/* * X.25 Packet Layer release 002 * * This is ALPHA test software. This code may break your machine, randomly fail to work with new * releases, misbehave and/or generally screw up. It might even work. * * This code REQUIRES 2.1.15 or higher * * This module: * This module is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * * History * X.25 001 Jonathan Naylor Started coding. * 2000-09-04 Henner Eisen Prevent freeing a dangling skb. */ #define pr_fmt(fmt) "X25: " fmt #include #include #include #include #include #include #include #include static int x25_receive_data(struct sk_buff *skb, struct x25_neigh *nb) { struct sock *sk; unsigned short frametype; unsigned int lci; if (!pskb_may_pull(skb, X25_STD_MIN_LEN)) return 0; frametype = skb->data[2]; lci = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF); /* * LCI of zero is always for us, and its always a link control * frame. */ if (lci == 0) { x25_link_control(skb, nb, frametype); return 0; } /* * Find an existing socket. */ if ((sk = x25_find_socket(lci, nb)) != NULL) { int queued = 1; skb_reset_transport_header(skb); bh_lock_sock(sk); if (!sock_owned_by_user(sk)) { queued = x25_process_rx_frame(sk, skb); } else { queued = !sk_add_backlog(sk, skb, sk->sk_rcvbuf); } bh_unlock_sock(sk); sock_put(sk); return queued; } /* * Is is a Call Request ? if so process it. */ if (frametype == X25_CALL_REQUEST) return x25_rx_call_request(skb, nb, lci); /* * Its not a Call Request, nor is it a control frame. * Can we forward it? */ if (x25_forward_data(lci, nb, skb)) { if (frametype == X25_CLEAR_CONFIRMATION) { x25_clear_forward_by_lci(lci); } kfree_skb(skb); return 1; } /* x25_transmit_clear_request(nb, lci, 0x0D); */ if (frametype != X25_CLEAR_CONFIRMATION) pr_debug("x25_receive_data(): unknown frame type %2x\n",frametype); return 0; } int x25_lapb_receive_frame(struct sk_buff *skb, struct net_device *dev, struct packet_type *ptype, struct net_device *orig_dev) { struct sk_buff *nskb; struct x25_neigh *nb; if (!net_eq(dev_net(dev), &init_net)) goto drop; nskb = skb_copy(skb, GFP_ATOMIC); if (!nskb) goto drop; kfree_skb(skb); skb = nskb; /* * Packet received from unrecognised device, throw it away. */ nb = x25_get_neigh(dev); if (!nb) { pr_debug("unknown neighbour - %s\n", dev->name); goto drop; } if (!pskb_may_pull(skb, 1)) return 0; switch (skb->data[0]) { case X25_IFACE_DATA: skb_pull(skb, 1); if (x25_receive_data(skb, nb)) { x25_neigh_put(nb); goto out; } break; case X25_IFACE_CONNECT: x25_link_established(nb); break; case X25_IFACE_DISCONNECT: x25_link_terminated(nb); break; } x25_neigh_put(nb); drop: kfree_skb(skb); out: return 0; } void x25_establish_link(struct x25_neigh *nb) { struct sk_buff *skb; unsigned char *ptr; switch (nb->dev->type) { case ARPHRD_X25: if ((skb = alloc_skb(1, GFP_ATOMIC)) == NULL) { pr_err("x25_dev: out of memory\n"); return; } ptr = skb_put(skb, 1); *ptr = X25_IFACE_CONNECT; break; #if IS_ENABLED(CONFIG_LLC) case ARPHRD_ETHER: return; #endif default: return; } skb->protocol = htons(ETH_P_X25); skb->dev = nb->dev; dev_queue_xmit(skb); } void x25_terminate_link(struct x25_neigh *nb) { struct sk_buff *skb; unsigned char *ptr; #if IS_ENABLED(CONFIG_LLC) if (nb->dev->type == ARPHRD_ETHER) return; #endif if (nb->dev->type != ARPHRD_X25) return; skb = alloc_skb(1, GFP_ATOMIC); if (!skb) { pr_err("x25_dev: out of memory\n"); return; } ptr = skb_put(skb, 1); *ptr = X25_IFACE_DISCONNECT; skb->protocol = htons(ETH_P_X25); skb->dev = nb->dev; dev_queue_xmit(skb); } void x25_send_frame(struct sk_buff *skb, struct x25_neigh *nb) { unsigned char *dptr; skb_reset_network_header(skb); switch (nb->dev->type) { case ARPHRD_X25: dptr = skb_push(skb, 1); *dptr = X25_IFACE_DATA; break; #if IS_ENABLED(CONFIG_LLC) case ARPHRD_ETHER: kfree_skb(skb); return; #endif default: kfree_skb(skb); return; } skb->protocol = htons(ETH_P_X25); skb->dev = nb->dev; dev_queue_xmit(skb); } name='dt' onchange='this.form.submit();'>
authorSteven Rostedt (VMware) <rostedt@goodmis.org>2017-01-30 19:27:10 -0500
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2017-01-31 09:13:49 -0500
commit79c6f448c8b79c321e4a1f31f98194e4f6b6cae7 (patch)
tree370efda701f03cccf21e02bb1fdd3b852547d75c /net/sctp/output.c
parent0c744ea4f77d72b3dcebb7a8f2684633ec79be88 (diff)
tracing: Fix hwlat kthread migration
The hwlat tracer creates a kernel thread at start of the tracer. It is pinned to a single CPU and will move to the next CPU after each period of running. If the user modifies the migration thread's affinity, it will not change after that happens. The original code created the thread at the first instance it was called, but later was changed to destroy the thread after the tracer was finished, and would not be created until the next instance of the tracer was established. The code that initialized the affinity was only called on the initial instantiation of the tracer. After that, it was not initialized, and the previous affinity did not match the current newly created one, making it appear that the user modified the thread's affinity when it did not, and the thread failed to migrate again. Cc: stable@vger.kernel.org Fixes: 0330f7aa8ee6 ("tracing: Have hwlat trace migrate across tracing_cpumask CPUs") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'net/sctp/output.c')