE based on flowside
+ * @arg: Argument as a struct flowside_sock_args
+ *
+ * Return: 0
+ */
+static int flowside_sock_splice(void *arg)
+{
+ struct flowside_sock_args *a = arg;
+
+ ns_enter(a->c);
+
+ a->fd = sock_l4_sa(a->c, a->type, a->sa, a->sl, NULL,
+ a->sa->sa_family == AF_INET6, a->data);
+ a->err = errno;
+
+ return 0;
+}
+
+/** flowside_sock_l4() - Create and bind socket based on flowside
+ * @c: Execution context
+ * @type: Socket epoll type
+ * @pif: Interface for this socket
+ * @tgt: Target flowside
+ * @data: epoll reference portion for protocol handlers
+ *
+ * Return: socket fd of protocol @proto bound to the forwarding address and port
+ * from @tgt (if specified).
+ */
+/* cppcheck-suppress unusedFunction */
+int flowside_sock_l4(const struct ctx *c, enum epoll_type type, uint8_t pif,
+ const struct flowside *tgt, uint32_t data)
+{
+ const char *ifname = NULL;
+ union sockaddr_inany sa;
+ socklen_t sl;
+
+ ASSERT(pif_is_socket(pif));
+
+ pif_sockaddr(c, &sa, &sl, pif, &tgt->faddr, tgt->fport);
+
+ switch (pif) {
+ case PIF_HOST:
+ if (inany_is_loopback(&tgt->faddr))
+ ifname = NULL;
+ else if (sa.sa_family == AF_INET)
+ ifname = c->ip4.ifname_out;
+ else if (sa.sa_family == AF_INET6)
+ ifname = c->ip6.ifname_out;
+
+ return sock_l4_sa(c, type, &sa, sl, ifname,
+ sa.sa_family == AF_INET6, data);
+
+ case PIF_SPLICE: {
+ struct flowside_sock_args args = {
+ .c = c, .type = type,
+ .sa = &sa.sa, .sl = sl, .data = data,
+ };
+ NS_CALL(flowside_sock_splice, &args);
+ errno = args.err;
+ return args.fd;
+ }
+
+ default:
+ /* If we add new socket pifs, they'll need to be implemented
+ * here */
+ ASSERT(0);
+ }
+}
+
/** flow_log_ - Log flow-related message
* @f: flow the message is related to
* @pri: Log priority
diff --git a/flow.h b/flow.h
index c3a15ca6..e27f99be 100644
--- a/flow.h
+++ b/flow.h
@@ -164,6 +164,9 @@ static inline bool flowside_eq(const struct flowside *left,
left->fport == right->fport;
}
+int flowside_sock_l4(const struct ctx *c, enum epoll_type type, uint8_t pif,
+ const struct flowside *tgt, uint32_t data);
+
/**
* struct flow_common - Common fields for packet flows
* @state: State of the flow table entry
diff --git a/util.c b/util.c
index 9a73fbb9..f2994a79 100644
--- a/util.c
+++ b/util.c
@@ -44,9 +44,9 @@
*
* Return: newly created socket, negative error code on failure
*/
-static int sock_l4_sa(const struct ctx *c, enum epoll_type type,
- const void *sa, socklen_t sl,
- const char *ifname, bool v6only, uint32_t data)
+int sock_l4_sa(const struct ctx *c, enum epoll_type type,
+ const void *sa, socklen_t sl,
+ const char *ifname, bool v6only, uint32_t data)
{
sa_family_t af = ((const struct sockaddr *)sa)->sa_family;
union epoll_ref ref = { .type = type, .data = data };
diff --git a/util.h b/util.h
index d0150396..f2e4f8cf 100644
--- a/util.h
+++ b/util.h
@@ -144,6 +144,9 @@ struct ctx;
/* cppcheck-suppress funcArgNamesDifferent */
__attribute__ ((weak)) int ffsl(long int i) { return __builtin_ffsl(i); }
+int sock_l4_sa(const struct ctx *c, enum epoll_type type,
+ const void *sa, socklen_t sl,
+ const char *ifname, bool v6only, uint32_t data);
int sock_l4(const struct ctx *c, sa_family_t af, enum epoll_type type,
const void *bind_addr, const char *ifname, uint16_t port,
uint32_t data);
--
2.45.2