diff options
Diffstat (limited to 'net/x25')
-rw-r--r-- | net/x25/af_x25.c | 67 | ||||
-rw-r--r-- | net/x25/x25_facilities.c | 27 | ||||
-rw-r--r-- | net/x25/x25_in.c | 15 |
3 files changed, 96 insertions, 13 deletions
diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c index e56f711bacc..cbddd0cb83f 100644 --- a/net/x25/af_x25.c +++ b/net/x25/af_x25.c @@ -83,6 +83,41 @@ struct compat_x25_subscrip_struct { }; #endif + +int x25_parse_address_block(struct sk_buff *skb, + struct x25_address *called_addr, + struct x25_address *calling_addr) +{ + unsigned char len; + int needed; + int rc; + + if (skb->len < 1) { + /* packet has no address block */ + rc = 0; + goto empty; + } + + len = *skb->data; + needed = 1 + (len >> 4) + (len & 0x0f); + + if (skb->len < needed) { + /* packet is too short to hold the addresses it claims + to hold */ + rc = -1; + goto empty; + } + + return x25_addr_ntoa(skb->data, called_addr, calling_addr); + +empty: + *called_addr->x25_addr = 0; + *calling_addr->x25_addr = 0; + + return rc; +} + + int x25_addr_ntoa(unsigned char *p, struct x25_address *called_addr, struct x25_address *calling_addr) { @@ -554,7 +589,8 @@ static int x25_create(struct net *net, struct socket *sock, int protocol, x25->facilities.winsize_out = X25_DEFAULT_WINDOW_SIZE; x25->facilities.pacsize_in = X25_DEFAULT_PACKET_SIZE; x25->facilities.pacsize_out = X25_DEFAULT_PACKET_SIZE; - x25->facilities.throughput = X25_DEFAULT_THROUGHPUT; + x25->facilities.throughput = 0; /* by default don't negotiate + throughput */ x25->facilities.reverse = X25_DEFAULT_REVERSE; x25->dte_facilities.calling_len = 0; x25->dte_facilities.called_len = 0; @@ -922,16 +958,26 @@ int x25_rx_call_request(struct sk_buff *skb, struct x25_neigh *nb, /* * Extract the X.25 addresses and convert them to ASCII strings, * and remove them. + * + * Address block is mandatory in call request packets */ - addr_len = x25_addr_ntoa(skb->data, &source_addr, &dest_addr); + addr_len = x25_parse_address_block(skb, &source_addr, &dest_addr); + if (addr_len <= 0) + goto out_clear_request; skb_pull(skb, addr_len); /* * Get the length of the facilities, skip past them for the moment * get the call user data because this is needed to determine * the correct listener + * + * Facilities length is mandatory in call request packets */ + if (skb->len < 1) + goto out_clear_request; len = skb->data[0] + 1; + if (skb->len < len) + goto out_clear_request; skb_pull(skb,len); /* @@ -1415,9 +1461,20 @@ static int x25_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) if (facilities.winsize_in < 1 || facilities.winsize_in > 127) break; - if (facilities.throughput < 0x03 || - facilities.throughput > 0xDD) - break; + if (facilities.throughput) { + int out = facilities.throughput & 0xf0; + int in = facilities.throughput & 0x0f; + if (!out) + facilities.throughput |= + X25_DEFAULT_THROUGHPUT << 4; + else if (out < 0x30 || out > 0xD0) + break; + if (!in) + facilities.throughput |= + X25_DEFAULT_THROUGHPUT; + else if (in < 0x03 || in > 0x0D) + break; + } if (facilities.reverse && (facilities.reverse & 0x81) != 0x81) break; diff --git a/net/x25/x25_facilities.c b/net/x25/x25_facilities.c index a21f6646eb3..771bab00754 100644 --- a/net/x25/x25_facilities.c +++ b/net/x25/x25_facilities.c @@ -35,7 +35,7 @@ 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 int len; *vc_fac_mask = 0; @@ -50,6 +50,14 @@ 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 (skb->len < 1) + return 0; + + len = *p++; + + if (len >= skb->len) + return -1; + while (len > 0) { switch (*p & X25_FAC_CLASS_MASK) { case X25_FAC_CLASS_A: @@ -247,6 +255,8 @@ 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 +269,18 @@ 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; } } diff --git a/net/x25/x25_in.c b/net/x25/x25_in.c index a31b3b9e596..372ac226e64 100644 --- a/net/x25/x25_in.c +++ b/net/x25/x25_in.c @@ -90,6 +90,7 @@ static int x25_queue_rx_frame(struct sock *sk, struct sk_buff *skb, int more) static int x25_state1_machine(struct sock *sk, struct sk_buff *skb, int frametype) { struct x25_address source_addr, dest_addr; + int len; switch (frametype) { case X25_CALL_ACCEPTED: { @@ -107,11 +108,17 @@ static int x25_state1_machine(struct sock *sk, struct sk_buff *skb, int frametyp * Parse the data in the frame. */ skb_pull(skb, X25_STD_MIN_LEN); - skb_pull(skb, x25_addr_ntoa(skb->data, &source_addr, &dest_addr)); - skb_pull(skb, - x25_parse_facilities(skb, &x25->facilities, + + len = x25_parse_address_block(skb, &source_addr, + &dest_addr); + if (len > 0) + skb_pull(skb, len); + + len = x25_parse_facilities(skb, &x25->facilities, &x25->dte_facilities, - &x25->vc_facil_mask)); + &x25->vc_facil_mask); + if (len > 0) + skb_pull(skb, len); /* * Copy any Call User Data. */ |