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authorNathan Skrzypczak <nathan.skrzypczak@gmail.com>2021-10-13 12:40:42 +0200
committerDave Wallace <dwallacelf@gmail.com>2021-10-13 23:22:32 +0000
commitcbb4e460c481223282774b37add0bf9fb9e6170a (patch)
treec4d6490e725806088e397bf7bc0daf05e4ab5374 /docs/interfacing/cpp
parent9ad39c026c8a3c945a7003c4aa4f5cb1d4c80160 (diff)
docs: C & C++ apis examples
Type: docs Change-Id: I5b6c388332bdd3a29777d728c3357816c8411ea2 Signed-off-by: Nathan Skrzypczak <nathan.skrzypczak@gmail.com>
Diffstat (limited to 'docs/interfacing/cpp')
-rw-r--r--docs/interfacing/cpp/api_example/Makefile16
-rw-r--r--docs/interfacing/cpp/api_example/api_example.cc283
-rw-r--r--docs/interfacing/cpp/index.rst26
3 files changed, 325 insertions, 0 deletions
diff --git a/docs/interfacing/cpp/api_example/Makefile b/docs/interfacing/cpp/api_example/Makefile
new file mode 100644
index 00000000000..e9f44d3397d
--- /dev/null
+++ b/docs/interfacing/cpp/api_example/Makefile
@@ -0,0 +1,16 @@
+CXXFLAGS:=-std=c++14 -Wextra -Wall -g -O2
+CXXFLAGS+= -Wno-unused-parameter
+#CXXFLAGS+= -O0
+LDFLAGS:=-g
+LDLIBS:=-lvapiclient
+# Customize the lines below if VPP headers and libraries are in non-standard paths
+#CXXFLAGS+= -I/your/vpp/build-root/install-vpp_debug-native/vpp/include
+#LDFLAGS+= -Wl,-rpath,/your/vpp/build-root/install-vpp_debug-native/vpp/lib
+#LDFLAGS+= -L/your/vpp/build-root/install-vpp_debug-native/vpp/lib
+
+all: api_example
+
+clean:
+ $(RM) api_example
+
+.PHONY: all clean
diff --git a/docs/interfacing/cpp/api_example/api_example.cc b/docs/interfacing/cpp/api_example/api_example.cc
new file mode 100644
index 00000000000..cc5a1848e2b
--- /dev/null
+++ b/docs/interfacing/cpp/api_example/api_example.cc
@@ -0,0 +1,283 @@
+//
+// VPP C++ API example
+//
+// The uplink is the 1st interface (sw_if_index is 1) and is set
+// to 10.10.10.10/24 The uplink gateway is 10.10.10.1 The IPsec tunnel is set
+// between 10.10.10.10 and 10.20.20.20 The protected subnet is 192.168.0.0/24
+// VRF 1 is for uplink ingress
+// VRF 2 is IPsec egress (clear -> cipher)
+// VRF 3 is IPsec ingress (cipher -> clear)
+//
+// The following examples must be run with VPP in the following state:
+// ip table add 1 # VRF 1
+// ip table add 2 # VRF 2
+// ip table add 3 # VRF 3
+// loop create # loop0 is used as uplink with sw_if_index=1
+// set int ip table loop0 1 # VRF 1 is ingress
+// set int state loop0 up
+//
+// Then the API will configure VPP similar to this:
+// # configure uplink address
+// set int addr loop0 10.10.10.10/24
+// # create the IP-IP tunnel
+// create ipip tunnel src 10.10.10.1 dst 10.20.20.20 outer-table-id 2
+// # use VRF-3 as IPsec ingress VRF (cipher -> clear)
+// set int ip table ipip0 3
+// set int unnum ipip0 use loop0
+// set int state ipip0 up
+// ipsec sa add 20 spi 200 crypto-key 01234567890123456789012345678901
+// crypto-alg aes-cbc-128 integ-key 01234567890123456789 integ-alg sha1-96
+// use-anti-replay udp-encap
+// ipsec sa add 30 spi 300 crypto-key 01234567890123456789012345678901
+// crypto-alg aes-cbc-128 integ-key 01234567890123456789 integ-alg sha1-96
+// use-anti-replay udp-encap
+// # protect IP-IP with IPsec
+// ipsec tunnel protect ipip0 sa-in 30 sa-out 20
+// # subnet to route through IPsec (clear -> cipher)
+// ip route add table 1 192.168.0.0/24 via ipip0
+// # default route for IPsec packets after encapsulation (clear -> cipher)
+// ip route add table 20.0.0.0/0 via 10.10.10.1 loop0
+// # default route for clear-text packets after decapsulation
+// # (cipher -> clear)
+// ip route add table 30.0.0.0/0 via 10.10.10.1 loop0
+//
+#include <iostream>
+#include <algorithm>
+#include <vapi/vapi.hpp>
+#include <vapi/vpe.api.vapi.hpp>
+DEFINE_VAPI_MSG_IDS_VPE_API_JSON
+#include <vapi/interface.api.vapi.hpp>
+DEFINE_VAPI_MSG_IDS_INTERFACE_API_JSON
+#include <vapi/ip.api.vapi.hpp>
+DEFINE_VAPI_MSG_IDS_IP_API_JSON
+#include <vapi/ipip.api.vapi.hpp>
+DEFINE_VAPI_MSG_IDS_IPIP_API_JSON
+#include <vapi/ipsec.api.vapi.hpp>
+DEFINE_VAPI_MSG_IDS_IPSEC_API_JSON
+
+template <typename MyRequest>
+static auto &
+execute (vapi::Connection &con, MyRequest &req)
+{
+ // send the command to VPP
+ auto err = req.execute ();
+ if (VAPI_OK != err)
+ throw std::runtime_error ("execute()");
+ // active-wait for command result
+ do
+ {
+ err = con.wait_for_response (req);
+ }
+ while (VAPI_EAGAIN == err);
+ if (VAPI_OK != err)
+ throw std::runtime_error ("wait_for_response()");
+ // verify the reply error code
+ auto &rmp = req.get_response ().get_payload ();
+ if (0 != rmp.retval)
+ throw std::runtime_error ("wrong return code");
+ return rmp;
+}
+
+static void
+route_add (vapi::Connection &con, const int vrf, const unsigned char prefix[4],
+ const int plen, const int sw_if_index, const unsigned char nh[4])
+{
+ std::cout << "Adding route..." << std::endl;
+ // ip route add table <vrf> <prefix>/<plen> via <nh> <sw_if_index>
+ vapi::Ip_route_add_del route (con,
+ 1); // cf. src/vnet/ip/ip.api:ip_route_add_del
+ // - we allocate space for 1 path (nh)
+ auto &mp = route.get_request ().get_payload ();
+ mp.is_add = true;
+ mp.is_multipath = false;
+ mp.route.table_id = vrf;
+ mp.route.prefix.address.af = ADDRESS_IP4;
+ std::copy (prefix, prefix + 4, mp.route.prefix.address.un.ip4);
+ mp.route.prefix.len = plen;
+ mp.route.n_paths =
+ 1; // 1 path, must match allocation in route declaration above
+ // cf. src/vnet/fib/fib_types.api:fib_path
+ mp.route.paths[0].sw_if_index = sw_if_index;
+ mp.route.paths[0].proto = FIB_API_PATH_NH_PROTO_IP4;
+ std::copy (nh, nh + 4, mp.route.paths[0].nh.address.ip4);
+ execute (con, route);
+}
+
+static void
+ipsec_sa_add (vapi::Connection &con, const int id, const int spi)
+{
+ std::cout << "Adding SA " << id << "..." << std::endl;
+ // ipsec sa add <id> spi <spi> crypto-key 01234567890123456789012345678901
+ // crypto-alg aes-cbc-128 integ-key 01234567890123456789 integ-alg sha1-96
+ // use-anti-replay udp-encap
+ vapi::Ipsec_sad_entry_add_del_v2 ipsec (
+ con); // cf. src/vnet/ipsec/ipsec.api:ipsec_sad_entry_add_del_v2
+ auto &mp = ipsec.get_request ().get_payload ();
+ mp.is_add = true;
+ // cf. src/vnet/ipsec/ipsec_types.api:ipsec_sad_entry_v2
+ mp.entry.sad_id = id; // user-defined SA id
+ mp.entry.spi = spi;
+ mp.entry.protocol = IPSEC_API_PROTO_ESP;
+ mp.entry.crypto_algorithm = IPSEC_API_CRYPTO_ALG_AES_CBC_128;
+ const char key[] =
+ "\x01\x23\x45\x67\x89\x01\x23\x45\x67\x89\x01\x23\x45\x67\x89\x01";
+ // cf. src/vnet/ipsec/ipsec_types.api:key
+ mp.entry.crypto_key.length = sizeof (key) - 1;
+ std::copy (key, key + sizeof (key) - 1, mp.entry.crypto_key.data);
+ mp.entry.integrity_algorithm = IPSEC_API_INTEG_ALG_SHA1_96;
+ mp.entry.integrity_key.length = sizeof (key) - 1;
+ std::copy (key, key + sizeof (key) - 1, mp.entry.integrity_key.data);
+ mp.entry.flags = (vapi_enum_ipsec_sad_flags) (
+ IPSEC_API_SAD_FLAG_USE_ANTI_REPLAY | IPSEC_API_SAD_FLAG_UDP_ENCAP);
+ mp.entry.udp_src_port = 4500;
+ mp.entry.udp_dst_port = 4500;
+ execute (con, ipsec);
+}
+
+int
+main ()
+{
+ // Connect to VPP: client name, API prefix, max outstanding request, response
+ // queue size
+ std::cout << "Connecting to VPP..." << std::endl;
+ vapi::Connection con;
+ auto err = con.connect ("example_client", nullptr, 32, 32);
+ if (VAPI_OK != err)
+ throw std::runtime_error ("connection to VPP failed");
+
+ try
+ {
+
+ std::cout << "Configuring address..." << std::endl;
+ {
+ // set int addr <uplink> 10.10.10.10/24
+ vapi::Sw_interface_add_del_address addr (
+ con); // cf. src/vnet/interface.api:sw_interface_add_del_address
+ auto &mp = addr.get_request ().get_payload ();
+ mp.sw_if_index = 1; // uplink
+ mp.is_add = true;
+ mp.prefix.address.af = ADDRESS_IP4;
+ const char ip[] = { 0x0a, 0x0a, 0x0a, 0x0a }; // 10.10.10.10
+ std::copy (ip, ip + 4, mp.prefix.address.un.ip4);
+ mp.prefix.len = 24;
+ execute (con, addr);
+ }
+
+ std::cout << "Creating IP-IP tunnel..." << std::endl;
+ unsigned ipip_sw_if_index;
+ {
+ // create ipip tunnel src 10.10.10.1 dst 10.20.20.20 outer-table-id 2
+ vapi::Ipip_add_tunnel ipip (
+ con); // cf. src/vnet/ipip/ipip.api:ipip_add_tunnel
+ auto &mp = ipip.get_request ().get_payload ();
+ mp.tunnel.instance = ~0;
+ mp.tunnel.src.af = ADDRESS_IP4;
+ const char src[] = { 0x0a, 0x0a, 0x0a, 0x0a }; // 10.10.10.10
+ std::copy (src, src + 4, mp.tunnel.src.un.ip4);
+ mp.tunnel.dst.af = ADDRESS_IP4;
+ const char dst[] = { 0x0a, 0x14, 0x14, 0x14 }; // 10.20.20.20
+ std::copy (dst, dst + 4, mp.tunnel.dst.un.ip4);
+ mp.tunnel.table_id =
+ 2; // VRF 2 - encapsulated (ciphered) packets should be lookup'ed in
+ // VRF 2 to determine path
+ auto &rmp = execute (con, ipip);
+ ipip_sw_if_index =
+ rmp.sw_if_index; // save ipip tunnel index for later use
+ }
+
+ std::cout << "Moving IP-IP tunnel to VRF 3..." << std::endl;
+ {
+ // set int ip table ipip0 3
+ vapi::Sw_interface_set_table table (
+ con); // cf. src/vnet/interface.api:sw_interface_set_table
+ auto &mp = table.get_request ().get_payload ();
+ mp.sw_if_index = ipip_sw_if_index;
+ mp.vrf_id = 3; // VRF 3 - decapsulated (deciphered) packets should be
+ // lookup'ed in VRF 3 to determine path
+ execute (con, table);
+ }
+
+ std::cout << "Configuring IP-IP tunnel as unnumbered..." << std::endl;
+ {
+ // set int unnum ipip0 use <uplink>
+ vapi::Sw_interface_set_unnumbered unnum (
+ con); // cf. src/vnet/interface.api:sw_interface_set_unnumbered
+ auto &mp = unnum.get_request ().get_payload ();
+ mp.sw_if_index = 1; // uplink
+ mp.unnumbered_sw_if_index = ipip_sw_if_index;
+ execute (con, unnum);
+ }
+
+ std::cout << "Setting IP-IP tunnel up..." << std::endl;
+ {
+ // set int state ipip0 up
+ vapi::Sw_interface_set_flags flags (
+ con); // cf. src/vnet/interface.api:sw_interface_set_flags
+ auto &mp = flags.get_request ().get_payload ();
+ mp.sw_if_index = ipip_sw_if_index;
+ mp.flags = IF_STATUS_API_FLAG_ADMIN_UP;
+ execute (con, flags);
+ }
+
+ // ipsec sa add 20 spi 200 crypto-key 01234567890123456789012345678901
+ // crypto-alg aes-cbc-128 integ-key 01234567890123456789 integ-alg
+ // sha1-96 use-anti-replay udp-encap
+ ipsec_sa_add (con, 20, 200);
+
+ // ipsec sa add 30 spi 300 crypto-key 01234567890123456789012345678901
+ // crypto-alg aes-cbc-128 integ-key 01234567890123456789 integ-alg
+ // sha1-96 use-anti-replay udp-encap
+ ipsec_sa_add (con, 30, 300);
+
+ std::cout << "Protecting IP-IP tunnel..." << std::endl;
+ {
+ // ipsec tunnel protect ipip0 sa-in 30 sa-out 20
+ vapi::Ipsec_tunnel_protect_update tun (
+ con, 1); // cf. src/vnet/ipsec/ipsec.api:ipsec_tunnel_protect_update
+ // - we allocate space for 1 sa_in
+ auto &mp = tun.get_request ().get_payload ();
+ // cf. src/vnet/ipsec/ipsec.api:ipsec_tunnel_protect
+ mp.tunnel.sw_if_index = ipip_sw_if_index;
+ mp.tunnel.sa_out = 20;
+ mp.tunnel.n_sa_in =
+ 1; // 1 SA, must match allocation in declaration above
+ mp.tunnel.sa_in[0] = 30;
+ execute (con, tun);
+ }
+
+ // add route for clear-text packets to be encrypted
+ // ip route add table 1 192.168.0.0/24 via ipip0
+ route_add (con,
+ 1, // VRF 1
+ (const unsigned char[]){ 192, 168, 0, 0 },
+ 24, // 192.168.0.0/24
+ ipip_sw_if_index, // ipip0
+ (const unsigned char[]){}); // 0
+
+ // add default route for encrypted packets (clear -> ciphered)
+ // ip route add table 2 0.0.0.0/0 via 10.10.10.1 <uplink>
+ route_add (con,
+ 2, // VRF 2
+ (const unsigned char[]){}, 0, // 0.0.0.0/0
+ 1, // <uplink>
+ (const unsigned char[]){ 10, 10, 10, 1 }); // 10.0.0.1
+
+ // add default route for decrypted packets (ciphered -> clear)
+ // ip route add table 3 0.0.0.0/0 via 10.10.10.1 <uplink>
+ route_add (con,
+ 3, // VRF 3
+ (const unsigned char[]){}, 0, // 0.0.0.0/0
+ 1, // <uplink>
+ (const unsigned char[]){ 10, 10, 10, 1 }); // 10.0.0.1
+ }
+ catch (...)
+ {
+ std::cerr << "Failure" << std::endl;
+ con.disconnect ();
+ return 1;
+ }
+
+ con.disconnect ();
+ std::cerr << "Success" << std::endl;
+ return 0;
+}
diff --git a/docs/interfacing/cpp/index.rst b/docs/interfacing/cpp/index.rst
new file mode 100644
index 00000000000..8351e9c504a
--- /dev/null
+++ b/docs/interfacing/cpp/index.rst
@@ -0,0 +1,26 @@
+.. _cppvpp:
+
+==============
+C++ api client
+==============
+
+This describes how to write a C++ api client connecting to VPP's binary API.
+
+Connecting to VPP is done with :
+
+::
+
+ auto err = con.connect("example_client", nullptr, 32, 32);
+
+
+You can specify the path to the api socket/shared memory you want to connect to
+with the second parameter (set to ``nullptr``, meaning default)
+
+.. literalinclude:: ./api_example/api_example.cc
+ :language: cpp
+
+To build this you could use the following makefile
+
+.. literalinclude:: ./api_example/Makefile
+ :language: makefile
+