From 983695fa676568fc0fe5ddd995c7267aabc24632 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Fri, 7 Jun 2019 01:48:57 +0200 Subject: bpf: fix unconnected udp hooks Intention of cgroup bind/connect/sendmsg BPF hooks is to act transparently to applications as also stated in original motivation in 7828f20e3779 ("Merge branch 'bpf-cgroup-bind-connect'"). When recently integrating the latter two hooks into Cilium to enable host based load-balancing with Kubernetes, I ran into the issue that pods couldn't start up as DNS got broken. Kubernetes typically sets up DNS as a service and is thus subject to load-balancing. Upon further debugging, it turns out that the cgroupv2 sendmsg BPF hooks API is currently insufficient and thus not usable as-is for standard applications shipped with most distros. To break down the issue we ran into with a simple example: # cat /etc/resolv.conf nameserver 147.75.207.207 nameserver 147.75.207.208 For the purpose of a simple test, we set up above IPs as service IPs and transparently redirect traffic to a different DNS backend server for that node: # cilium service list ID Frontend Backend 1 147.75.207.207:53 1 => 8.8.8.8:53 2 147.75.207.208:53 1 => 8.8.8.8:53 The attached BPF program is basically selecting one of the backends if the service IP/port matches on the cgroup hook. DNS breaks here, because the hooks are not transparent enough to applications which have built-in msg_name address checks: # nslookup 1.1.1.1 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.207#53 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.208#53 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.207#53 [...] ;; connection timed out; no servers could be reached # dig 1.1.1.1 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.207#53 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.208#53 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.207#53 [...] ; <<>> DiG 9.11.3-1ubuntu1.7-Ubuntu <<>> 1.1.1.1 ;; global options: +cmd ;; connection timed out; no servers could be reached For comparison, if none of the service IPs is used, and we tell nslookup to use 8.8.8.8 directly it works just fine, of course: # nslookup 1.1.1.1 8.8.8.8 1.1.1.1.in-addr.arpa name = one.one.one.one. In order to fix this and thus act more transparent to the application, this needs reverse translation on recvmsg() side. A minimal fix for this API is to add similar recvmsg() hooks behind the BPF cgroups static key such that the program can track state and replace the current sockaddr_in{,6} with the original service IP. From BPF side, this basically tracks the service tuple plus socket cookie in an LRU map where the reverse NAT can then be retrieved via map value as one example. Side-note: the BPF cgroups static key should be converted to a per-hook static key in future. Same example after this fix: # cilium service list ID Frontend Backend 1 147.75.207.207:53 1 => 8.8.8.8:53 2 147.75.207.208:53 1 => 8.8.8.8:53 Lookups work fine now: # nslookup 1.1.1.1 1.1.1.1.in-addr.arpa name = one.one.one.one. Authoritative answers can be found from: # dig 1.1.1.1 ; <<>> DiG 9.11.3-1ubuntu1.7-Ubuntu <<>> 1.1.1.1 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 51550 ;; flags: qr rd ra ad; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 512 ;; QUESTION SECTION: ;1.1.1.1. IN A ;; AUTHORITY SECTION: . 23426 IN SOA a.root-servers.net. nstld.verisign-grs.com. 2019052001 1800 900 604800 86400 ;; Query time: 17 msec ;; SERVER: 147.75.207.207#53(147.75.207.207) ;; WHEN: Tue May 21 12:59:38 UTC 2019 ;; MSG SIZE rcvd: 111 And from an actual packet level it shows that we're using the back end server when talking via 147.75.207.20{7,8} front end: # tcpdump -i any udp [...] 12:59:52.698732 IP foo.42011 > google-public-dns-a.google.com.domain: 18803+ PTR? 1.1.1.1.in-addr.arpa. (38) 12:59:52.698735 IP foo.42011 > google-public-dns-a.google.com.domain: 18803+ PTR? 1.1.1.1.in-addr.arpa. (38) 12:59:52.701208 IP google-public-dns-a.google.com.domain > foo.42011: 18803 1/0/0 PTR one.one.one.one. (67) 12:59:52.701208 IP google-public-dns-a.google.com.domain > foo.42011: 18803 1/0/0 PTR one.one.one.one. (67) [...] In order to be flexible and to have same semantics as in sendmsg BPF programs, we only allow return codes in [1,1] range. In the sendmsg case the program is called if msg->msg_name is present which can be the case in both, connected and unconnected UDP. The former only relies on the sockaddr_in{,6} passed via connect(2) if passed msg->msg_name was NULL. Therefore, on recvmsg side, we act in similar way to call into the BPF program whenever a non-NULL msg->msg_name was passed independent of sk->sk_state being TCP_ESTABLISHED or not. Note that for TCP case, the msg->msg_name is ignored in the regular recvmsg path and therefore not relevant. For the case of ip{,v6}_recv_error() paths, picked up via MSG_ERRQUEUE, the hook is not called. This is intentional as it aligns with the same semantics as in case of TCP cgroup BPF hooks right now. This might be better addressed in future through a different bpf_attach_type such that this case can be distinguished from the regular recvmsg paths, for example. Fixes: 1cedee13d25a ("bpf: Hooks for sys_sendmsg") Signed-off-by: Daniel Borkmann Acked-by: Andrey Ignatov Acked-by: Martin KaFai Lau Acked-by: Martynas Pumputis Signed-off-by: Alexei Starovoitov --- include/linux/bpf-cgroup.h | 8 ++++++++ include/uapi/linux/bpf.h | 2 ++ kernel/bpf/syscall.c | 8 ++++++++ kernel/bpf/verifier.c | 12 ++++++++---- net/core/filter.c | 2 ++ net/ipv4/udp.c | 4 ++++ net/ipv6/udp.c | 4 ++++ 7 files changed, 36 insertions(+), 4 deletions(-) diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h index cb3c6b3b89c8..a7f7a98ec39d 100644 --- a/include/linux/bpf-cgroup.h +++ b/include/linux/bpf-cgroup.h @@ -238,6 +238,12 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, #define BPF_CGROUP_RUN_PROG_UDP6_SENDMSG_LOCK(sk, uaddr, t_ctx) \ BPF_CGROUP_RUN_SA_PROG_LOCK(sk, uaddr, BPF_CGROUP_UDP6_SENDMSG, t_ctx) +#define BPF_CGROUP_RUN_PROG_UDP4_RECVMSG_LOCK(sk, uaddr) \ + BPF_CGROUP_RUN_SA_PROG_LOCK(sk, uaddr, BPF_CGROUP_UDP4_RECVMSG, NULL) + +#define BPF_CGROUP_RUN_PROG_UDP6_RECVMSG_LOCK(sk, uaddr) \ + BPF_CGROUP_RUN_SA_PROG_LOCK(sk, uaddr, BPF_CGROUP_UDP6_RECVMSG, NULL) + #define BPF_CGROUP_RUN_PROG_SOCK_OPS(sock_ops) \ ({ \ int __ret = 0; \ @@ -339,6 +345,8 @@ static inline int bpf_percpu_cgroup_storage_update(struct bpf_map *map, #define BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr) ({ 0; }) #define BPF_CGROUP_RUN_PROG_UDP4_SENDMSG_LOCK(sk, uaddr, t_ctx) ({ 0; }) #define BPF_CGROUP_RUN_PROG_UDP6_SENDMSG_LOCK(sk, uaddr, t_ctx) ({ 0; }) +#define BPF_CGROUP_RUN_PROG_UDP4_RECVMSG_LOCK(sk, uaddr) ({ 0; }) +#define BPF_CGROUP_RUN_PROG_UDP6_RECVMSG_LOCK(sk, uaddr) ({ 0; }) #define BPF_CGROUP_RUN_PROG_SOCK_OPS(sock_ops) ({ 0; }) #define BPF_CGROUP_RUN_PROG_DEVICE_CGROUP(type,major,minor,access) ({ 0; }) #define BPF_CGROUP_RUN_PROG_SYSCTL(head,table,write,buf,count,pos,nbuf) ({ 0; }) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 63e0cf66f01a..e4114a7e4451 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -192,6 +192,8 @@ enum bpf_attach_type { BPF_LIRC_MODE2, BPF_FLOW_DISSECTOR, BPF_CGROUP_SYSCTL, + BPF_CGROUP_UDP4_RECVMSG, + BPF_CGROUP_UDP6_RECVMSG, __MAX_BPF_ATTACH_TYPE }; diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index cb5440b02e82..e8ba3a153691 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1581,6 +1581,8 @@ bpf_prog_load_check_attach_type(enum bpf_prog_type prog_type, case BPF_CGROUP_INET6_CONNECT: case BPF_CGROUP_UDP4_SENDMSG: case BPF_CGROUP_UDP6_SENDMSG: + case BPF_CGROUP_UDP4_RECVMSG: + case BPF_CGROUP_UDP6_RECVMSG: return 0; default: return -EINVAL; @@ -1875,6 +1877,8 @@ static int bpf_prog_attach(const union bpf_attr *attr) case BPF_CGROUP_INET6_CONNECT: case BPF_CGROUP_UDP4_SENDMSG: case BPF_CGROUP_UDP6_SENDMSG: + case BPF_CGROUP_UDP4_RECVMSG: + case BPF_CGROUP_UDP6_RECVMSG: ptype = BPF_PROG_TYPE_CGROUP_SOCK_ADDR; break; case BPF_CGROUP_SOCK_OPS: @@ -1960,6 +1964,8 @@ static int bpf_prog_detach(const union bpf_attr *attr) case BPF_CGROUP_INET6_CONNECT: case BPF_CGROUP_UDP4_SENDMSG: case BPF_CGROUP_UDP6_SENDMSG: + case BPF_CGROUP_UDP4_RECVMSG: + case BPF_CGROUP_UDP6_RECVMSG: ptype = BPF_PROG_TYPE_CGROUP_SOCK_ADDR; break; case BPF_CGROUP_SOCK_OPS: @@ -2011,6 +2017,8 @@ static int bpf_prog_query(const union bpf_attr *attr, case BPF_CGROUP_INET6_CONNECT: case BPF_CGROUP_UDP4_SENDMSG: case BPF_CGROUP_UDP6_SENDMSG: + case BPF_CGROUP_UDP4_RECVMSG: + case BPF_CGROUP_UDP6_RECVMSG: case BPF_CGROUP_SOCK_OPS: case BPF_CGROUP_DEVICE: case BPF_CGROUP_SYSCTL: diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 95f9354495ad..d2c8a6677ac4 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5361,9 +5361,12 @@ static int check_return_code(struct bpf_verifier_env *env) struct tnum range = tnum_range(0, 1); switch (env->prog->type) { + case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: + if (env->prog->expected_attach_type == BPF_CGROUP_UDP4_RECVMSG || + env->prog->expected_attach_type == BPF_CGROUP_UDP6_RECVMSG) + range = tnum_range(1, 1); case BPF_PROG_TYPE_CGROUP_SKB: case BPF_PROG_TYPE_CGROUP_SOCK: - case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: case BPF_PROG_TYPE_SOCK_OPS: case BPF_PROG_TYPE_CGROUP_DEVICE: case BPF_PROG_TYPE_CGROUP_SYSCTL: @@ -5380,16 +5383,17 @@ static int check_return_code(struct bpf_verifier_env *env) } if (!tnum_in(range, reg->var_off)) { + char tn_buf[48]; + verbose(env, "At program exit the register R0 "); if (!tnum_is_unknown(reg->var_off)) { - char tn_buf[48]; - tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off); verbose(env, "has value %s", tn_buf); } else { verbose(env, "has unknown scalar value"); } - verbose(env, " should have been 0 or 1\n"); + tnum_strn(tn_buf, sizeof(tn_buf), range); + verbose(env, " should have been in %s\n", tn_buf); return -EINVAL; } return 0; diff --git a/net/core/filter.c b/net/core/filter.c index fdcc504d2dec..2814d785c110 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -6748,6 +6748,7 @@ static bool sock_addr_is_valid_access(int off, int size, case BPF_CGROUP_INET4_BIND: case BPF_CGROUP_INET4_CONNECT: case BPF_CGROUP_UDP4_SENDMSG: + case BPF_CGROUP_UDP4_RECVMSG: break; default: return false; @@ -6758,6 +6759,7 @@ static bool sock_addr_is_valid_access(int off, int size, case BPF_CGROUP_INET6_BIND: case BPF_CGROUP_INET6_CONNECT: case BPF_CGROUP_UDP6_SENDMSG: + case BPF_CGROUP_UDP6_RECVMSG: break; default: return false; diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 85db0e3d7f3f..2d862823cbb7 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1783,6 +1783,10 @@ try_again: sin->sin_addr.s_addr = ip_hdr(skb)->saddr; memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); *addr_len = sizeof(*sin); + + if (cgroup_bpf_enabled) + BPF_CGROUP_RUN_PROG_UDP4_RECVMSG_LOCK(sk, + (struct sockaddr *)sin); } if (udp_sk(sk)->gro_enabled) diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 4e52c37bb836..15570d7b9b61 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -369,6 +369,10 @@ try_again: inet6_iif(skb)); } *addr_len = sizeof(*sin6); + + if (cgroup_bpf_enabled) + BPF_CGROUP_RUN_PROG_UDP6_RECVMSG_LOCK(sk, + (struct sockaddr *)sin6); } if (udp_sk(sk)->gro_enabled) -- cgit v1.2.3 From 3dbc6adac1f3b83fd4c39899c747da7b417e3ffc Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Fri, 7 Jun 2019 01:48:58 +0200 Subject: bpf: sync tooling uapi header Sync BPF uapi header in order to pull in BPF_CGROUP_UDP{4,6}_RECVMSG attach types. This is done and preferred as an extra patch in order to ease sync of libbpf. Signed-off-by: Daniel Borkmann Acked-by: Andrey Ignatov Acked-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov --- tools/include/uapi/linux/bpf.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 63e0cf66f01a..e4114a7e4451 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -192,6 +192,8 @@ enum bpf_attach_type { BPF_LIRC_MODE2, BPF_FLOW_DISSECTOR, BPF_CGROUP_SYSCTL, + BPF_CGROUP_UDP4_RECVMSG, + BPF_CGROUP_UDP6_RECVMSG, __MAX_BPF_ATTACH_TYPE }; -- cgit v1.2.3 From 9bb59ac1f6c362f14b58187bc56e737780c52c19 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Fri, 7 Jun 2019 01:48:59 +0200 Subject: bpf, libbpf: enable recvmsg attach types Another trivial patch to libbpf in order to enable identifying and attaching programs to BPF_CGROUP_UDP{4,6}_RECVMSG by section name. Signed-off-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/libbpf.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 5d046cc7b207..151f7ac1882e 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -3210,6 +3210,10 @@ static const struct { BPF_CGROUP_UDP4_SENDMSG), BPF_EAPROG_SEC("cgroup/sendmsg6", BPF_PROG_TYPE_CGROUP_SOCK_ADDR, BPF_CGROUP_UDP6_SENDMSG), + BPF_EAPROG_SEC("cgroup/recvmsg4", BPF_PROG_TYPE_CGROUP_SOCK_ADDR, + BPF_CGROUP_UDP4_RECVMSG), + BPF_EAPROG_SEC("cgroup/recvmsg6", BPF_PROG_TYPE_CGROUP_SOCK_ADDR, + BPF_CGROUP_UDP6_RECVMSG), BPF_EAPROG_SEC("cgroup/sysctl", BPF_PROG_TYPE_CGROUP_SYSCTL, BPF_CGROUP_SYSCTL), }; -- cgit v1.2.3 From 000aa1250d572171807b47fb9cd3fadfbcc36ad0 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Fri, 7 Jun 2019 01:49:00 +0200 Subject: bpf, bpftool: enable recvmsg attach types Trivial patch to bpftool in order to complete enabling attaching programs to BPF_CGROUP_UDP{4,6}_RECVMSG. Signed-off-by: Daniel Borkmann Acked-by: Andrey Ignatov Acked-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov --- tools/bpf/bpftool/Documentation/bpftool-cgroup.rst | 6 +++++- tools/bpf/bpftool/Documentation/bpftool-prog.rst | 2 +- tools/bpf/bpftool/bash-completion/bpftool | 5 +++-- tools/bpf/bpftool/cgroup.c | 5 ++++- tools/bpf/bpftool/prog.c | 3 ++- 5 files changed, 15 insertions(+), 6 deletions(-) diff --git a/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst b/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst index ac26876389c2..e744b3e4e56a 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst @@ -29,7 +29,7 @@ CGROUP COMMANDS | *PROG* := { **id** *PROG_ID* | **pinned** *FILE* | **tag** *PROG_TAG* } | *ATTACH_TYPE* := { **ingress** | **egress** | **sock_create** | **sock_ops** | **device** | | **bind4** | **bind6** | **post_bind4** | **post_bind6** | **connect4** | **connect6** | -| **sendmsg4** | **sendmsg6** | **sysctl** } +| **sendmsg4** | **sendmsg6** | **recvmsg4** | **recvmsg6** | **sysctl** } | *ATTACH_FLAGS* := { **multi** | **override** } DESCRIPTION @@ -86,6 +86,10 @@ DESCRIPTION unconnected udp4 socket (since 4.18); **sendmsg6** call to sendto(2), sendmsg(2), sendmmsg(2) for an unconnected udp6 socket (since 4.18); + **recvmsg4** call to recvfrom(2), recvmsg(2), recvmmsg(2) for + an unconnected udp4 socket (since 5.2); + **recvmsg6** call to recvfrom(2), recvmsg(2), recvmmsg(2) for + an unconnected udp6 socket (since 5.2); **sysctl** sysctl access (since 5.2). **bpftool cgroup detach** *CGROUP* *ATTACH_TYPE* *PROG* diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst b/tools/bpf/bpftool/Documentation/bpftool-prog.rst index e8118544d118..018ecef8dc13 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst @@ -40,7 +40,7 @@ PROG COMMANDS | **lwt_seg6local** | **sockops** | **sk_skb** | **sk_msg** | **lirc_mode2** | | **cgroup/bind4** | **cgroup/bind6** | **cgroup/post_bind4** | **cgroup/post_bind6** | | **cgroup/connect4** | **cgroup/connect6** | **cgroup/sendmsg4** | **cgroup/sendmsg6** | -| **cgroup/sysctl** +| **cgroup/recvmsg4** | **cgroup/recvmsg6** | **cgroup/sysctl** | } | *ATTACH_TYPE* := { | **msg_verdict** | **stream_verdict** | **stream_parser** | **flow_dissector** diff --git a/tools/bpf/bpftool/bash-completion/bpftool b/tools/bpf/bpftool/bash-completion/bpftool index 50e402a5a9c8..4300adf6e5ab 100644 --- a/tools/bpf/bpftool/bash-completion/bpftool +++ b/tools/bpf/bpftool/bash-completion/bpftool @@ -371,6 +371,7 @@ _bpftool() lirc_mode2 cgroup/bind4 cgroup/bind6 \ cgroup/connect4 cgroup/connect6 \ cgroup/sendmsg4 cgroup/sendmsg6 \ + cgroup/recvmsg4 cgroup/recvmsg6 \ cgroup/post_bind4 cgroup/post_bind6 \ cgroup/sysctl" -- \ "$cur" ) ) @@ -666,7 +667,7 @@ _bpftool() attach|detach) local ATTACH_TYPES='ingress egress sock_create sock_ops \ device bind4 bind6 post_bind4 post_bind6 connect4 \ - connect6 sendmsg4 sendmsg6 sysctl' + connect6 sendmsg4 sendmsg6 recvmsg4 recvmsg6 sysctl' local ATTACH_FLAGS='multi override' local PROG_TYPE='id pinned tag' case $prev in @@ -676,7 +677,7 @@ _bpftool() ;; ingress|egress|sock_create|sock_ops|device|bind4|bind6|\ post_bind4|post_bind6|connect4|connect6|sendmsg4|\ - sendmsg6|sysctl) + sendmsg6|recvmsg4|recvmsg6|sysctl) COMPREPLY=( $( compgen -W "$PROG_TYPE" -- \ "$cur" ) ) return 0 diff --git a/tools/bpf/bpftool/cgroup.c b/tools/bpf/bpftool/cgroup.c index 7e22f115c8c1..73ec8ea33fb4 100644 --- a/tools/bpf/bpftool/cgroup.c +++ b/tools/bpf/bpftool/cgroup.c @@ -25,7 +25,8 @@ " ATTACH_TYPE := { ingress | egress | sock_create |\n" \ " sock_ops | device | bind4 | bind6 |\n" \ " post_bind4 | post_bind6 | connect4 |\n" \ - " connect6 | sendmsg4 | sendmsg6 | sysctl }" + " connect6 | sendmsg4 | sendmsg6 |\n" \ + " recvmsg4 | recvmsg6 | sysctl }" static const char * const attach_type_strings[] = { [BPF_CGROUP_INET_INGRESS] = "ingress", @@ -42,6 +43,8 @@ static const char * const attach_type_strings[] = { [BPF_CGROUP_UDP4_SENDMSG] = "sendmsg4", [BPF_CGROUP_UDP6_SENDMSG] = "sendmsg6", [BPF_CGROUP_SYSCTL] = "sysctl", + [BPF_CGROUP_UDP4_RECVMSG] = "recvmsg4", + [BPF_CGROUP_UDP6_RECVMSG] = "recvmsg6", [__MAX_BPF_ATTACH_TYPE] = NULL, }; diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index 26336bad0442..7a4e21a31523 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -1063,7 +1063,8 @@ static int do_help(int argc, char **argv) " sk_reuseport | flow_dissector | cgroup/sysctl |\n" " cgroup/bind4 | cgroup/bind6 | cgroup/post_bind4 |\n" " cgroup/post_bind6 | cgroup/connect4 | cgroup/connect6 |\n" - " cgroup/sendmsg4 | cgroup/sendmsg6 }\n" + " cgroup/sendmsg4 | cgroup/sendmsg6 | cgroup/recvmsg4 |\n" + " cgroup/recvmsg6 }\n" " ATTACH_TYPE := { msg_verdict | stream_verdict | stream_parser |\n" " flow_dissector }\n" " " HELP_SPEC_OPTIONS "\n" -- cgit v1.2.3 From 1812291e7661673cc29f52b38d9cc39540dee08e Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Fri, 7 Jun 2019 01:49:01 +0200 Subject: bpf: more msg_name rewrite tests to test_sock_addr Extend test_sock_addr for recvmsg test cases, bigger parts of the sendmsg code can be reused for this. Below are the strace view of the recvmsg rewrites; the sendmsg side does not have a BPF prog connected to it for the context of this test: IPv4 test case: [pid 4846] bpf(BPF_PROG_ATTACH, {target_fd=3, attach_bpf_fd=4, attach_type=0x13 /* BPF_??? */, attach_flags=BPF_F_ALLOW_OVERRIDE}, 112) = 0 [pid 4846] socket(AF_INET, SOCK_DGRAM, IPPROTO_IP) = 5 [pid 4846] bind(5, {sa_family=AF_INET, sin_port=htons(4444), sin_addr=inet_addr("127.0.0.1")}, 128) = 0 [pid 4846] socket(AF_INET, SOCK_DGRAM, IPPROTO_IP) = 6 [pid 4846] sendmsg(6, {msg_name={sa_family=AF_INET, sin_port=htons(4444), sin_addr=inet_addr("127.0.0.1")}, msg_namelen=128, msg_iov=[{iov_base="a", iov_len=1}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 1 [pid 4846] select(6, [5], NULL, NULL, {tv_sec=2, tv_usec=0}) = 1 (in [5], left {tv_sec=1, tv_usec=999995}) [pid 4846] recvmsg(5, {msg_name={sa_family=AF_INET, sin_port=htons(4040), sin_addr=inet_addr("192.168.1.254")}, msg_namelen=128->16, msg_iov=[{iov_base="a", iov_len=64}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 1 [pid 4846] close(6) = 0 [pid 4846] close(5) = 0 [pid 4846] bpf(BPF_PROG_DETACH, {target_fd=3, attach_type=0x13 /* BPF_??? */}, 112) = 0 IPv6 test case: [pid 4846] bpf(BPF_PROG_ATTACH, {target_fd=3, attach_bpf_fd=4, attach_type=0x14 /* BPF_??? */, attach_flags=BPF_F_ALLOW_OVERRIDE}, 112) = 0 [pid 4846] socket(AF_INET6, SOCK_DGRAM, IPPROTO_IP) = 5 [pid 4846] bind(5, {sa_family=AF_INET6, sin6_port=htons(6666), inet_pton(AF_INET6, "::1", &sin6_addr), sin6_flowinfo=htonl(0), sin6_scope_id=0}, 128) = 0 [pid 4846] socket(AF_INET6, SOCK_DGRAM, IPPROTO_IP) = 6 [pid 4846] sendmsg(6, {msg_name={sa_family=AF_INET6, sin6_port=htons(6666), inet_pton(AF_INET6, "::1", &sin6_addr), sin6_flowinfo=htonl(0), sin6_scope_id=0}, msg_namelen=128, msg_iov=[{iov_base="a", iov_len=1}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 1 [pid 4846] select(6, [5], NULL, NULL, {tv_sec=2, tv_usec=0}) = 1 (in [5], left {tv_sec=1, tv_usec=999996}) [pid 4846] recvmsg(5, {msg_name={sa_family=AF_INET6, sin6_port=htons(6060), inet_pton(AF_INET6, "face:b00c:1234:5678::abcd", &sin6_addr), sin6_flowinfo=htonl(0), sin6_scope_id=0}, msg_namelen=128->28, msg_iov=[{iov_base="a", iov_len=64}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 1 [pid 4846] close(6) = 0 [pid 4846] close(5) = 0 [pid 4846] bpf(BPF_PROG_DETACH, {target_fd=3, attach_type=0x14 /* BPF_??? */}, 112) = 0 test_sock_addr run w/o strace view: # ./test_sock_addr.sh [...] Test case: recvmsg4: return code ok .. [PASS] Test case: recvmsg4: return code !ok .. [PASS] Test case: recvmsg6: return code ok .. [PASS] Test case: recvmsg6: return code !ok .. [PASS] Test case: recvmsg4: rewrite IP & port (asm) .. [PASS] Test case: recvmsg6: rewrite IP & port (asm) .. [PASS] [...] Signed-off-by: Daniel Borkmann Acked-by: Andrey Ignatov Acked-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/test_sock_addr.c | 213 +++++++++++++++++++++++++-- 1 file changed, 197 insertions(+), 16 deletions(-) diff --git a/tools/testing/selftests/bpf/test_sock_addr.c b/tools/testing/selftests/bpf/test_sock_addr.c index 3f110eaaf29c..4ecde2392327 100644 --- a/tools/testing/selftests/bpf/test_sock_addr.c +++ b/tools/testing/selftests/bpf/test_sock_addr.c @@ -76,6 +76,7 @@ struct sock_addr_test { enum { LOAD_REJECT, ATTACH_REJECT, + ATTACH_OKAY, SYSCALL_EPERM, SYSCALL_ENOTSUPP, SUCCESS, @@ -88,9 +89,13 @@ static int connect4_prog_load(const struct sock_addr_test *test); static int connect6_prog_load(const struct sock_addr_test *test); static int sendmsg_allow_prog_load(const struct sock_addr_test *test); static int sendmsg_deny_prog_load(const struct sock_addr_test *test); +static int recvmsg_allow_prog_load(const struct sock_addr_test *test); +static int recvmsg_deny_prog_load(const struct sock_addr_test *test); static int sendmsg4_rw_asm_prog_load(const struct sock_addr_test *test); +static int recvmsg4_rw_asm_prog_load(const struct sock_addr_test *test); static int sendmsg4_rw_c_prog_load(const struct sock_addr_test *test); static int sendmsg6_rw_asm_prog_load(const struct sock_addr_test *test); +static int recvmsg6_rw_asm_prog_load(const struct sock_addr_test *test); static int sendmsg6_rw_c_prog_load(const struct sock_addr_test *test); static int sendmsg6_rw_v4mapped_prog_load(const struct sock_addr_test *test); static int sendmsg6_rw_wildcard_prog_load(const struct sock_addr_test *test); @@ -507,6 +512,92 @@ static struct sock_addr_test tests[] = { SRC6_REWRITE_IP, SYSCALL_EPERM, }, + + /* recvmsg */ + { + "recvmsg4: return code ok", + recvmsg_allow_prog_load, + BPF_CGROUP_UDP4_RECVMSG, + BPF_CGROUP_UDP4_RECVMSG, + AF_INET, + SOCK_DGRAM, + NULL, + 0, + NULL, + 0, + NULL, + ATTACH_OKAY, + }, + { + "recvmsg4: return code !ok", + recvmsg_deny_prog_load, + BPF_CGROUP_UDP4_RECVMSG, + BPF_CGROUP_UDP4_RECVMSG, + AF_INET, + SOCK_DGRAM, + NULL, + 0, + NULL, + 0, + NULL, + LOAD_REJECT, + }, + { + "recvmsg6: return code ok", + recvmsg_allow_prog_load, + BPF_CGROUP_UDP6_RECVMSG, + BPF_CGROUP_UDP6_RECVMSG, + AF_INET6, + SOCK_DGRAM, + NULL, + 0, + NULL, + 0, + NULL, + ATTACH_OKAY, + }, + { + "recvmsg6: return code !ok", + recvmsg_deny_prog_load, + BPF_CGROUP_UDP6_RECVMSG, + BPF_CGROUP_UDP6_RECVMSG, + AF_INET6, + SOCK_DGRAM, + NULL, + 0, + NULL, + 0, + NULL, + LOAD_REJECT, + }, + { + "recvmsg4: rewrite IP & port (asm)", + recvmsg4_rw_asm_prog_load, + BPF_CGROUP_UDP4_RECVMSG, + BPF_CGROUP_UDP4_RECVMSG, + AF_INET, + SOCK_DGRAM, + SERV4_REWRITE_IP, + SERV4_REWRITE_PORT, + SERV4_REWRITE_IP, + SERV4_REWRITE_PORT, + SERV4_IP, + SUCCESS, + }, + { + "recvmsg6: rewrite IP & port (asm)", + recvmsg6_rw_asm_prog_load, + BPF_CGROUP_UDP6_RECVMSG, + BPF_CGROUP_UDP6_RECVMSG, + AF_INET6, + SOCK_DGRAM, + SERV6_REWRITE_IP, + SERV6_REWRITE_PORT, + SERV6_REWRITE_IP, + SERV6_REWRITE_PORT, + SERV6_IP, + SUCCESS, + }, }; static int mk_sockaddr(int domain, const char *ip, unsigned short port, @@ -765,8 +856,8 @@ static int connect6_prog_load(const struct sock_addr_test *test) return load_path(test, CONNECT6_PROG_PATH); } -static int sendmsg_ret_only_prog_load(const struct sock_addr_test *test, - int32_t rc) +static int xmsg_ret_only_prog_load(const struct sock_addr_test *test, + int32_t rc) { struct bpf_insn insns[] = { /* return rc */ @@ -778,12 +869,22 @@ static int sendmsg_ret_only_prog_load(const struct sock_addr_test *test, static int sendmsg_allow_prog_load(const struct sock_addr_test *test) { - return sendmsg_ret_only_prog_load(test, /*rc*/ 1); + return xmsg_ret_only_prog_load(test, /*rc*/ 1); } static int sendmsg_deny_prog_load(const struct sock_addr_test *test) { - return sendmsg_ret_only_prog_load(test, /*rc*/ 0); + return xmsg_ret_only_prog_load(test, /*rc*/ 0); +} + +static int recvmsg_allow_prog_load(const struct sock_addr_test *test) +{ + return xmsg_ret_only_prog_load(test, /*rc*/ 1); +} + +static int recvmsg_deny_prog_load(const struct sock_addr_test *test) +{ + return xmsg_ret_only_prog_load(test, /*rc*/ 0); } static int sendmsg4_rw_asm_prog_load(const struct sock_addr_test *test) @@ -838,6 +939,47 @@ static int sendmsg4_rw_asm_prog_load(const struct sock_addr_test *test) return load_insns(test, insns, sizeof(insns) / sizeof(struct bpf_insn)); } +static int recvmsg4_rw_asm_prog_load(const struct sock_addr_test *test) +{ + struct sockaddr_in src4_rw_addr; + + if (mk_sockaddr(AF_INET, SERV4_IP, SERV4_PORT, + (struct sockaddr *)&src4_rw_addr, + sizeof(src4_rw_addr)) == -1) + return -1; + + struct bpf_insn insns[] = { + BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), + + /* if (sk.family == AF_INET && */ + BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, + offsetof(struct bpf_sock_addr, family)), + BPF_JMP_IMM(BPF_JNE, BPF_REG_7, AF_INET, 6), + + /* sk.type == SOCK_DGRAM) { */ + BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, + offsetof(struct bpf_sock_addr, type)), + BPF_JMP_IMM(BPF_JNE, BPF_REG_7, SOCK_DGRAM, 4), + + /* user_ip4 = src4_rw_addr.sin_addr */ + BPF_MOV32_IMM(BPF_REG_7, src4_rw_addr.sin_addr.s_addr), + BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7, + offsetof(struct bpf_sock_addr, user_ip4)), + + /* user_port = src4_rw_addr.sin_port */ + BPF_MOV32_IMM(BPF_REG_7, src4_rw_addr.sin_port), + BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7, + offsetof(struct bpf_sock_addr, user_port)), + /* } */ + + /* return 1 */ + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }; + + return load_insns(test, insns, sizeof(insns) / sizeof(struct bpf_insn)); +} + static int sendmsg4_rw_c_prog_load(const struct sock_addr_test *test) { return load_path(test, SENDMSG4_PROG_PATH); @@ -901,6 +1043,39 @@ static int sendmsg6_rw_asm_prog_load(const struct sock_addr_test *test) return sendmsg6_rw_dst_asm_prog_load(test, SERV6_REWRITE_IP); } +static int recvmsg6_rw_asm_prog_load(const struct sock_addr_test *test) +{ + struct sockaddr_in6 src6_rw_addr; + + if (mk_sockaddr(AF_INET6, SERV6_IP, SERV6_PORT, + (struct sockaddr *)&src6_rw_addr, + sizeof(src6_rw_addr)) == -1) + return -1; + + struct bpf_insn insns[] = { + BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), + + /* if (sk.family == AF_INET6) { */ + BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, + offsetof(struct bpf_sock_addr, family)), + BPF_JMP_IMM(BPF_JNE, BPF_REG_7, AF_INET6, 10), + + STORE_IPV6(user_ip6, src6_rw_addr.sin6_addr.s6_addr32), + + /* user_port = dst6_rw_addr.sin6_port */ + BPF_MOV32_IMM(BPF_REG_7, src6_rw_addr.sin6_port), + BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7, + offsetof(struct bpf_sock_addr, user_port)), + /* } */ + + /* return 1 */ + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }; + + return load_insns(test, insns, sizeof(insns) / sizeof(struct bpf_insn)); +} + static int sendmsg6_rw_v4mapped_prog_load(const struct sock_addr_test *test) { return sendmsg6_rw_dst_asm_prog_load(test, SERV6_V4MAPPED_IP); @@ -1282,13 +1457,13 @@ out: return err; } -static int run_sendmsg_test_case(const struct sock_addr_test *test) +static int run_xmsg_test_case(const struct sock_addr_test *test, int max_cmsg) { socklen_t addr_len = sizeof(struct sockaddr_storage); - struct sockaddr_storage expected_src_addr; - struct sockaddr_storage requested_addr; struct sockaddr_storage expected_addr; - struct sockaddr_storage real_src_addr; + struct sockaddr_storage server_addr; + struct sockaddr_storage sendmsg_addr; + struct sockaddr_storage recvmsg_addr; int clientfd = -1; int servfd = -1; int set_cmsg; @@ -1297,20 +1472,19 @@ static int run_sendmsg_test_case(const struct sock_addr_test *test) if (test->type != SOCK_DGRAM) goto err; - if (init_addrs(test, &requested_addr, &expected_addr, - &expected_src_addr)) + if (init_addrs(test, &sendmsg_addr, &server_addr, &expected_addr)) goto err; /* Prepare server to sendmsg to */ - servfd = start_server(test->type, &expected_addr, addr_len); + servfd = start_server(test->type, &server_addr, addr_len); if (servfd == -1) goto err; - for (set_cmsg = 0; set_cmsg <= 1; ++set_cmsg) { + for (set_cmsg = 0; set_cmsg <= max_cmsg; ++set_cmsg) { if (clientfd >= 0) close(clientfd); - clientfd = sendmsg_to_server(test->type, &requested_addr, + clientfd = sendmsg_to_server(test->type, &sendmsg_addr, addr_len, set_cmsg, /*flags*/0, &err); if (err) @@ -1330,10 +1504,10 @@ static int run_sendmsg_test_case(const struct sock_addr_test *test) * specific packet may differ from the one used by default and * returned by getsockname(2). */ - if (recvmsg_from_client(servfd, &real_src_addr) == -1) + if (recvmsg_from_client(servfd, &recvmsg_addr) == -1) goto err; - if (cmp_addr(&real_src_addr, &expected_src_addr, /*cmp_port*/0)) + if (cmp_addr(&recvmsg_addr, &expected_addr, /*cmp_port*/0)) goto err; } @@ -1366,6 +1540,9 @@ static int run_test_case(int cgfd, const struct sock_addr_test *test) goto out; } else if (test->expected_result == ATTACH_REJECT || err) { goto err; + } else if (test->expected_result == ATTACH_OKAY) { + err = 0; + goto out; } switch (test->attach_type) { @@ -1379,7 +1556,11 @@ static int run_test_case(int cgfd, const struct sock_addr_test *test) break; case BPF_CGROUP_UDP4_SENDMSG: case BPF_CGROUP_UDP6_SENDMSG: - err = run_sendmsg_test_case(test); + err = run_xmsg_test_case(test, 1); + break; + case BPF_CGROUP_UDP4_RECVMSG: + case BPF_CGROUP_UDP6_RECVMSG: + err = run_xmsg_test_case(test, 0); break; default: goto err; -- cgit v1.2.3 From b714560f7b38de9f03b8670890ba130d4cc5604e Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Fri, 7 Jun 2019 01:49:02 +0200 Subject: bpf: expand section tests for test_section_names Add cgroup/recvmsg{4,6} to test_section_names as well. Test run output: # ./test_section_names libbpf: failed to guess program type based on ELF section name 'InvAliD' libbpf: supported section(type) names are: [...] libbpf: failed to guess attach type based on ELF section name 'InvAliD' libbpf: attachable section(type) names are: [...] libbpf: failed to guess program type based on ELF section name 'cgroup' libbpf: supported section(type) names are: [...] libbpf: failed to guess attach type based on ELF section name 'cgroup' libbpf: attachable section(type) names are: [...] Summary: 38 PASSED, 0 FAILED Signed-off-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/test_section_names.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/tools/testing/selftests/bpf/test_section_names.c b/tools/testing/selftests/bpf/test_section_names.c index bebd4fbca1f4..dee2f2eceb0f 100644 --- a/tools/testing/selftests/bpf/test_section_names.c +++ b/tools/testing/selftests/bpf/test_section_names.c @@ -119,6 +119,16 @@ static struct sec_name_test tests[] = { {0, BPF_PROG_TYPE_CGROUP_SOCK_ADDR, BPF_CGROUP_UDP6_SENDMSG}, {0, BPF_CGROUP_UDP6_SENDMSG}, }, + { + "cgroup/recvmsg4", + {0, BPF_PROG_TYPE_CGROUP_SOCK_ADDR, BPF_CGROUP_UDP4_RECVMSG}, + {0, BPF_CGROUP_UDP4_RECVMSG}, + }, + { + "cgroup/recvmsg6", + {0, BPF_PROG_TYPE_CGROUP_SOCK_ADDR, BPF_CGROUP_UDP6_RECVMSG}, + {0, BPF_CGROUP_UDP6_RECVMSG}, + }, { "cgroup/sysctl", {0, BPF_PROG_TYPE_CGROUP_SYSCTL, BPF_CGROUP_SYSCTL}, -- cgit v1.2.3