net/tcp-ao: Return void from functions that can no longer fail

Since tcp-ao now uses the crypto library API instead of crypto_ahash,
and MACs and keys now have a statically-known maximum size, many tcp-ao
functions can no longer fail.  Propagate this change up into the return
types of various functions.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Link: https://patch.msgid.link/20260427172727.9310-5-ebiggers@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/include/net/tcp.h b/include/net/tcp.h
index fb2bc9edc7de01bfc494afa828428723a352c02b..35fc6b35b21629bee849abdaecdbff94a9f5bf5a 100644 (file)
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -2520,9 +2520,9 @@ struct tcp_sock_af_ops {
        struct tcp_ao_key *(*ao_lookup)(const struct sock *sk,
                                        struct sock *addr_sk,
                                        int sndid, int rcvid);
-       int (*ao_calc_key_sk)(struct tcp_ao_key *mkt, u8 *key,
-                             const struct sock *sk,
-                             __be32 sisn, __be32 disn, bool send);
+       void (*ao_calc_key_sk)(struct tcp_ao_key *mkt, u8 *key,
+                              const struct sock *sk,
+                              __be32 sisn, __be32 disn, bool send);
        int (*calc_ao_hash)(char *location, struct tcp_ao_key *ao,
                            const struct sock *sk, const struct sk_buff *skb,
                            const u8 *tkey, int hash_offset, u32 sne);
@@ -2543,7 +2543,7 @@ struct tcp_request_sock_ops {
        struct tcp_ao_key *(*ao_lookup)(const struct sock *sk,
                                        struct request_sock *req,
                                        int sndid, int rcvid);
-       int (*ao_calc_key)(struct tcp_ao_key *mkt, u8 *key, struct request_sock *sk);
+       void (*ao_calc_key)(struct tcp_ao_key *mkt, u8 *key, struct request_sock *sk);
        int (*ao_synack_hash)(char *ao_hash, struct tcp_ao_key *mkt,
                              struct request_sock *req, const struct sk_buff *skb,
                              int hash_offset, u32 sne);

diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h
index 20997aef3b0d81e96d3a1c3f864db21aa06891e8..29fd7b735afaf3b324ba19eb05f84dd2d21f9266 100644 (file)
--- a/include/net/tcp_ao.h
+++ b/include/net/tcp_ao.h
@@ -187,9 +187,9 @@ struct tcp6_ao_context {
 #define TCP_AO_ESTABLISHED (TCPF_ESTABLISHED | TCPF_FIN_WAIT1 | TCPF_FIN_WAIT2 | \
                            TCPF_CLOSE_WAIT | TCPF_LAST_ACK | TCPF_CLOSING)
 
-int tcp_ao_transmit_skb(struct sock *sk, struct sk_buff *skb,
-                       struct tcp_ao_key *key, struct tcphdr *th,
-                       __u8 *hash_location);
+void tcp_ao_transmit_skb(struct sock *sk, struct sk_buff *skb,
+                        struct tcp_ao_key *key, struct tcphdr *th,
+                        __u8 *hash_location);
 void tcp_ao_mac_update(struct tcp_ao_mac_ctx *mac_ctx, const void *data,
                       size_t data_len);
 int tcp_ao_hash_skb(unsigned short int family,
@@ -238,11 +238,11 @@ struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk,
 int tcp_v4_ao_synack_hash(char *ao_hash, struct tcp_ao_key *mkt,
                          struct request_sock *req, const struct sk_buff *skb,
                          int hash_offset, u32 sne);
-int tcp_v4_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
-                         const struct sock *sk,
-                         __be32 sisn, __be32 disn, bool send);
-int tcp_v4_ao_calc_key_rsk(struct tcp_ao_key *mkt, u8 *key,
-                          struct request_sock *req);
+void tcp_v4_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
+                          const struct sock *sk,
+                          __be32 sisn, __be32 disn, bool send);
+void tcp_v4_ao_calc_key_rsk(struct tcp_ao_key *mkt, u8 *key,
+                           struct request_sock *req);
 struct tcp_ao_key *tcp_v4_ao_lookup_rsk(const struct sock *sk,
                                        struct request_sock *req,
                                        int sndid, int rcvid);
@@ -250,16 +250,17 @@ int tcp_v4_ao_hash_skb(char *ao_hash, struct tcp_ao_key *key,
                       const struct sock *sk, const struct sk_buff *skb,
                       const u8 *tkey, int hash_offset, u32 sne);
 /* ipv6 specific functions */
-int tcp_v6_ao_hash_pseudoheader(struct tcp_ao_mac_ctx *mac_ctx,
-                               const struct in6_addr *daddr,
-                               const struct in6_addr *saddr, int nbytes);
-int tcp_v6_ao_calc_key_skb(struct tcp_ao_key *mkt, u8 *key,
-                          const struct sk_buff *skb, __be32 sisn, __be32 disn);
-int tcp_v6_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
-                         const struct sock *sk, __be32 sisn,
-                         __be32 disn, bool send);
-int tcp_v6_ao_calc_key_rsk(struct tcp_ao_key *mkt, u8 *key,
-                          struct request_sock *req);
+void tcp_v6_ao_hash_pseudoheader(struct tcp_ao_mac_ctx *mac_ctx,
+                                const struct in6_addr *daddr,
+                                const struct in6_addr *saddr, int nbytes);
+void tcp_v6_ao_calc_key_skb(struct tcp_ao_key *mkt, u8 *key,
+                           const struct sk_buff *skb, __be32 sisn,
+                           __be32 disn);
+void tcp_v6_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
+                          const struct sock *sk, __be32 sisn,
+                          __be32 disn, bool send);
+void tcp_v6_ao_calc_key_rsk(struct tcp_ao_key *mkt, u8 *key,
+                           struct request_sock *req);
 struct tcp_ao_key *tcp_v6_ao_lookup(const struct sock *sk,
                                    struct sock *addr_sk, int sndid, int rcvid);
 struct tcp_ao_key *tcp_v6_ao_lookup_rsk(const struct sock *sk,
@@ -279,11 +280,10 @@ void tcp_ao_syncookie(struct sock *sk, const struct sk_buff *skb,
                      struct request_sock *req, unsigned short int family);
 #else /* CONFIG_TCP_AO */
 
-static inline int tcp_ao_transmit_skb(struct sock *sk, struct sk_buff *skb,
-                                     struct tcp_ao_key *key, struct tcphdr *th,
-                                     __u8 *hash_location)
+static inline void tcp_ao_transmit_skb(struct sock *sk, struct sk_buff *skb,
+                                      struct tcp_ao_key *key,
+                                      struct tcphdr *th, __u8 *hash_location)
 {
-       return 0;
 }
 
 static inline void tcp_ao_syncookie(struct sock *sk, const struct sk_buff *skb,

diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
index 69f1d6d26562e033af0b083e7ac5bef4bfeb8f52..36a64c1cd8c994a76ad8da2adc545cc376382a58 100644 (file)
--- a/net/ipv4/tcp_ao.c
+++ b/net/ipv4/tcp_ao.c
@@ -435,10 +435,10 @@ void tcp_ao_time_wait(struct tcp_timewait_sock *tcptw, struct tcp_sock *tp)
 }
 
 /* 4 tuple and ISNs are expected in NBO */
-static int tcp_v4_ao_calc_key(struct tcp_ao_key *mkt, u8 *key,
-                             __be32 saddr, __be32 daddr,
-                             __be16 sport, __be16 dport,
-                             __be32 sisn,  __be32 disn)
+static void tcp_v4_ao_calc_key(struct tcp_ao_key *mkt, u8 *key,
+                              __be32 saddr, __be32 daddr,
+                              __be16 sport, __be16 dport,
+                              __be32 sisn, __be32 disn)
 {
        /* See RFC5926 3.1.1 */
        struct kdf_input_block {
@@ -461,76 +461,78 @@ static int tcp_v4_ao_calc_key(struct tcp_ao_key *mkt, u8 *key,
        };
 
        tcp_ao_calc_traffic_key(mkt, key, &input, sizeof(input));
-       return 0;
 }
 
-int tcp_v4_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
-                         const struct sock *sk,
-                         __be32 sisn, __be32 disn, bool send)
+void tcp_v4_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
+                          const struct sock *sk,
+                          __be32 sisn, __be32 disn, bool send)
 {
        if (send)
-               return tcp_v4_ao_calc_key(mkt, key, sk->sk_rcv_saddr,
-                                         sk->sk_daddr, htons(sk->sk_num),
-                                         sk->sk_dport, sisn, disn);
+               tcp_v4_ao_calc_key(mkt, key, sk->sk_rcv_saddr, sk->sk_daddr,
+                                  htons(sk->sk_num), sk->sk_dport, sisn, disn);
        else
-               return tcp_v4_ao_calc_key(mkt, key, sk->sk_daddr,
-                                         sk->sk_rcv_saddr, sk->sk_dport,
-                                         htons(sk->sk_num), disn, sisn);
+               tcp_v4_ao_calc_key(mkt, key, sk->sk_daddr, sk->sk_rcv_saddr,
+                                  sk->sk_dport, htons(sk->sk_num), disn, sisn);
 }
 
 static int tcp_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
                              const struct sock *sk,
                              __be32 sisn, __be32 disn, bool send)
 {
-       if (mkt->family == AF_INET)
-               return tcp_v4_ao_calc_key_sk(mkt, key, sk, sisn, disn, send);
+       if (mkt->family == AF_INET) {
+               tcp_v4_ao_calc_key_sk(mkt, key, sk, sisn, disn, send);
+               return 0;
+       }
 #if IS_ENABLED(CONFIG_IPV6)
-       else if (mkt->family == AF_INET6)
-               return tcp_v6_ao_calc_key_sk(mkt, key, sk, sisn, disn, send);
+       if (mkt->family == AF_INET6) {
+               tcp_v6_ao_calc_key_sk(mkt, key, sk, sisn, disn, send);
+               return 0;
+       }
 #endif
-       else
-               return -EOPNOTSUPP;
+       return -EOPNOTSUPP;
 }
 
-int tcp_v4_ao_calc_key_rsk(struct tcp_ao_key *mkt, u8 *key,
-                          struct request_sock *req)
+void tcp_v4_ao_calc_key_rsk(struct tcp_ao_key *mkt, u8 *key,
+                           struct request_sock *req)
 {
        struct inet_request_sock *ireq = inet_rsk(req);
 
-       return tcp_v4_ao_calc_key(mkt, key,
-                                 ireq->ir_loc_addr, ireq->ir_rmt_addr,
-                                 htons(ireq->ir_num), ireq->ir_rmt_port,
-                                 htonl(tcp_rsk(req)->snt_isn),
-                                 htonl(tcp_rsk(req)->rcv_isn));
+       tcp_v4_ao_calc_key(mkt, key, ireq->ir_loc_addr, ireq->ir_rmt_addr,
+                          htons(ireq->ir_num), ireq->ir_rmt_port,
+                          htonl(tcp_rsk(req)->snt_isn),
+                          htonl(tcp_rsk(req)->rcv_isn));
 }
 
-static int tcp_v4_ao_calc_key_skb(struct tcp_ao_key *mkt, u8 *key,
-                                 const struct sk_buff *skb,
-                                 __be32 sisn, __be32 disn)
+static void tcp_v4_ao_calc_key_skb(struct tcp_ao_key *mkt, u8 *key,
+                                  const struct sk_buff *skb,
+                                  __be32 sisn, __be32 disn)
 {
        const struct iphdr *iph = ip_hdr(skb);
        const struct tcphdr *th = tcp_hdr(skb);
 
-       return tcp_v4_ao_calc_key(mkt, key, iph->saddr, iph->daddr,
-                                 th->source, th->dest, sisn, disn);
+       tcp_v4_ao_calc_key(mkt, key, iph->saddr, iph->daddr, th->source,
+                          th->dest, sisn, disn);
 }
 
 static int tcp_ao_calc_key_skb(struct tcp_ao_key *mkt, u8 *key,
                               const struct sk_buff *skb,
                               __be32 sisn, __be32 disn, int family)
 {
-       if (family == AF_INET)
-               return tcp_v4_ao_calc_key_skb(mkt, key, skb, sisn, disn);
+       if (family == AF_INET) {
+               tcp_v4_ao_calc_key_skb(mkt, key, skb, sisn, disn);
+               return 0;
+       }
 #if IS_ENABLED(CONFIG_IPV6)
-       else if (family == AF_INET6)
-               return tcp_v6_ao_calc_key_skb(mkt, key, skb, sisn, disn);
+       if (family == AF_INET6) {
+               tcp_v6_ao_calc_key_skb(mkt, key, skb, sisn, disn);
+               return 0;
+       }
 #endif
        return -EAFNOSUPPORT;
 }
 
-static int tcp_v4_ao_hash_pseudoheader(struct tcp_ao_mac_ctx *mac_ctx,
-                                      __be32 daddr, __be32 saddr,
-                                      int nbytes)
+static void tcp_v4_ao_hash_pseudoheader(struct tcp_ao_mac_ctx *mac_ctx,
+                                       __be32 daddr, __be32 saddr, int nbytes)
 {
        struct tcp4_pseudohdr phdr = {
                .saddr = saddr,
@@ -541,7 +543,6 @@ static int tcp_v4_ao_hash_pseudoheader(struct tcp_ao_mac_ctx *mac_ctx,
        };
 
        tcp_ao_mac_update(mac_ctx, &phdr, sizeof(phdr));
-       return 0;
 }
 
 static int tcp_ao_hash_pseudoheader(unsigned short int family,
@@ -553,31 +554,38 @@ static int tcp_ao_hash_pseudoheader(unsigned short int family,
 
        /* TODO: Can we rely on checksum being zero to mean outbound pkt? */
        if (!th->check) {
-               if (family == AF_INET)
-                       return tcp_v4_ao_hash_pseudoheader(mac_ctx, sk->sk_daddr,
-                                       sk->sk_rcv_saddr, skb->len);
+               if (family == AF_INET) {
+                       tcp_v4_ao_hash_pseudoheader(mac_ctx, sk->sk_daddr,
+                                                   sk->sk_rcv_saddr, skb->len);
+                       return 0;
+               }
 #if IS_ENABLED(CONFIG_IPV6)
-               else if (family == AF_INET6)
-                       return tcp_v6_ao_hash_pseudoheader(mac_ctx, &sk->sk_v6_daddr,
-                                       &sk->sk_v6_rcv_saddr, skb->len);
+               if (family == AF_INET6) {
+                       tcp_v6_ao_hash_pseudoheader(mac_ctx, &sk->sk_v6_daddr,
+                                                   &sk->sk_v6_rcv_saddr,
+                                                   skb->len);
+                       return 0;
+               }
 #endif
-               else
-                       return -EAFNOSUPPORT;
+               return -EAFNOSUPPORT;
        }
 
        if (family == AF_INET) {
                const struct iphdr *iph = ip_hdr(skb);
 
-               return tcp_v4_ao_hash_pseudoheader(mac_ctx, iph->daddr,
-                               iph->saddr, skb->len);
+               tcp_v4_ao_hash_pseudoheader(mac_ctx, iph->daddr, iph->saddr,
+                                           skb->len);
+               return 0;
+       }
 #if IS_ENABLED(CONFIG_IPV6)
-       } else if (family == AF_INET6) {
+       if (family == AF_INET6) {
                const struct ipv6hdr *iph = ipv6_hdr(skb);
 
-               return tcp_v6_ao_hash_pseudoheader(mac_ctx, &iph->daddr,
-                               &iph->saddr, skb->len);
-#endif
+               tcp_v6_ao_hash_pseudoheader(mac_ctx, &iph->daddr, &iph->saddr,
+                                           skb->len);
+               return 0;
        }
+#endif
        return -EAFNOSUPPORT;
 }
 
@@ -740,11 +748,8 @@ int tcp_v4_ao_synack_hash(char *ao_hash, struct tcp_ao_key *ao_key,
                          int hash_offset, u32 sne)
 {
        u8 tkey_buf[TCP_AO_MAX_TRAFFIC_KEY_LEN];
-       int err;
 
-       err = tcp_v4_ao_calc_key_rsk(ao_key, tkey_buf, req);
-       if (err)
-               return err;
+       tcp_v4_ao_calc_key_rsk(ao_key, tkey_buf, req);
 
        return tcp_ao_hash_skb(AF_INET, ao_hash, ao_key, req_to_sk(req), skb,
                               tkey_buf, hash_offset, sne);
@@ -857,9 +862,9 @@ int tcp_ao_prepare_reset(const struct sock *sk, struct sk_buff *skb,
        return 0;
 }
 
-int tcp_ao_transmit_skb(struct sock *sk, struct sk_buff *skb,
-                       struct tcp_ao_key *key, struct tcphdr *th,
-                       __u8 *hash_location)
+void tcp_ao_transmit_skb(struct sock *sk, struct sk_buff *skb,
+                        struct tcp_ao_key *key, struct tcphdr *th,
+                        __u8 *hash_location)
 {
        struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
        u8 tkey_buf[TCP_AO_MAX_TRAFFIC_KEY_LEN];
@@ -887,7 +892,6 @@ int tcp_ao_transmit_skb(struct sock *sk, struct sk_buff *skb,
                                 ntohl(th->seq));
        tp->af_specific->calc_ao_hash(hash_location, key, sk, skb, traffic_key,
                                      hash_location - (u8 *)th, sne);
-       return 0;
 }
 
 static struct tcp_ao_key *tcp_ao_inbound_lookup(unsigned short int family,

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index c8d7b5d20d1874bb7840e1c480195076830f1058..75eb18a2ad4e7ee126806e7a7cbf3d27a452cba5 100644 (file)
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1657,14 +1657,8 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
                                               key.md5_key, sk, skb);
 #endif
        } else if (tcp_key_is_ao(&key)) {
-               int err;
-
-               err = tcp_ao_transmit_skb(sk, skb, key.ao_key, th,
-                                         opts.hash_location);
-               if (err) {
-                       sk_skb_reason_drop(sk, skb, SKB_DROP_REASON_NOT_SPECIFIED);
-                       return -ENOMEM;
-               }
+               tcp_ao_transmit_skb(sk, skb, key.ao_key, th,
+                                   opts.hash_location);
        }
 
        /* BPF prog is the last one writing header option */

diff --git a/net/ipv6/tcp_ao.c b/net/ipv6/tcp_ao.c
index bf30b970181d76f8afec444465f4eab1e33a125d..01a8472805d1dfc15663bdcd1e5d5d082b9cc4b2 100644 (file)
--- a/net/ipv6/tcp_ao.c
+++ b/net/ipv6/tcp_ao.c
@@ -12,11 +12,11 @@
 #include <net/tcp.h>
 #include <net/ipv6.h>
 
-static int tcp_v6_ao_calc_key(struct tcp_ao_key *mkt, u8 *key,
-                             const struct in6_addr *saddr,
-                             const struct in6_addr *daddr,
-                             __be16 sport, __be16 dport,
-                             __be32 sisn, __be32 disn)
+static void tcp_v6_ao_calc_key(struct tcp_ao_key *mkt, u8 *key,
+                              const struct in6_addr *saddr,
+                              const struct in6_addr *daddr,
+                              __be16 sport, __be16 dport,
+                              __be32 sisn, __be32 disn)
 {
        struct kdf_input_block {
                u8                      counter;
@@ -38,45 +38,42 @@ static int tcp_v6_ao_calc_key(struct tcp_ao_key *mkt, u8 *key,
        };
 
        tcp_ao_calc_traffic_key(mkt, key, &input, sizeof(input));
-       return 0;
 }
 
-int tcp_v6_ao_calc_key_skb(struct tcp_ao_key *mkt, u8 *key,
-                          const struct sk_buff *skb,
-                          __be32 sisn, __be32 disn)
+void tcp_v6_ao_calc_key_skb(struct tcp_ao_key *mkt, u8 *key,
+                           const struct sk_buff *skb, __be32 sisn, __be32 disn)
 {
        const struct ipv6hdr *iph = ipv6_hdr(skb);
        const struct tcphdr *th = tcp_hdr(skb);
 
-       return tcp_v6_ao_calc_key(mkt, key, &iph->saddr,
-                                 &iph->daddr, th->source,
-                                 th->dest, sisn, disn);
+       tcp_v6_ao_calc_key(mkt, key, &iph->saddr, &iph->daddr, th->source,
+                          th->dest, sisn, disn);
 }
 
-int tcp_v6_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
-                         const struct sock *sk, __be32 sisn,
-                         __be32 disn, bool send)
+void tcp_v6_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
+                          const struct sock *sk, __be32 sisn,
+                          __be32 disn, bool send)
 {
        if (send)
-               return tcp_v6_ao_calc_key(mkt, key, &sk->sk_v6_rcv_saddr,
-                                         &sk->sk_v6_daddr, htons(sk->sk_num),
-                                         sk->sk_dport, sisn, disn);
+               tcp_v6_ao_calc_key(mkt, key, &sk->sk_v6_rcv_saddr,
+                                  &sk->sk_v6_daddr, htons(sk->sk_num),
+                                  sk->sk_dport, sisn, disn);
        else
-               return tcp_v6_ao_calc_key(mkt, key, &sk->sk_v6_daddr,
-                                         &sk->sk_v6_rcv_saddr, sk->sk_dport,
-                                         htons(sk->sk_num), disn, sisn);
+               tcp_v6_ao_calc_key(mkt, key, &sk->sk_v6_daddr,
+                                  &sk->sk_v6_rcv_saddr, sk->sk_dport,
+                                  htons(sk->sk_num), disn, sisn);
 }
 
-int tcp_v6_ao_calc_key_rsk(struct tcp_ao_key *mkt, u8 *key,
-                          struct request_sock *req)
+void tcp_v6_ao_calc_key_rsk(struct tcp_ao_key *mkt, u8 *key,
+                           struct request_sock *req)
 {
        struct inet_request_sock *ireq = inet_rsk(req);
 
-       return tcp_v6_ao_calc_key(mkt, key,
-                       &ireq->ir_v6_loc_addr, &ireq->ir_v6_rmt_addr,
-                       htons(ireq->ir_num), ireq->ir_rmt_port,
-                       htonl(tcp_rsk(req)->snt_isn),
-                       htonl(tcp_rsk(req)->rcv_isn));
+       tcp_v6_ao_calc_key(mkt, key,
+                          &ireq->ir_v6_loc_addr, &ireq->ir_v6_rmt_addr,
+                          htons(ireq->ir_num), ireq->ir_rmt_port,
+                          htonl(tcp_rsk(req)->snt_isn),
+                          htonl(tcp_rsk(req)->rcv_isn));
 }
 
 struct tcp_ao_key *tcp_v6_ao_lookup(const struct sock *sk,
@@ -104,9 +101,9 @@ struct tcp_ao_key *tcp_v6_ao_lookup_rsk(const struct sock *sk,
                                AF_INET6, sndid, rcvid);
 }
 
-int tcp_v6_ao_hash_pseudoheader(struct tcp_ao_mac_ctx *mac_ctx,
-                               const struct in6_addr *daddr,
-                               const struct in6_addr *saddr, int nbytes)
+void tcp_v6_ao_hash_pseudoheader(struct tcp_ao_mac_ctx *mac_ctx,
+                                const struct in6_addr *daddr,
+                                const struct in6_addr *saddr, int nbytes)
 {
        /* 1. TCP pseudo-header (RFC2460) */
        struct tcp6_pseudohdr phdr = {
@@ -117,7 +114,6 @@ int tcp_v6_ao_hash_pseudoheader(struct tcp_ao_mac_ctx *mac_ctx,
        };
 
        tcp_ao_mac_update(mac_ctx, &phdr, sizeof(phdr));
-       return 0;
 }
 
 int tcp_v6_ao_hash_skb(char *ao_hash, struct tcp_ao_key *key,
@@ -139,11 +135,8 @@ int tcp_v6_ao_synack_hash(char *ao_hash, struct tcp_ao_key *ao_key,
                          int hash_offset, u32 sne)
 {
        u8 tkey_buf[TCP_AO_MAX_TRAFFIC_KEY_LEN];
-       int err;
 
-       err = tcp_v6_ao_calc_key_rsk(ao_key, tkey_buf, req);
-       if (err)
-               return err;
+       tcp_v6_ao_calc_key_rsk(ao_key, tkey_buf, req);
 
        return tcp_ao_hash_skb(AF_INET6, ao_hash, ao_key, req_to_sk(req), skb,
                               tkey_buf, hash_offset, sne);