| Message ID | 1471503919-30889-1-git-send-email-fgao@ikuai8.com |
|---|---|
| State | Rejected, archived |
| Delegated to: | David Miller |
| Headers | show |
On Thu, Aug 18, 2016 at 03:05:19PM +0800, fgao@ikuai8.com wrote: > From: Gao Feng <fgao@ikuai8.com> > > 1. Use PPP_ALLSTATIONS/PPP_UI instead of literal 0xff/0x03; > 2. Use one static const global fixed_ppphdr instead of two same > static variable ppph in two different functions; > 3. Use SEND_SHUTDOWN instead of literal 2; > > Signed-off-by: Gao Feng <fgao@ikuai8.com> > --- > v1: Initial patch No need to send 'v1' for the initial series. > --- a/net/l2tp/l2tp_ppp.c > +++ b/net/l2tp/l2tp_ppp.c > @@ -138,6 +138,8 @@ static const struct ppp_channel_ops pppol2tp_chan_ops = { > > static const struct proto_ops pppol2tp_ops; > > +static const unsigned char fixed_ppphdr[2] = {PPP_ALLSTATIONS, PPP_UI}; > + > /* Helpers to obtain tunnel/session contexts from sockets. > */ > static inline struct l2tp_session *pppol2tp_sock_to_session(struct sock *sk) > @@ -174,11 +176,11 @@ static int pppol2tp_recv_payload_hook(struct sk_buff *skb) > * Note that skb->data[] isn't dereferenced from a u16 ptr here since > * the field may be unaligned. > */ > - if (!pskb_may_pull(skb, 2)) > + if (!pskb_may_pull(skb, sizeof(fixed_ppphdr))) > return 1; > > - if ((skb->data[0] == 0xff) && (skb->data[1] == 0x03)) > - skb_pull(skb, 2); > + if ((PPP_ADDRESS(skb->data) == PPP_ALLSTATIONS) && (PPP_CONTROL(skb->data) == PPP_UI)) > + skb_pull(skb, sizeof(fixed_ppphdr)); > Sorry, but I find the original code clearer. It's important to be explicit about what's done with the sk_buff. Hiding skb->data[x] behind macros certainly doesn't help. Same thing for the use of sizeof(fixed_ppphdr) in pskb_may_pull(). The size of fixed_ppphdr isn't used aftewards, so it's unclear why its size was pulled. 2 was not a magic number here, it was directly related with the operations done on the skb (i.e. accessing skb->data[0] and skb->data[1]). So pskb_may_pull(skb, 2) makes perfect sense. OTOH, replacing 0xff and 0x03 with PPP_ALLSTATIONS and PPP_UI is fine. > @@ -312,7 +313,7 @@ static int pppol2tp_sendmsg(struct socket *sock, struct msghdr *m, > error = -ENOMEM; > skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) + > uhlen + session->hdr_len + > - sizeof(ppph) + total_len, > + sizeof(fixed_ppphdr) + total_len, > 0, GFP_KERNEL); > if (!skb) > goto error_put_sess_tun; > @@ -325,9 +326,9 @@ static int pppol2tp_sendmsg(struct socket *sock, struct msghdr *m, > skb_reserve(skb, uhlen); > > /* Add PPP header */ > - skb->data[0] = ppph[0]; > - skb->data[1] = ppph[1]; > - skb_put(skb, 2); > + PPP_ADDRESS(skb->data) = fixed_ppphdr[0]; > + PPP_CONTROL(skb->data) = fixed_ppphdr[1]; > + skb_put(skb, sizeof(fixed_ppphdr)); > Same here. What about + skb->data[0] = PPP_ALLSTATIONS; + skb->data[1] = PPP_UI; + skb_put(skb, 2); and removing ppph entirely? > /* Copy user data into skb */ > error = memcpy_from_msg(skb_put(skb, total_len), m, total_len); > @@ -369,7 +370,6 @@ error: > */ > static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb) > { > - static const u8 ppph[2] = { 0xff, 0x03 }; > struct sock *sk = (struct sock *) chan->private; > struct sock *sk_tun; > struct l2tp_session *session; > @@ -398,14 +398,14 @@ static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb) > sizeof(struct iphdr) + /* IP header */ > uhlen + /* UDP header (if L2TP_ENCAPTYPE_UDP) */ > session->hdr_len + /* L2TP header */ > - sizeof(ppph); /* PPP header */ > + sizeof(fixed_ppphdr); /* PPP header */ > if (skb_cow_head(skb, headroom)) > goto abort_put_sess_tun; > > /* Setup PPP header */ > - __skb_push(skb, sizeof(ppph)); > - skb->data[0] = ppph[0]; > - skb->data[1] = ppph[1]; > + __skb_push(skb, sizeof(fixed_ppphdr)); > + skb->data[0] = fixed_ppphdr[0]; > + skb->data[1] = fixed_ppphdr[1]; > Same as for pppol2tp_sendmsg(). > @@ -440,7 +440,7 @@ static void pppol2tp_session_close(struct l2tp_session *session) > BUG_ON(session->magic != L2TP_SESSION_MAGIC); > > if (sock) { > - inet_shutdown(sock, 2); > + inet_shutdown(sock, SEND_SHUTDOWN); > Ok.
On Fri, Aug 19, 2016 at 2:41 AM, Guillaume Nault <g.nault@alphalink.fr> wrote: > On Thu, Aug 18, 2016 at 03:05:19PM +0800, fgao@ikuai8.com wrote: >> From: Gao Feng <fgao@ikuai8.com> >> >> 1. Use PPP_ALLSTATIONS/PPP_UI instead of literal 0xff/0x03; >> 2. Use one static const global fixed_ppphdr instead of two same >> static variable ppph in two different functions; >> 3. Use SEND_SHUTDOWN instead of literal 2; >> >> Signed-off-by: Gao Feng <fgao@ikuai8.com> >> --- >> v1: Initial patch > No need to send 'v1' for the initial series. OK, I get it. > >> --- a/net/l2tp/l2tp_ppp.c >> +++ b/net/l2tp/l2tp_ppp.c >> @@ -138,6 +138,8 @@ static const struct ppp_channel_ops pppol2tp_chan_ops = { >> >> static const struct proto_ops pppol2tp_ops; >> >> +static const unsigned char fixed_ppphdr[2] = {PPP_ALLSTATIONS, PPP_UI}; >> + >> /* Helpers to obtain tunnel/session contexts from sockets. >> */ >> static inline struct l2tp_session *pppol2tp_sock_to_session(struct sock *sk) >> @@ -174,11 +176,11 @@ static int pppol2tp_recv_payload_hook(struct sk_buff *skb) >> * Note that skb->data[] isn't dereferenced from a u16 ptr here since >> * the field may be unaligned. >> */ >> - if (!pskb_may_pull(skb, 2)) >> + if (!pskb_may_pull(skb, sizeof(fixed_ppphdr))) >> return 1; >> >> - if ((skb->data[0] == 0xff) && (skb->data[1] == 0x03)) >> - skb_pull(skb, 2); >> + if ((PPP_ADDRESS(skb->data) == PPP_ALLSTATIONS) && (PPP_CONTROL(skb->data) == PPP_UI)) >> + skb_pull(skb, sizeof(fixed_ppphdr)); >> > Sorry, but I find the original code clearer. It's important to be > explicit about what's done with the sk_buff. Hiding skb->data[x] behind > macros certainly doesn't help. > > Same thing for the use of sizeof(fixed_ppphdr) in pskb_may_pull(). The > size of fixed_ppphdr isn't used aftewards, so it's unclear why its size > was pulled. 2 was not a magic number here, it was directly related with > the operations done on the skb (i.e. accessing skb->data[0] and > skb->data[1]). So pskb_may_pull(skb, 2) makes perfect sense. Agree now because of detail explanation. Thanks. > > OTOH, replacing 0xff and 0x03 with PPP_ALLSTATIONS and PPP_UI is fine. OK. get it. > >> @@ -312,7 +313,7 @@ static int pppol2tp_sendmsg(struct socket *sock, struct msghdr *m, >> error = -ENOMEM; >> skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) + >> uhlen + session->hdr_len + >> - sizeof(ppph) + total_len, >> + sizeof(fixed_ppphdr) + total_len, >> 0, GFP_KERNEL); >> if (!skb) >> goto error_put_sess_tun; >> @@ -325,9 +326,9 @@ static int pppol2tp_sendmsg(struct socket *sock, struct msghdr *m, >> skb_reserve(skb, uhlen); >> >> /* Add PPP header */ >> - skb->data[0] = ppph[0]; >> - skb->data[1] = ppph[1]; >> - skb_put(skb, 2); >> + PPP_ADDRESS(skb->data) = fixed_ppphdr[0]; >> + PPP_CONTROL(skb->data) = fixed_ppphdr[1]; >> + skb_put(skb, sizeof(fixed_ppphdr)); >> > Same here. What about > + skb->data[0] = PPP_ALLSTATIONS; > + skb->data[1] = PPP_UI; > + skb_put(skb, 2); > and removing ppph entirely? Agree with you. > >> /* Copy user data into skb */ >> error = memcpy_from_msg(skb_put(skb, total_len), m, total_len); >> @@ -369,7 +370,6 @@ error: >> */ >> static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb) >> { >> - static const u8 ppph[2] = { 0xff, 0x03 }; >> struct sock *sk = (struct sock *) chan->private; >> struct sock *sk_tun; >> struct l2tp_session *session; >> @@ -398,14 +398,14 @@ static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb) >> sizeof(struct iphdr) + /* IP header */ >> uhlen + /* UDP header (if L2TP_ENCAPTYPE_UDP) */ >> session->hdr_len + /* L2TP header */ >> - sizeof(ppph); /* PPP header */ >> + sizeof(fixed_ppphdr); /* PPP header */ >> if (skb_cow_head(skb, headroom)) >> goto abort_put_sess_tun; >> >> /* Setup PPP header */ >> - __skb_push(skb, sizeof(ppph)); >> - skb->data[0] = ppph[0]; >> - skb->data[1] = ppph[1]; >> + __skb_push(skb, sizeof(fixed_ppphdr)); >> + skb->data[0] = fixed_ppphdr[0]; >> + skb->data[1] = fixed_ppphdr[1]; >> > Same as for pppol2tp_sendmsg(). > >> @@ -440,7 +440,7 @@ static void pppol2tp_session_close(struct l2tp_session *session) >> BUG_ON(session->magic != L2TP_SESSION_MAGIC); >> >> if (sock) { >> - inet_shutdown(sock, 2); >> + inet_shutdown(sock, SEND_SHUTDOWN); >> > Ok. Regards Feng
From: fgao@ikuai8.com Date: Thu, 18 Aug 2016 15:05:19 +0800 > @@ -138,6 +138,8 @@ static const struct ppp_channel_ops pppol2tp_chan_ops = { > > static const struct proto_ops pppol2tp_ops; > > +static const unsigned char fixed_ppphdr[2] = {PPP_ALLSTATIONS, PPP_UI}; > + > /* Helpers to obtain tunnel/session contexts from sockets. > */ > static inline struct l2tp_session *pppol2tp_sock_to_session(struct sock *sk) Same problem as the pptp patch, I'm not applying this.
diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c index d9560aa..0e69eb4 100644 --- a/net/l2tp/l2tp_ppp.c +++ b/net/l2tp/l2tp_ppp.c @@ -138,6 +138,8 @@ static const struct ppp_channel_ops pppol2tp_chan_ops = { static const struct proto_ops pppol2tp_ops; +static const unsigned char fixed_ppphdr[2] = {PPP_ALLSTATIONS, PPP_UI}; + /* Helpers to obtain tunnel/session contexts from sockets. */ static inline struct l2tp_session *pppol2tp_sock_to_session(struct sock *sk) @@ -174,11 +176,11 @@ static int pppol2tp_recv_payload_hook(struct sk_buff *skb) * Note that skb->data[] isn't dereferenced from a u16 ptr here since * the field may be unaligned. */ - if (!pskb_may_pull(skb, 2)) + if (!pskb_may_pull(skb, sizeof(fixed_ppphdr))) return 1; - if ((skb->data[0] == 0xff) && (skb->data[1] == 0x03)) - skb_pull(skb, 2); + if ((PPP_ADDRESS(skb->data) == PPP_ALLSTATIONS) && (PPP_CONTROL(skb->data) == PPP_UI)) + skb_pull(skb, sizeof(fixed_ppphdr)); return 0; } @@ -282,7 +284,6 @@ static void pppol2tp_session_sock_put(struct l2tp_session *session) static int pppol2tp_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len) { - static const unsigned char ppph[2] = { 0xff, 0x03 }; struct sock *sk = sock->sk; struct sk_buff *skb; int error; @@ -312,7 +313,7 @@ static int pppol2tp_sendmsg(struct socket *sock, struct msghdr *m, error = -ENOMEM; skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) + uhlen + session->hdr_len + - sizeof(ppph) + total_len, + sizeof(fixed_ppphdr) + total_len, 0, GFP_KERNEL); if (!skb) goto error_put_sess_tun; @@ -325,9 +326,9 @@ static int pppol2tp_sendmsg(struct socket *sock, struct msghdr *m, skb_reserve(skb, uhlen); /* Add PPP header */ - skb->data[0] = ppph[0]; - skb->data[1] = ppph[1]; - skb_put(skb, 2); + PPP_ADDRESS(skb->data) = fixed_ppphdr[0]; + PPP_CONTROL(skb->data) = fixed_ppphdr[1]; + skb_put(skb, sizeof(fixed_ppphdr)); /* Copy user data into skb */ error = memcpy_from_msg(skb_put(skb, total_len), m, total_len); @@ -369,7 +370,6 @@ error: */ static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb) { - static const u8 ppph[2] = { 0xff, 0x03 }; struct sock *sk = (struct sock *) chan->private; struct sock *sk_tun; struct l2tp_session *session; @@ -398,14 +398,14 @@ static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb) sizeof(struct iphdr) + /* IP header */ uhlen + /* UDP header (if L2TP_ENCAPTYPE_UDP) */ session->hdr_len + /* L2TP header */ - sizeof(ppph); /* PPP header */ + sizeof(fixed_ppphdr); /* PPP header */ if (skb_cow_head(skb, headroom)) goto abort_put_sess_tun; /* Setup PPP header */ - __skb_push(skb, sizeof(ppph)); - skb->data[0] = ppph[0]; - skb->data[1] = ppph[1]; + __skb_push(skb, sizeof(fixed_ppphdr)); + skb->data[0] = fixed_ppphdr[0]; + skb->data[1] = fixed_ppphdr[1]; local_bh_disable(); l2tp_xmit_skb(session, skb, session->hdr_len); @@ -440,7 +440,7 @@ static void pppol2tp_session_close(struct l2tp_session *session) BUG_ON(session->magic != L2TP_SESSION_MAGIC); if (sock) { - inet_shutdown(sock, 2); + inet_shutdown(sock, SEND_SHUTDOWN); /* Don't let the session go away before our socket does */ l2tp_session_inc_refcount(session); }