net/atm/addr.c

   1 /* net/atm/addr.c - Local ATM address registry */
   2
   3 /* Written 1995-1999 by Werner Almesberger, EPFL LRC/ICA */
   4
   5
   6 #include <linux/atm.h>
   7 #include <linux/atmdev.h>
   8 #include <linux/wait.h>
   9 #include <asm/uaccess.h>
  10
  11 #include "signaling.h"
  12 #include "addr.h"
  13
  14
  15 static int check_addr(struct sockaddr_atmsvc *addr)
  16 {
  17         int i;
  18
  19         if (addr->sas_family != AF_ATMSVC) return -EAFNOSUPPORT;
  20         if (!*addr->sas_addr.pub)
  21                 return *addr->sas_addr.prv ? 0 : -EINVAL;
  22         for (i = 1; i < ATM_E164_LEN+1; i++) /* make sure it's \0-terminated */
  23                 if (!addr->sas_addr.pub[i]) return 0;
  24         return -EINVAL;
  25 }
  26
  27
  28 static int identical(struct sockaddr_atmsvc *a,struct sockaddr_atmsvc *b)
  29 {
  30         if (*a->sas_addr.prv)
  31                 if (memcmp(a->sas_addr.prv,b->sas_addr.prv,ATM_ESA_LEN))
  32                         return 0;
  33         if (!*a->sas_addr.pub) return !*b->sas_addr.pub;
  34         if (!*b->sas_addr.pub) return 0;
  35         return !strcmp(a->sas_addr.pub,b->sas_addr.pub);
  36 }
  37
  38
  39 /*
  40  * Avoid modification of any list of local interfaces while reading it
  41  * (which may involve page faults and therefore rescheduling)
  42  */
  43
  44
  45 static volatile int local_lock = 0;
  46 static wait_queue_head_t local_wait;
  47
  48
  49 static void lock_local(void)
  50 {
  51         while (local_lock) sleep_on(&local_wait);
  52         local_lock = 1;
  53 }
  54
  55
  56 static void unlock_local(void)
  57 {
  58         local_lock = 0;
  59         wake_up(&local_wait);
  60 }
  61
  62
  63 static void notify_sigd(struct atm_dev *dev)
  64 {
  65         struct sockaddr_atmpvc pvc;
  66
  67         pvc.sap_addr.itf = dev->number;
  68         sigd_enq(NULL,as_itf_notify,NULL,&pvc,NULL);
  69 }
  70
  71
  72 void reset_addr(struct atm_dev *dev)
  73 {
  74         struct atm_dev_addr *this;
  75
  76         lock_local();
  77         while (dev->local) {
  78                 this = dev->local;
  79                 dev->local = this->next;
  80                 kfree(this);
  81         }
  82         unlock_local();
  83         notify_sigd(dev);
  84 }
  85
  86
  87 int add_addr(struct atm_dev *dev,struct sockaddr_atmsvc *addr)
  88 {
  89         struct atm_dev_addr **walk;
  90         int error;
  91
  92         error = check_addr(addr);
  93         if (error) return error;
  94         lock_local();
  95         for (walk = &dev->local; *walk; walk = &(*walk)->next)
  96                 if (identical(&(*walk)->addr,addr)) {
  97                         unlock_local();
  98                         return -EEXIST;
  99                 }
 100         *walk = kmalloc(sizeof(struct atm_dev_addr),GFP_KERNEL);
 101         if (!*walk) {
 102                 unlock_local();
 103                 return -ENOMEM;
 104         }
 105         (*walk)->addr = *addr;
 106         (*walk)->next = NULL;
 107         unlock_local();
 108         notify_sigd(dev);
 109         return 0;
 110 }
 111
 112
 113 int del_addr(struct atm_dev *dev,struct sockaddr_atmsvc *addr)
 114 {
 115         struct atm_dev_addr **walk,*this;
 116         int error;
 117
 118         error = check_addr(addr);
 119         if (error) return error;
 120         lock_local();
 121         for (walk = &dev->local; *walk; walk = &(*walk)->next)
 122                 if (identical(&(*walk)->addr,addr)) break;
 123         if (!*walk) {
 124                 unlock_local();
 125                 return -ENOENT;
 126         }
 127         this = *walk;
 128         *walk = this->next;
 129         kfree(this);
 130         unlock_local();
 131         notify_sigd(dev);
 132         return 0;
 133 }
 134
 135
 136 int get_addr(struct atm_dev *dev,struct sockaddr_atmsvc *u_buf,int size)
 137 {
 138         struct atm_dev_addr *walk;
 139         int total;
 140
 141         lock_local();
 142         total = 0;
 143         for (walk = dev->local; walk; walk = walk->next) {
 144                 total += sizeof(struct sockaddr_atmsvc);
 145                 if (total > size) {
 146                         unlock_local();
 147                         return -E2BIG;
 148                 }
 149                 if (copy_to_user(u_buf,&walk->addr,
 150                     sizeof(struct sockaddr_atmsvc))) {
 151                         unlock_local();
 152                         return -EFAULT;
 153                 }
 154                 u_buf++;
 155         }
 156         unlock_local();
 157         return total;
 158 }
 159
 160
 161 void init_addr(void)
 162 {
 163         init_waitqueue_head(&local_wait);
 164 }