diff options
author | Michael I. Bushnell <mib@gnu.org> | 1995-07-12 15:42:50 +0000 |
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committer | Michael I. Bushnell <mib@gnu.org> | 1995-07-12 15:42:50 +0000 |
commit | a81cd86c8d93236ffccfbee44b5818ba21523463 (patch) | |
tree | f098368d79e9ed9b39907730c28ed3182b69519d /pfinet/linux-inet/skbuff.c | |
parent | c7923f6aa252a29ccb4f16bd91469c9000a2bd94 (diff) |
entered into RCS
Diffstat (limited to 'pfinet/linux-inet/skbuff.c')
-rw-r--r-- | pfinet/linux-inet/skbuff.c | 573 |
1 files changed, 573 insertions, 0 deletions
diff --git a/pfinet/linux-inet/skbuff.c b/pfinet/linux-inet/skbuff.c new file mode 100644 index 00000000..e4e1d247 --- /dev/null +++ b/pfinet/linux-inet/skbuff.c @@ -0,0 +1,573 @@ +/* + * Routines having to do with the 'struct sk_buff' memory handlers. + * + * Authors: Alan Cox <iiitac@pyr.swan.ac.uk> + * Florian La Roche <rzsfl@rz.uni-sb.de> + * + * Fixes: + * Alan Cox : Fixed the worst of the load balancer bugs. + * Dave Platt : Interrupt stacking fix + * + * This program 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. + */ + +/* + * Note: There are a load of cli()/sti() pairs protecting the net_memory type + * variables. Without them for some reason the ++/-- operators do not come out + * atomic. Also with gcc 2.4.5 these counts can come out wrong anyway - use 2.5.8!! + */ + +#include <linux/config.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <asm/segment.h> +#include <asm/system.h> +#include <linux/mm.h> +#include <linux/interrupt.h> +#include <linux/in.h> +#include <linux/inet.h> +#include <linux/netdevice.h> +#include "ip.h" +#include "protocol.h" +#include <linux/string.h> +#include "route.h" +#include "tcp.h" +#include "udp.h" +#include <linux/skbuff.h> +#include "sock.h" + + +/* + * Resource tracking variables + */ + +volatile unsigned long net_memory = 0; +volatile unsigned long net_skbcount = 0; +volatile unsigned long net_locked = 0; +volatile unsigned long net_allocs = 0; +volatile unsigned long net_fails = 0; +volatile unsigned long net_free_locked = 0; + +void show_net_buffers(void) +{ + printk("Networking buffers in use : %lu\n",net_skbcount); + printk("Memory committed to network buffers: %lu\n",net_memory); + printk("Network buffers locked by drivers : %lu\n",net_locked); + printk("Total network buffer allocations : %lu\n",net_allocs); + printk("Total failed network buffer allocs : %lu\n",net_fails); + printk("Total free while locked events : %lu\n",net_free_locked); +} + +#if CONFIG_SKB_CHECK + +/* + * Debugging paranoia. Can go later when this crud stack works + */ + +int skb_check(struct sk_buff *skb, int head, int line, char *file) +{ + if (head) { + if (skb->magic_debug_cookie != SK_HEAD_SKB) { + printk("File: %s Line %d, found a bad skb-head\n", + file,line); + return -1; + } + if (!skb->next || !skb->prev) { + printk("skb_check: head without next or prev\n"); + return -1; + } + if (skb->next->magic_debug_cookie != SK_HEAD_SKB + && skb->next->magic_debug_cookie != SK_GOOD_SKB) { + printk("File: %s Line %d, bad next head-skb member\n", + file,line); + return -1; + } + if (skb->prev->magic_debug_cookie != SK_HEAD_SKB + && skb->prev->magic_debug_cookie != SK_GOOD_SKB) { + printk("File: %s Line %d, bad prev head-skb member\n", + file,line); + return -1; + } +#if 0 + { + struct sk_buff *skb2 = skb->next; + int i = 0; + while (skb2 != skb && i < 5) { + if (skb_check(skb2, 0, line, file) < 0) { + printk("bad queue element in whole queue\n"); + return -1; + } + i++; + skb2 = skb2->next; + } + } +#endif + return 0; + } + if (skb->next != NULL && skb->next->magic_debug_cookie != SK_HEAD_SKB + && skb->next->magic_debug_cookie != SK_GOOD_SKB) { + printk("File: %s Line %d, bad next skb member\n", + file,line); + return -1; + } + if (skb->prev != NULL && skb->prev->magic_debug_cookie != SK_HEAD_SKB + && skb->prev->magic_debug_cookie != SK_GOOD_SKB) { + printk("File: %s Line %d, bad prev skb member\n", + file,line); + return -1; + } + + + if(skb->magic_debug_cookie==SK_FREED_SKB) + { + printk("File: %s Line %d, found a freed skb lurking in the undergrowth!\n", + file,line); + printk("skb=%p, real size=%ld, claimed size=%ld, free=%d\n", + skb,skb->truesize,skb->mem_len,skb->free); + return -1; + } + if(skb->magic_debug_cookie!=SK_GOOD_SKB) + { + printk("File: %s Line %d, passed a non skb!\n", file,line); + printk("skb=%p, real size=%ld, claimed size=%ld, free=%d\n", + skb,skb->truesize,skb->mem_len,skb->free); + return -1; + } + if(skb->mem_len!=skb->truesize) + { + printk("File: %s Line %d, Dubious size setting!\n",file,line); + printk("skb=%p, real size=%ld, claimed size=%ld\n", + skb,skb->truesize,skb->mem_len); + return -1; + } + /* Guess it might be acceptable then */ + return 0; +} +#endif + + +#ifdef CONFIG_SKB_CHECK +void skb_queue_head_init(struct sk_buff_head *list) +{ + list->prev = (struct sk_buff *)list; + list->next = (struct sk_buff *)list; + list->magic_debug_cookie = SK_HEAD_SKB; +} + + +/* + * Insert an sk_buff at the start of a list. + */ +void skb_queue_head(struct sk_buff_head *list_,struct sk_buff *newsk) +{ + unsigned long flags; + struct sk_buff *list = (struct sk_buff *)list_; + + save_flags(flags); + cli(); + + IS_SKB(newsk); + IS_SKB_HEAD(list); + if (newsk->next || newsk->prev) + printk("Suspicious queue head: sk_buff on list!\n"); + + newsk->next = list->next; + newsk->prev = list; + + newsk->next->prev = newsk; + newsk->prev->next = newsk; + + restore_flags(flags); +} + +/* + * Insert an sk_buff at the end of a list. + */ +void skb_queue_tail(struct sk_buff_head *list_, struct sk_buff *newsk) +{ + unsigned long flags; + struct sk_buff *list = (struct sk_buff *)list_; + + save_flags(flags); + cli(); + + if (newsk->next || newsk->prev) + printk("Suspicious queue tail: sk_buff on list!\n"); + IS_SKB(newsk); + IS_SKB_HEAD(list); + + newsk->next = list; + newsk->prev = list->prev; + + newsk->next->prev = newsk; + newsk->prev->next = newsk; + + restore_flags(flags); +} + +/* + * Remove an sk_buff from a list. This routine is also interrupt safe + * so you can grab read and free buffers as another process adds them. + */ + +struct sk_buff *skb_dequeue(struct sk_buff_head *list_) +{ + long flags; + struct sk_buff *result; + struct sk_buff *list = (struct sk_buff *)list_; + + save_flags(flags); + cli(); + + IS_SKB_HEAD(list); + + result = list->next; + if (result == list) { + restore_flags(flags); + return NULL; + } + + result->next->prev = list; + list->next = result->next; + + result->next = NULL; + result->prev = NULL; + + restore_flags(flags); + + IS_SKB(result); + return result; +} + +/* + * Insert a packet before another one in a list. + */ +void skb_insert(struct sk_buff *old, struct sk_buff *newsk) +{ + unsigned long flags; + + IS_SKB(old); + IS_SKB(newsk); + + if(!old->next || !old->prev) + printk("insert before unlisted item!\n"); + if(newsk->next || newsk->prev) + printk("inserted item is already on a list.\n"); + + save_flags(flags); + cli(); + newsk->next = old; + newsk->prev = old->prev; + old->prev = newsk; + newsk->prev->next = newsk; + + restore_flags(flags); +} + +/* + * Place a packet after a given packet in a list. + */ +void skb_append(struct sk_buff *old, struct sk_buff *newsk) +{ + unsigned long flags; + + IS_SKB(old); + IS_SKB(newsk); + + if(!old->next || !old->prev) + printk("append before unlisted item!\n"); + if(newsk->next || newsk->prev) + printk("append item is already on a list.\n"); + + save_flags(flags); + cli(); + + newsk->prev = old; + newsk->next = old->next; + newsk->next->prev = newsk; + old->next = newsk; + + restore_flags(flags); +} + +/* + * Remove an sk_buff from its list. Works even without knowing the list it + * is sitting on, which can be handy at times. It also means that THE LIST + * MUST EXIST when you unlink. Thus a list must have its contents unlinked + * _FIRST_. + */ +void skb_unlink(struct sk_buff *skb) +{ + unsigned long flags; + + save_flags(flags); + cli(); + + IS_SKB(skb); + + if(skb->prev && skb->next) + { + skb->next->prev = skb->prev; + skb->prev->next = skb->next; + skb->next = NULL; + skb->prev = NULL; + } +#ifdef PARANOID_BUGHUNT_MODE /* This is legal but we sometimes want to watch it */ + else + printk("skb_unlink: not a linked element\n"); +#endif + restore_flags(flags); +} + +#endif + +/* + * Free an sk_buff. This still knows about things it should + * not need to like protocols and sockets. + */ + +void kfree_skb(struct sk_buff *skb, int rw) +{ + if (skb == NULL) + { + printk("kfree_skb: skb = NULL (from %p)\n", + __builtin_return_address(0)); + return; + } +#ifdef CONFIG_SKB_CHECK + IS_SKB(skb); +#endif + if (skb->lock) + { + skb->free = 3; /* Free when unlocked */ + net_free_locked++; + return; + } + if (skb->free == 2) + printk("Warning: kfree_skb passed an skb that nobody set the free flag on! (from %p)\n", + __builtin_return_address(0)); + if (skb->next) + printk("Warning: kfree_skb passed an skb still on a list (from %p).\n", + __builtin_return_address(0)); + if (skb->sk) + { + if(skb->sk->prot!=NULL) + { + if (rw) + skb->sk->prot->rfree(skb->sk, skb, skb->mem_len); + else + skb->sk->prot->wfree(skb->sk, skb, skb->mem_len); + + } + else + { + unsigned long flags; + /* Non INET - default wmalloc/rmalloc handler */ + save_flags(flags); + cli(); + if (rw) + skb->sk->rmem_alloc-=skb->mem_len; + else + skb->sk->wmem_alloc-=skb->mem_len; + restore_flags(flags); + if(!skb->sk->dead) + skb->sk->write_space(skb->sk); + kfree_skbmem(skb,skb->mem_len); + } + } + else + kfree_skbmem(skb, skb->mem_len); +} + +/* + * Allocate a new skbuff. We do this ourselves so we can fill in a few 'private' + * fields and also do memory statistics to find all the [BEEP] leaks. + */ +struct sk_buff *alloc_skb(unsigned int size,int priority) +{ + struct sk_buff *skb; + unsigned long flags; + + if (intr_count && priority!=GFP_ATOMIC) { + static int count = 0; + if (++count < 5) { + printk("alloc_skb called nonatomically from interrupt %p\n", + __builtin_return_address(0)); + priority = GFP_ATOMIC; + } + } + + size+=sizeof(struct sk_buff); + skb=(struct sk_buff *)kmalloc(size,priority); + if (skb == NULL) + { + net_fails++; + return NULL; + } +#ifdef PARANOID_BUGHUNT_MODE + if(skb->magic_debug_cookie == SK_GOOD_SKB) + printk("Kernel kmalloc handed us an existing skb (%p)\n",skb); +#endif + + net_allocs++; + + skb->free = 2; /* Invalid so we pick up forgetful users */ + skb->lock = 0; + skb->pkt_type = PACKET_HOST; /* Default type */ + skb->truesize = size; + skb->mem_len = size; + skb->mem_addr = skb; +#ifdef CONFIG_SLAVE_BALANCING + skb->in_dev_queue = 0; +#endif + skb->fraglist = NULL; + skb->prev = skb->next = NULL; + skb->link3 = NULL; + skb->sk = NULL; + skb->localroute=0; + skb->stamp.tv_sec=0; /* No idea about time */ + skb->localroute = 0; + save_flags(flags); + cli(); + net_memory += size; + net_skbcount++; + restore_flags(flags); +#if CONFIG_SKB_CHECK + skb->magic_debug_cookie = SK_GOOD_SKB; +#endif + skb->users = 0; + return skb; +} + +/* + * Free an skbuff by memory + */ + +void kfree_skbmem(struct sk_buff *skb,unsigned size) +{ + unsigned long flags; +#ifdef CONFIG_SLAVE_BALANCING + save_flags(flags); + cli(); + if(skb->in_dev_queue && skb->dev!=NULL) + skb->dev->pkt_queue--; + restore_flags(flags); +#endif +#ifdef CONFIG_SKB_CHECK + IS_SKB(skb); + if(size!=skb->truesize) + printk("kfree_skbmem: size mismatch.\n"); + + if(skb->magic_debug_cookie == SK_GOOD_SKB) + { + save_flags(flags); + cli(); + IS_SKB(skb); + skb->magic_debug_cookie = SK_FREED_SKB; + kfree_s((void *)skb,size); + net_skbcount--; + net_memory -= size; + restore_flags(flags); + } + else + printk("kfree_skbmem: bad magic cookie\n"); +#else + save_flags(flags); + cli(); + kfree_s((void *)skb,size); + net_skbcount--; + net_memory -= size; + restore_flags(flags); +#endif +} + +/* + * Duplicate an sk_buff. The new one is not owned by a socket or locked + * and will be freed on deletion. + */ + +struct sk_buff *skb_clone(struct sk_buff *skb, int priority) +{ + struct sk_buff *n; + unsigned long offset; + + n=alloc_skb(skb->mem_len-sizeof(struct sk_buff),priority); + if(n==NULL) + return NULL; + + offset=((char *)n)-((char *)skb); + + memcpy(n->data,skb->data,skb->mem_len-sizeof(struct sk_buff)); + n->len=skb->len; + n->link3=NULL; + n->sk=NULL; + n->when=skb->when; + n->dev=skb->dev; + n->h.raw=skb->h.raw+offset; + n->ip_hdr=(struct iphdr *)(((char *)skb->ip_hdr)+offset); + n->fraglen=skb->fraglen; + n->fraglist=skb->fraglist; + n->saddr=skb->saddr; + n->daddr=skb->daddr; + n->raddr=skb->raddr; + n->acked=skb->acked; + n->used=skb->used; + n->free=1; + n->arp=skb->arp; + n->tries=0; + n->lock=0; + n->users=0; + n->pkt_type=skb->pkt_type; + return n; +} + + +/* + * Skbuff device locking + */ + +void skb_device_lock(struct sk_buff *skb) +{ + if(skb->lock) + printk("double lock on device queue!\n"); + else + net_locked++; + skb->lock++; +} + +void skb_device_unlock(struct sk_buff *skb) +{ + if(skb->lock==0) + printk("double unlock on device queue!\n"); + skb->lock--; + if(skb->lock==0) + net_locked--; +} + +void dev_kfree_skb(struct sk_buff *skb, int mode) +{ + unsigned long flags; + + save_flags(flags); + cli(); + if(skb->lock==1) + net_locked--; + + if (!--skb->lock && (skb->free == 1 || skb->free == 3)) + { + restore_flags(flags); + kfree_skb(skb,mode); + } + else + restore_flags(flags); +} + +int skb_device_locked(struct sk_buff *skb) +{ + return skb->lock? 1 : 0; +} + |