cregit-Linux how code gets into the kernel

Release 4.14 drivers/isdn/i4l/isdn_x25iface.c

Directory: drivers/isdn/i4l
/* $Id: isdn_x25iface.c,v 1.1.2.2 2004/01/12 22:37:19 keil Exp $
 *
 * Linux ISDN subsystem, X.25 related functions
 *
 * This software may be used and distributed according to the terms
 * of the GNU General Public License, incorporated herein by reference.
 *
 * stuff needed to support the Linux X.25 PLP code on top of devices that
 * can provide a lab_b service using the concap_proto mechanism.
 * This module supports a network interface which provides lapb_sematics
 * -- as defined in Documentation/networking/x25-iface.txt -- to
 * the upper layer and assumes that the lower layer provides a reliable
 * data link service by means of the concap_device_ops callbacks.
 *
 * Only protocol specific stuff goes here. Device specific stuff
 * goes to another -- device related -- concap_proto support source file.
 *
 */

/* #include <linux/isdn.h> */
#include <linux/netdevice.h>
#include <linux/concap.h>
#include <linux/slab.h>
#include <linux/wanrouter.h>
#include <net/x25device.h>
#include "isdn_x25iface.h"

/* for debugging messages not to cause an oops when device pointer is NULL*/

#define MY_DEVNAME(dev)  ((dev) ? (dev)->name : "DEVICE UNSPECIFIED")



typedef struct isdn_x25iface_proto_data {
	
int magic;
	
enum wan_states state;
	/* Private stuff, not to be accessed via proto_data. We provide the
           other storage for the concap_proto instance here as well,
           enabling us to allocate both with just one kmalloc(): */
	
struct concap_proto priv;

} ix25_pdata_t;



/* is now in header file (extern): struct concap_proto * isdn_x25iface_proto_new(void); */
static void isdn_x25iface_proto_del(struct concap_proto *);
static int isdn_x25iface_proto_close(struct concap_proto *);
static int isdn_x25iface_proto_restart(struct concap_proto *,
				       struct net_device *,
				       struct concap_device_ops *);
static int isdn_x25iface_xmit(struct concap_proto *, struct sk_buff *);
static int isdn_x25iface_receive(struct concap_proto *, struct sk_buff *);
static int isdn_x25iface_connect_ind(struct concap_proto *);
static int isdn_x25iface_disconn_ind(struct concap_proto *);



static struct concap_proto_ops ix25_pops = {
	.proto_new = &isdn_x25iface_proto_new,
	.proto_del = &isdn_x25iface_proto_del,
	.restart = &isdn_x25iface_proto_restart,
	.close = &isdn_x25iface_proto_close,
	.encap_and_xmit = &isdn_x25iface_xmit,
	.data_ind = &isdn_x25iface_receive,
	.connect_ind = &isdn_x25iface_connect_ind,
	.disconn_ind = &isdn_x25iface_disconn_ind
};

/* error message helper function */

static void illegal_state_warn(unsigned state, unsigned char firstbyte) { printk(KERN_WARNING "isdn_x25iface: firstbyte %x illegal in" "current state %d\n", firstbyte, state); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)2395.83%150.00%
Andrew Morton14.17%150.00%
Total24100.00%2100.00%

/* check protocol data field for consistency */
static int pdata_is_bad(ix25_pdata_t *pda) { if (pda && pda->magic == ISDN_X25IFACE_MAGIC) return 0; printk(KERN_WARNING "isdn_x25iface_xxx: illegal pointer to proto data\n"); return 1; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)3196.88%150.00%
Andrew Morton13.12%150.00%
Total32100.00%2100.00%

/* create a new x25 interface protocol instance */
struct concap_proto *isdn_x25iface_proto_new(void) { ix25_pdata_t *tmp = kmalloc(sizeof(ix25_pdata_t), GFP_KERNEL); IX25DEBUG("isdn_x25iface_proto_new\n"); if (tmp) { tmp->magic = ISDN_X25IFACE_MAGIC; tmp->state = WAN_UNCONFIGURED; /* private data space used to hold the concap_proto data. Only to be accessed via the returned pointer */ spin_lock_init(&tmp->priv.lock); tmp->priv.dops = NULL; tmp->priv.net_dev = NULL; tmp->priv.pops = &ix25_pops; tmp->priv.flags = 0; tmp->priv.proto_data = tmp; return (&(tmp->priv)); } return NULL; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)9888.29%133.33%
Andrew Morton109.01%133.33%
Al Viro32.70%133.33%
Total111100.00%3100.00%

; /* close the x25iface encapsulation protocol */
static int isdn_x25iface_proto_close(struct concap_proto *cprot) { ix25_pdata_t *tmp; int ret = 0; ulong flags; if (!cprot) { printk(KERN_ERR "isdn_x25iface_proto_close: " "invalid concap_proto pointer\n"); return -1; } IX25DEBUG("isdn_x25iface_proto_close %s \n", MY_DEVNAME(cprot->net_dev)); spin_lock_irqsave(&cprot->lock, flags); cprot->dops = NULL; cprot->net_dev = NULL; tmp = cprot->proto_data; if (pdata_is_bad(tmp)) { ret = -1; } else { tmp->state = WAN_UNCONFIGURED; } spin_unlock_irqrestore(&cprot->lock, flags); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)10488.89%133.33%
Andrew Morton1210.26%133.33%
Adrian Bunk10.85%133.33%
Total117100.00%3100.00%

/* Delete the x25iface encapsulation protocol instance */
static void isdn_x25iface_proto_del(struct concap_proto *cprot) { ix25_pdata_t *tmp; IX25DEBUG("isdn_x25iface_proto_del \n"); if (!cprot) { printk(KERN_ERR "isdn_x25iface_proto_del: " "concap_proto pointer is NULL\n"); return; } tmp = cprot->proto_data; if (tmp == NULL) { printk(KERN_ERR "isdn_x25iface_proto_del: inconsistent " "proto_data pointer (maybe already deleted?)\n"); return; } /* close if the protocol is still open */ if (cprot->dops) isdn_x25iface_proto_close(cprot); /* freeing the storage should be sufficient now. But some additional settings might help to catch wild pointer bugs */ tmp->magic = 0; cprot->proto_data = NULL; kfree(tmp); return; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)8798.86%150.00%
Adrian Bunk11.14%150.00%
Total88100.00%2100.00%

/* (re-)initialize the data structures for x25iface encapsulation */
static int isdn_x25iface_proto_restart(struct concap_proto *cprot, struct net_device *ndev, struct concap_device_ops *dops) { ix25_pdata_t *pda = cprot->proto_data; ulong flags; IX25DEBUG("isdn_x25iface_proto_restart %s \n", MY_DEVNAME(ndev)); if (pdata_is_bad(pda)) return -1; if (!(dops && dops->data_req && dops->connect_req && dops->disconn_req)) { printk(KERN_WARNING "isdn_x25iface_restart: required dops" " missing\n"); isdn_x25iface_proto_close(cprot); return -1; } spin_lock_irqsave(&cprot->lock, flags); cprot->net_dev = ndev; cprot->pops = &ix25_pops; cprot->dops = dops; pda->state = WAN_DISCONNECTED; spin_unlock_irqrestore(&cprot->lock, flags); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)12590.58%250.00%
Andrew Morton128.70%125.00%
Adrian Bunk10.72%125.00%
Total138100.00%4100.00%

/* deliver a dl_data frame received from i4l HL driver to the network layer */
static int isdn_x25iface_receive(struct concap_proto *cprot, struct sk_buff *skb) { IX25DEBUG("isdn_x25iface_receive %s \n", MY_DEVNAME(cprot->net_dev)); if (((ix25_pdata_t *)(cprot->proto_data)) ->state == WAN_CONNECTED) { if (skb_push(skb, 1)) { skb->data[0] = X25_IFACE_DATA; skb->protocol = x25_type_trans(skb, cprot->net_dev); netif_rx(skb); return 0; } } printk(KERN_WARNING "isdn_x25iface_receive %s: not connected, skb dropped\n", MY_DEVNAME(cprot->net_dev)); dev_kfree_skb(skb); return -1; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)10291.89%125.00%
Arnaldo Carvalho de Melo76.31%125.00%
Andrew Hendry10.90%125.00%
Adrian Bunk10.90%125.00%
Total111100.00%4100.00%

/* a connection set up is indicated by lower layer */
static int isdn_x25iface_connect_ind(struct concap_proto *cprot) { struct sk_buff *skb; enum wan_states *state_p = &(((ix25_pdata_t *)(cprot->proto_data))->state); IX25DEBUG("isdn_x25iface_connect_ind %s \n" , MY_DEVNAME(cprot->net_dev)); if (*state_p == WAN_UNCONFIGURED) { printk(KERN_WARNING "isdn_x25iface_connect_ind while unconfigured %s\n" , MY_DEVNAME(cprot->net_dev)); return -1; } *state_p = WAN_CONNECTED; skb = dev_alloc_skb(1); if (skb) { skb_put_u8(skb, X25_IFACE_CONNECT); skb->protocol = x25_type_trans(skb, cprot->net_dev); netif_rx(skb); return 0; } else { printk(KERN_WARNING "isdn_x25iface_connect_ind: " " out of memory -- disconnecting\n"); cprot->dops->disconn_req(cprot); return -1; } }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)13089.66%116.67%
Eric Sesterhenn / Snakebyte74.83%116.67%
Arnaldo Carvalho de Melo42.76%116.67%
Johannes Berg21.38%116.67%
Andrew Hendry10.69%116.67%
Adrian Bunk10.69%116.67%
Total145100.00%6100.00%

/* a disconnect is indicated by lower layer */
static int isdn_x25iface_disconn_ind(struct concap_proto *cprot) { struct sk_buff *skb; enum wan_states *state_p = &(((ix25_pdata_t *)(cprot->proto_data))->state); IX25DEBUG("isdn_x25iface_disconn_ind %s \n", MY_DEVNAME(cprot->net_dev)); if (*state_p == WAN_UNCONFIGURED) { printk(KERN_WARNING "isdn_x25iface_disconn_ind while unconfigured\n"); return -1; } if (!cprot->net_dev) return -1; *state_p = WAN_DISCONNECTED; skb = dev_alloc_skb(1); if (skb) { skb_put_u8(skb, X25_IFACE_DISCONNECT); skb->protocol = x25_type_trans(skb, cprot->net_dev); netif_rx(skb); return 0; } else { printk(KERN_WARNING "isdn_x25iface_disconn_ind:" " out of memory\n"); return -1; } }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)13294.29%120.00%
Arnaldo Carvalho de Melo42.86%120.00%
Johannes Berg21.43%120.00%
Adrian Bunk10.71%120.00%
Andrew Hendry10.71%120.00%
Total140100.00%5100.00%

/* process a frame handed over to us from linux network layer. First byte semantics as defined in Documentation/networking/x25-iface.txt */
static int isdn_x25iface_xmit(struct concap_proto *cprot, struct sk_buff *skb) { unsigned char firstbyte = skb->data[0]; enum wan_states *state = &((ix25_pdata_t *)cprot->proto_data)->state; int ret = 0; IX25DEBUG("isdn_x25iface_xmit: %s first=%x state=%d\n", MY_DEVNAME(cprot->net_dev), firstbyte, *state); switch (firstbyte) { case X25_IFACE_DATA: if (*state == WAN_CONNECTED) { skb_pull(skb, 1); netif_trans_update(cprot->net_dev); ret = (cprot->dops->data_req(cprot, skb)); /* prepare for future retransmissions */ if (ret) skb_push(skb, 1); return ret; } illegal_state_warn(*state, firstbyte); break; case X25_IFACE_CONNECT: if (*state == WAN_DISCONNECTED) { *state = WAN_CONNECTING; ret = cprot->dops->connect_req(cprot); if (ret) { /* reset state and notify upper layer about * immidiatly failed attempts */ isdn_x25iface_disconn_ind(cprot); } } else { illegal_state_warn(*state, firstbyte); } break; case X25_IFACE_DISCONNECT: switch (*state) { case WAN_DISCONNECTED: /* Should not happen. However, give upper layer a chance to recover from inconstistency but don't trust the lower layer sending the disconn_confirm when already disconnected */ printk(KERN_WARNING "isdn_x25iface_xmit: disconnect " " requested while disconnected\n"); isdn_x25iface_disconn_ind(cprot); break; /* prevent infinite loops */ case WAN_CONNECTING: case WAN_CONNECTED: *state = WAN_DISCONNECTED; cprot->dops->disconn_req(cprot); break; default: illegal_state_warn(*state, firstbyte); } break; case X25_IFACE_PARAMS: printk(KERN_WARNING "isdn_x25iface_xmit: setting of lapb" " options not yet supported\n"); break; default: printk(KERN_WARNING "isdn_x25iface_xmit: frame with illegal" " first byte %x ignored:\n", firstbyte); } dev_kfree_skb(skb); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)26695.68%228.57%
Andrew Hendry51.80%114.29%
Florian Westphal31.08%114.29%
Al Viro20.72%114.29%
Adrian Bunk10.36%114.29%
Andrew Morton10.36%114.29%
Total278100.00%7100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)124690.49%425.00%
Andrew Morton382.76%16.25%
Kees Cook241.74%16.25%
Arnaldo Carvalho de Melo181.31%16.25%
Adrian Bunk141.02%16.25%
Andrew Hendry80.58%16.25%
Eric Sesterhenn / Snakebyte70.51%16.25%
Joe Perches60.44%16.25%
Al Viro50.36%16.25%
Johannes Berg40.29%16.25%
Tejun Heo30.22%16.25%
Florian Westphal30.22%16.25%
Uwe Zeisberger (is this really Uwe?)10.07%16.25%
Total1377100.00%16100.00%
Directory: drivers/isdn/i4l
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