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Diffstat (limited to 'net/x25/x25_facilities.c')
-rw-r--r--net/x25/x25_facilities.c89
1 files changed, 66 insertions, 23 deletions
diff --git a/net/x25/x25_facilities.c b/net/x25/x25_facilities.c
index a21f6646eb3..7ecd04c2136 100644
--- a/net/x25/x25_facilities.c
+++ b/net/x25/x25_facilities.c
@@ -21,21 +21,33 @@
* on response.
*/
+#define pr_fmt(fmt) "X25: " fmt
+
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <net/x25.h>
-/*
- * Parse a set of facilities into the facilities structures. Unrecognised
- * facilities are written to the debug log file.
+/**
+ * x25_parse_facilities - Parse facilities from skb into the facilities structs
+ *
+ * @skb: sk_buff to parse
+ * @facilities: Regular facilities, updated as facilities are found
+ * @dte_facs: ITU DTE facilities, updated as DTE facilities are found
+ * @vc_fac_mask: mask is updated with all facilities found
+ *
+ * Return codes:
+ * -1 - Parsing error, caller should drop call and clean up
+ * 0 - Parse OK, this skb has no facilities
+ * >0 - Parse OK, returns the length of the facilities header
+ *
*/
int x25_parse_facilities(struct sk_buff *skb, struct x25_facilities *facilities,
struct x25_dte_facilities *dte_facs, unsigned long *vc_fac_mask)
{
- unsigned char *p = skb->data;
- unsigned int len = *p++;
+ unsigned char *p;
+ unsigned int len;
*vc_fac_mask = 0;
@@ -50,9 +62,21 @@ int x25_parse_facilities(struct sk_buff *skb, struct x25_facilities *facilities,
memset(dte_facs->called_ae, '\0', sizeof(dte_facs->called_ae));
memset(dte_facs->calling_ae, '\0', sizeof(dte_facs->calling_ae));
+ if (!pskb_may_pull(skb, 1))
+ return 0;
+
+ len = skb->data[0];
+
+ if (!pskb_may_pull(skb, 1 + len))
+ return -1;
+
+ p = skb->data + 1;
+
while (len > 0) {
switch (*p & X25_FAC_CLASS_MASK) {
case X25_FAC_CLASS_A:
+ if (len < 2)
+ return -1;
switch (*p) {
case X25_FAC_REVERSE:
if((p[1] & 0x81) == 0x81) {
@@ -87,7 +111,7 @@ int x25_parse_facilities(struct sk_buff *skb, struct x25_facilities *facilities,
case X25_MARKER:
break;
default:
- printk(KERN_DEBUG "X.25: unknown facility "
+ pr_debug("unknown facility "
"%02X, value %02X\n",
p[0], p[1]);
break;
@@ -96,6 +120,8 @@ int x25_parse_facilities(struct sk_buff *skb, struct x25_facilities *facilities,
len -= 2;
break;
case X25_FAC_CLASS_B:
+ if (len < 3)
+ return -1;
switch (*p) {
case X25_FAC_PACKET_SIZE:
facilities->pacsize_in = p[1];
@@ -108,7 +134,7 @@ int x25_parse_facilities(struct sk_buff *skb, struct x25_facilities *facilities,
*vc_fac_mask |= X25_MASK_WINDOW_SIZE;
break;
default:
- printk(KERN_DEBUG "X.25: unknown facility "
+ pr_debug("unknown facility "
"%02X, values %02X, %02X\n",
p[0], p[1], p[2]);
break;
@@ -117,33 +143,39 @@ int x25_parse_facilities(struct sk_buff *skb, struct x25_facilities *facilities,
len -= 3;
break;
case X25_FAC_CLASS_C:
- printk(KERN_DEBUG "X.25: unknown facility %02X, "
+ if (len < 4)
+ return -1;
+ pr_debug("unknown facility %02X, "
"values %02X, %02X, %02X\n",
p[0], p[1], p[2], p[3]);
p += 4;
len -= 4;
break;
case X25_FAC_CLASS_D:
+ if (len < p[1] + 2)
+ return -1;
switch (*p) {
case X25_FAC_CALLING_AE:
- if (p[1] > X25_MAX_DTE_FACIL_LEN)
- break;
+ if (p[1] > X25_MAX_DTE_FACIL_LEN || p[1] <= 1)
+ return -1;
+ if (p[2] > X25_MAX_AE_LEN)
+ return -1;
dte_facs->calling_len = p[2];
memcpy(dte_facs->calling_ae, &p[3], p[1] - 1);
*vc_fac_mask |= X25_MASK_CALLING_AE;
break;
case X25_FAC_CALLED_AE:
- if (p[1] > X25_MAX_DTE_FACIL_LEN)
- break;
+ if (p[1] > X25_MAX_DTE_FACIL_LEN || p[1] <= 1)
+ return -1;
+ if (p[2] > X25_MAX_AE_LEN)
+ return -1;
dte_facs->called_len = p[2];
memcpy(dte_facs->called_ae, &p[3], p[1] - 1);
*vc_fac_mask |= X25_MASK_CALLED_AE;
break;
default:
- printk(KERN_DEBUG "X.25: unknown facility %02X,"
- "length %d, values %02X, %02X, "
- "%02X, %02X\n",
- p[0], p[1], p[2], p[3], p[4], p[5]);
+ pr_debug("unknown facility %02X,"
+ "length %d\n", p[0], p[1]);
break;
}
len -= p[1] + 2;
@@ -205,7 +237,7 @@ int x25_create_facilities(unsigned char *buffer,
}
if (dte_facs->calling_len && (facil_mask & X25_MASK_CALLING_AE)) {
- unsigned bytecount = (dte_facs->calling_len + 1) >> 1;
+ unsigned int bytecount = (dte_facs->calling_len + 1) >> 1;
*p++ = X25_FAC_CALLING_AE;
*p++ = 1 + bytecount;
*p++ = dte_facs->calling_len;
@@ -214,7 +246,7 @@ int x25_create_facilities(unsigned char *buffer,
}
if (dte_facs->called_len && (facil_mask & X25_MASK_CALLED_AE)) {
- unsigned bytecount = (dte_facs->called_len % 2) ?
+ unsigned int bytecount = (dte_facs->called_len % 2) ?
dte_facs->called_len / 2 + 1 :
dte_facs->called_len / 2;
*p++ = X25_FAC_CALLED_AE;
@@ -247,6 +279,8 @@ int x25_negotiate_facilities(struct sk_buff *skb, struct sock *sk,
memcpy(new, ours, sizeof(*new));
len = x25_parse_facilities(skb, &theirs, dte, &x25->vc_facil_mask);
+ if (len < 0)
+ return len;
/*
* They want reverse charging, we won't accept it.
@@ -259,9 +293,18 @@ int x25_negotiate_facilities(struct sk_buff *skb, struct sock *sk,
new->reverse = theirs.reverse;
if (theirs.throughput) {
- if (theirs.throughput < ours->throughput) {
- SOCK_DEBUG(sk, "X.25: throughput negotiated down\n");
- new->throughput = theirs.throughput;
+ int theirs_in = theirs.throughput & 0x0f;
+ int theirs_out = theirs.throughput & 0xf0;
+ int ours_in = ours->throughput & 0x0f;
+ int ours_out = ours->throughput & 0xf0;
+ if (!ours_in || theirs_in < ours_in) {
+ SOCK_DEBUG(sk, "X.25: inbound throughput negotiated\n");
+ new->throughput = (new->throughput & 0xf0) | theirs_in;
+ }
+ if (!ours_out || theirs_out < ours_out) {
+ SOCK_DEBUG(sk,
+ "X.25: outbound throughput negotiated\n");
+ new->throughput = (new->throughput & 0x0f) | theirs_out;
}
}
@@ -300,12 +343,12 @@ void x25_limit_facilities(struct x25_facilities *facilities,
if (!nb->extended) {
if (facilities->winsize_in > 7) {
- printk(KERN_DEBUG "X.25: incoming winsize limited to 7\n");
+ pr_debug("incoming winsize limited to 7\n");
facilities->winsize_in = 7;
}
if (facilities->winsize_out > 7) {
facilities->winsize_out = 7;
- printk( KERN_DEBUG "X.25: outgoing winsize limited to 7\n");
+ pr_debug("outgoing winsize limited to 7\n");
}
}
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-12-06 00:15:55 +0000