Re: [PATCH 1/3] [LLC]: skb allocation size for responses
From: Joonwoo Park <hidden>
Date: 2008-03-29 06:07:02
Subsystem:
llc (802.2), networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Possibly related (same subject, not in this thread)
- 2008-03-25 · Re: [PATCH 1/3] [LLC]: skb allocation size for responses · Joonwoo Park <hidden>
- 2008-03-24 · Re: [PATCH 1/3] [LLC]: skb allocation size for responses · Arnaldo Carvalho de Melo <hidden>
On Fri, Mar 28, 2008 at 10:12:02AM -0300, Arnaldo Carvalho de Melo wrote:
quoted
+static int llc_mac_header_len(unsigned short devtype) +{ + switch (devtype) { + case ARPHRD_ETHER: + case ARPHRD_LOOPBACK: + return sizeof(struct ethhdr); + } + + return __llc_tr_mac_header_len(devtype); +}Nah, just drop __llc_tr_mac_header_len altogether and have another case entry for ARPHDR_IEEE802_TR.quoted
/** * llc_alloc_frame - allocates sk_buff for frame * @dev: network device this skb will be sent over + * @type: pdu type to allocate + * @data_size: data size to allocate * * Allocates an sk_buff for frame and initializes sk_buff fields. * Returns allocated skb or %NULL when out of memory. */ -struct sk_buff *llc_alloc_frame(struct sock *sk, struct net_device *dev) +struct sk_buff *llc_alloc_frame(struct sock *sk, struct net_device *dev, + u8 type, u32 data_size) { - struct sk_buff *skb = alloc_skb(128, GFP_ATOMIC); + int hlen = type == LLC_PDU_TYPE_U ? 3 : 4; + struct sk_buff *skb; + + hlen += llc_mac_header_len(dev->type); + skb = alloc_skb(hlen + data_size, GFP_ATOMIC); if (skb) { skb_reset_mac_header(skb); - skb_reserve(skb, 50); + skb_reserve(skb, hlen);Well done, now it is better documented (LLC_PDU_TYPE_U passed) and uses less memory, no more magic numbers, good. - Arnaldo
I've respined the patch, thanks Arnaldo. --- [LLC]: skb allocation size for responses Allocate the skb for llc responses with the received packet size by using the size adjustable llc_frame_alloc. Don't allocate useless extra payload. Cleanup magic numbers. So, this fixes oops. Reported by Jim Westfall: kernel: skb_over_panic: text:c0541fc7 len:1000 put:997 head:c166ac00 data:c166ac2f tail:0xc166b017 end:0xc166ac80 dev:eth0 kernel: ------------[ cut here ]------------ kernel: kernel BUG at net/core/skbuff.c:95! Signed-off-by: Joonwoo Park <redacted> --- include/net/llc_pdu.h | 4 ++-- include/net/llc_sap.h | 7 +++++-- net/llc/llc_c_ac.c | 47 +++++++++++++++++++++++++---------------------- net/llc/llc_pdu.c | 2 +- net/llc/llc_s_ac.c | 9 +++++++-- net/llc/llc_sap.c | 27 ++++++++++++++++++++++++--- net/llc/llc_station.c | 13 ++++++++++--- 7 files changed, 74 insertions(+), 35 deletions(-)
diff --git a/include/net/llc_pdu.h b/include/net/llc_pdu.h
index 4a8f58b..75b8e29 100644
--- a/include/net/llc_pdu.h
+++ b/include/net/llc_pdu.h@@ -381,7 +381,7 @@ static inline void llc_pdu_init_as_xid_cmd(struct sk_buff *skb, xid_info->fmt_id = LLC_XID_FMT_ID; /* 0x81 */ xid_info->type = svcs_supported; xid_info->rw = rx_window << 1; /* size of receive window */ - skb_put(skb, 3); + skb_put(skb, sizeof(struct llc_xid_info)); } /**
@@ -406,7 +406,7 @@ static inline void llc_pdu_init_as_xid_rsp(struct sk_buff *skb, xid_info->fmt_id = LLC_XID_FMT_ID; xid_info->type = svcs_supported; xid_info->rw = rx_window << 1; - skb_put(skb, 3); + skb_put(skb, sizeof(struct llc_xid_info)); } /* LLC Type 2 FRMR response information field format */
diff --git a/include/net/llc_sap.h b/include/net/llc_sap.h
index 2c56dbe..ed25bec 100644
--- a/include/net/llc_sap.h
+++ b/include/net/llc_sap.h@@ -1,5 +1,8 @@ #ifndef LLC_SAP_H #define LLC_SAP_H + +#include <asm/types.h> + /* * Copyright (c) 1997 by Procom Technology,Inc. * 2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
@@ -19,8 +22,8 @@ struct sock; extern void llc_sap_rtn_pdu(struct llc_sap *sap, struct sk_buff *skb); extern void llc_save_primitive(struct sock *sk, struct sk_buff* skb, unsigned char prim); -extern struct sk_buff *llc_alloc_frame(struct sock *sk, - struct net_device *dev); +extern struct sk_buff *llc_alloc_frame(struct sock *sk, struct net_device *dev, + u8 type, u32 data_size); extern void llc_build_and_send_test_pkt(struct llc_sap *sap, struct sk_buff *skb,
diff --git a/net/llc/llc_c_ac.c b/net/llc/llc_c_ac.c
index 860140c..71a0022 100644
--- a/net/llc/llc_c_ac.c
+++ b/net/llc/llc_c_ac.c@@ -198,7 +198,7 @@ int llc_conn_ac_send_disc_cmd_p_set_x(struct sock *sk, struct sk_buff *skb) { int rc = -ENOBUFS; struct llc_sock *llc = llc_sk(sk); - struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev); + struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0); if (nskb) { struct llc_sap *sap = llc->sap;
@@ -223,7 +223,7 @@ int llc_conn_ac_send_dm_rsp_f_set_p(struct sock *sk, struct sk_buff *skb) { int rc = -ENOBUFS; struct llc_sock *llc = llc_sk(sk); - struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev); + struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0); if (nskb) { struct llc_sap *sap = llc->sap;
@@ -249,7 +249,7 @@ int llc_conn_ac_send_dm_rsp_f_set_1(struct sock *sk, struct sk_buff *skb) { int rc = -ENOBUFS; struct llc_sock *llc = llc_sk(sk); - struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev); + struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0); if (nskb) { struct llc_sap *sap = llc->sap;
@@ -282,7 +282,8 @@ int llc_conn_ac_send_frmr_rsp_f_set_x(struct sock *sk, struct sk_buff *skb) llc_pdu_decode_pf_bit(skb, &f_bit); else f_bit = 0; - nskb = llc_alloc_frame(sk, llc->dev); + nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, + sizeof(struct llc_frmr_info)); if (nskb) { struct llc_sap *sap = llc->sap;
@@ -306,7 +307,8 @@ int llc_conn_ac_resend_frmr_rsp_f_set_0(struct sock *sk, struct sk_buff *skb) { int rc = -ENOBUFS; struct llc_sock *llc = llc_sk(sk); - struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev); + struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, + sizeof(struct llc_frmr_info)); if (nskb) { struct llc_sap *sap = llc->sap;
@@ -336,7 +338,8 @@ int llc_conn_ac_resend_frmr_rsp_f_set_p(struct sock *sk, struct sk_buff *skb) struct llc_sock *llc = llc_sk(sk); llc_pdu_decode_pf_bit(skb, &f_bit); - nskb = llc_alloc_frame(sk, llc->dev); + nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, + sizeof(struct llc_frmr_info)); if (nskb) { struct llc_sap *sap = llc->sap; struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
@@ -424,7 +427,7 @@ int llc_conn_ac_resend_i_xxx_x_set_0_or_send_rr(struct sock *sk, struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb); int rc = -ENOBUFS; struct llc_sock *llc = llc_sk(sk); - struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev); + struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0); if (nskb) { struct llc_sap *sap = llc->sap;
@@ -459,7 +462,7 @@ int llc_conn_ac_send_rej_cmd_p_set_1(struct sock *sk, struct sk_buff *skb) { int rc = -ENOBUFS; struct llc_sock *llc = llc_sk(sk); - struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev); + struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0); if (nskb) { struct llc_sap *sap = llc->sap;
@@ -483,7 +486,7 @@ int llc_conn_ac_send_rej_rsp_f_set_1(struct sock *sk, struct sk_buff *skb) { int rc = -ENOBUFS; struct llc_sock *llc = llc_sk(sk); - struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev); + struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0); if (nskb) { struct llc_sap *sap = llc->sap;
@@ -507,7 +510,7 @@ int llc_conn_ac_send_rej_xxx_x_set_0(struct sock *sk, struct sk_buff *skb) { int rc = -ENOBUFS; struct llc_sock *llc = llc_sk(sk); - struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev); + struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0); if (nskb) { struct llc_sap *sap = llc->sap;
@@ -531,7 +534,7 @@ int llc_conn_ac_send_rnr_cmd_p_set_1(struct sock *sk, struct sk_buff *skb) { int rc = -ENOBUFS; struct llc_sock *llc = llc_sk(sk); - struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev); + struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0); if (nskb) { struct llc_sap *sap = llc->sap;
@@ -555,7 +558,7 @@ int llc_conn_ac_send_rnr_rsp_f_set_1(struct sock *sk, struct sk_buff *skb) { int rc = -ENOBUFS; struct llc_sock *llc = llc_sk(sk); - struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev); + struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0); if (nskb) { struct llc_sap *sap = llc->sap;
@@ -579,7 +582,7 @@ int llc_conn_ac_send_rnr_xxx_x_set_0(struct sock *sk, struct sk_buff *skb) { int rc = -ENOBUFS; struct llc_sock *llc = llc_sk(sk); - struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev); + struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0); if (nskb) { struct llc_sap *sap = llc->sap;
@@ -615,7 +618,7 @@ int llc_conn_ac_opt_send_rnr_xxx_x_set_0(struct sock *sk, struct sk_buff *skb) { int rc = -ENOBUFS; struct llc_sock *llc = llc_sk(sk); - struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev); + struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0); if (nskb) { struct llc_sap *sap = llc->sap;
@@ -639,7 +642,7 @@ int llc_conn_ac_send_rr_cmd_p_set_1(struct sock *sk, struct sk_buff *skb) { int rc = -ENOBUFS; struct llc_sock *llc = llc_sk(sk); - struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev); + struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0); if (nskb) { struct llc_sap *sap = llc->sap;
@@ -663,7 +666,7 @@ int llc_conn_ac_send_rr_rsp_f_set_1(struct sock *sk, struct sk_buff *skb) { int rc = -ENOBUFS; struct llc_sock *llc = llc_sk(sk); - struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev); + struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0); if (nskb) { struct llc_sap *sap = llc->sap;
@@ -688,7 +691,7 @@ int llc_conn_ac_send_ack_rsp_f_set_1(struct sock *sk, struct sk_buff *skb) { int rc = -ENOBUFS; struct llc_sock *llc = llc_sk(sk); - struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev); + struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0); if (nskb) { struct llc_sap *sap = llc->sap;
@@ -712,7 +715,7 @@ int llc_conn_ac_send_rr_xxx_x_set_0(struct sock *sk, struct sk_buff *skb) { int rc = -ENOBUFS; struct llc_sock *llc = llc_sk(sk); - struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev); + struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0); if (nskb) { struct llc_sap *sap = llc->sap;
@@ -736,7 +739,7 @@ int llc_conn_ac_send_ack_xxx_x_set_0(struct sock *sk, struct sk_buff *skb) { int rc = -ENOBUFS; struct llc_sock *llc = llc_sk(sk); - struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev); + struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0); if (nskb) { struct llc_sap *sap = llc->sap;
@@ -770,7 +773,7 @@ int llc_conn_ac_send_sabme_cmd_p_set_x(struct sock *sk, struct sk_buff *skb) { int rc = -ENOBUFS; struct llc_sock *llc = llc_sk(sk); - struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev); + struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0); if (nskb) { struct llc_sap *sap = llc->sap;
@@ -799,7 +802,7 @@ int llc_conn_ac_send_ua_rsp_f_set_p(struct sock *sk, struct sk_buff *skb) u8 f_bit; int rc = -ENOBUFS; struct llc_sock *llc = llc_sk(sk); - struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev); + struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0); llc_pdu_decode_pf_bit(skb, &f_bit); if (nskb) {
@@ -956,7 +959,7 @@ static int llc_conn_ac_send_rr_rsp_f_set_ackpf(struct sock *sk, { int rc = -ENOBUFS; struct llc_sock *llc = llc_sk(sk); - struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev); + struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0); if (nskb) { struct llc_sap *sap = llc->sap;
diff --git a/net/llc/llc_pdu.c b/net/llc/llc_pdu.c
index fa83243..2e6cb79 100644
--- a/net/llc/llc_pdu.c
+++ b/net/llc/llc_pdu.c@@ -241,7 +241,7 @@ void llc_pdu_init_as_frmr_rsp(struct sk_buff *skb, struct llc_pdu_sn *prev_pdu, FRMR_INFO_SET_PDU_INFO_2LONG_IND(frmr_info, vzyxw); FRMR_INFO_SET_PDU_INVALID_Nr_IND(frmr_info, vzyxw); FRMR_INFO_SET_PDU_INVALID_Ns_IND(frmr_info, vzyxw); - skb_put(skb, 5); + skb_put(skb, sizeof(struct llc_frmr_info)); } /**
diff --git a/net/llc/llc_s_ac.c b/net/llc/llc_s_ac.c
index ac3d93b..a94bd56 100644
--- a/net/llc/llc_s_ac.c
+++ b/net/llc/llc_s_ac.c@@ -103,7 +103,8 @@ int llc_sap_action_send_xid_r(struct llc_sap *sap, struct sk_buff *skb) llc_pdu_decode_sa(skb, mac_da); llc_pdu_decode_da(skb, mac_sa); llc_pdu_decode_ssap(skb, &dsap); - nskb = llc_alloc_frame(NULL, skb->dev); + nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U, + sizeof(struct llc_xid_info)); if (!nskb) goto out; llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap, dsap,
@@ -144,11 +145,15 @@ int llc_sap_action_send_test_r(struct llc_sap *sap, struct sk_buff *skb) u8 mac_da[ETH_ALEN], mac_sa[ETH_ALEN], dsap; struct sk_buff *nskb; int rc = 1; + u32 data_size; llc_pdu_decode_sa(skb, mac_da); llc_pdu_decode_da(skb, mac_sa); llc_pdu_decode_ssap(skb, &dsap); - nskb = llc_alloc_frame(NULL, skb->dev); + + /* The test request command is type U (llc_len = 3) */ + data_size = ntohs(eth_hdr(skb)->h_proto) - 3; + nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U, data_size); if (!nskb) goto out; llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap, dsap,
diff --git a/net/llc/llc_sap.c b/net/llc/llc_sap.c
index 2525165..65799b1 100644
--- a/net/llc/llc_sap.c
+++ b/net/llc/llc_sap.c@@ -24,20 +24,41 @@ #include <net/tcp_states.h> #include <linux/llc.h> +static int llc_mac_header_len(unsigned short devtype) +{ + switch (devtype) { + case ARPHRD_ETHER: + case ARPHRD_LOOPBACK: + return sizeof(struct ethhdr); +#ifdef CONFIG_TR + case ARPHDR_IEEE802_TR: + return sizeof(struct thr_hdr); +#endif + } + return 0; +} + /** * llc_alloc_frame - allocates sk_buff for frame * @dev: network device this skb will be sent over + * @type: pdu type to allocate + * @data_size: data size to allocate * * Allocates an sk_buff for frame and initializes sk_buff fields. * Returns allocated skb or %NULL when out of memory. */ -struct sk_buff *llc_alloc_frame(struct sock *sk, struct net_device *dev) +struct sk_buff *llc_alloc_frame(struct sock *sk, struct net_device *dev, + u8 type, u32 data_size) { - struct sk_buff *skb = alloc_skb(128, GFP_ATOMIC); + int hlen = type == LLC_PDU_TYPE_U ? 3 : 4; + struct sk_buff *skb; + + hlen += llc_mac_header_len(dev->type); + skb = alloc_skb(hlen + data_size, GFP_ATOMIC); if (skb) { skb_reset_mac_header(skb); - skb_reserve(skb, 50); + skb_reserve(skb, hlen); skb_reset_network_header(skb); skb_reset_transport_header(skb); skb->protocol = htons(ETH_P_802_2);
diff --git a/net/llc/llc_station.c b/net/llc/llc_station.c
index 959e7f3..83da133 100644
--- a/net/llc/llc_station.c
+++ b/net/llc/llc_station.c@@ -253,7 +253,8 @@ static int llc_station_ac_inc_xid_r_cnt_by_1(struct sk_buff *skb) static int llc_station_ac_send_null_dsap_xid_c(struct sk_buff *skb) { int rc = 1; - struct sk_buff *nskb = llc_alloc_frame(NULL, skb->dev); + struct sk_buff *nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U, + sizeof(struct llc_xid_info)); if (!nskb) goto out;
@@ -274,7 +275,8 @@ static int llc_station_ac_send_xid_r(struct sk_buff *skb) { u8 mac_da[ETH_ALEN], dsap; int rc = 1; - struct sk_buff* nskb = llc_alloc_frame(NULL, skb->dev); + struct sk_buff *nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U, + sizeof(struct llc_xid_info)); if (!nskb) goto out;
@@ -298,7 +300,12 @@ static int llc_station_ac_send_test_r(struct sk_buff *skb) { u8 mac_da[ETH_ALEN], dsap; int rc = 1; - struct sk_buff *nskb = llc_alloc_frame(NULL, skb->dev); + u32 data_size; + struct sk_buff *nskb; + + /* The test request command is type U (llc_len = 3) */ + data_size = ntohs(eth_hdr(skb)->h_proto) - 3; + nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U, data_size); if (!nskb) goto out;
--
1.5.4.3
---