[PATCH] ppp: set address and control field

[PATCH] ppp: set address and control field

[Kristen Carlson Accardi]

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Before sending to hdlc, set the address and control field.
Fix hardcode of ppp header size.
---
 gatchat/gatppp.c   |    9 +++++++--
 gatchat/ppp.h      |    4 ++++
 gatchat/ppp_auth.c |    2 +-
 gatchat/ppp_cp.c   |    6 ++----
 gatchat/ppp_net.c  |    3 ++-
 5 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/gatchat/gatppp.c b/gatchat/gatppp.c
index 70669b0..c4f59f2 100644
--- a/gatchat/gatppp.c
+++ b/gatchat/gatppp.c
@@ -148,7 +148,8 @@ static void ppp_receive(const unsigned char *buf, gsize len, void *data)
  */
 void ppp_transmit(GAtPPP *ppp, guint8 *packet, guint infolen)
 {
-	guint16 proto = get_host_short(packet);
+	struct ppp_header *header = (struct ppp_header *) packet;
+	guint16 proto = ppp_proto(packet);
 	guint8 code;
 	gboolean lcp = (proto == LCP_PROTOCOL);
 	guint32 xmit_accm = 0;
@@ -167,7 +168,11 @@ void ppp_transmit(GAtPPP *ppp, guint8 *packet, guint infolen)
 		g_at_hdlc_set_xmit_accm(ppp->hdlc, ~0U);
 	}
 
-	if (g_at_hdlc_send(ppp->hdlc, packet, infolen + 2) == FALSE)
+	header->address = PPP_ADDR_FIELD;
+	header->control = PPP_CTRL;
+
+	if (g_at_hdlc_send(ppp->hdlc, packet,
+			infolen + sizeof(*header)) == FALSE)
 		g_print("Failed to send a frame\n");
 
 	if (lcp)
diff --git a/gatchat/ppp.h b/gatchat/ppp.h
index 41cf50a..e872496 100644
--- a/gatchat/ppp.h
+++ b/gatchat/ppp.h
@@ -26,11 +26,15 @@
 #define IPCP_PROTO	0x8021
 #define PPP_IP_PROTO	0x0021
 #define MD5		5
+#define PPP_ADDR_FIELD	0xff
+#define PPP_CTRL	0x03
 
 struct ppp_chap;
 struct ppp_net;
 
 struct ppp_header {
+	guint8 address;
+	guint8 control;
 	guint16 proto;
 	guint8 info[0];
 } __attribute__((packed));
diff --git a/gatchat/ppp_auth.c b/gatchat/ppp_auth.c
index 6e55297..eae5d17 100644
--- a/gatchat/ppp_auth.c
+++ b/gatchat/ppp_auth.c
@@ -83,7 +83,7 @@ static void chap_process_challenge(struct ppp_chap *chap, const guint8 *packet)
 	 */
 	digest_len = g_checksum_type_get_length(chap->method);
 	response_length = digest_len + sizeof(*header) + 1;
-	ppp_packet = g_try_malloc0(response_length + 2);
+	ppp_packet = g_try_malloc0(response_length + sizeof(struct ppp_header));
 	if (!ppp_packet)
 		goto challenge_out;
 
diff --git a/gatchat/ppp_cp.c b/gatchat/ppp_cp.c
index 00acb73..e152f6e 100644
--- a/gatchat/ppp_cp.c
+++ b/gatchat/ppp_cp.c
@@ -61,10 +61,8 @@ static const char *pppcp_event_strings[] = {
 	g_free(str); \
 } while (0);
 
-#define PPP_HEADROOM	2
-
 #define pppcp_to_ppp_packet(p) \
-	(((guint8 *) p) - PPP_HEADROOM)
+	(((guint8 *) p) - sizeof(struct ppp_header))
 
 #define INITIAL_RESTART_TIMEOUT	3	/* restart interval in seconds */
 #define MAX_TERMINATE		2
@@ -206,7 +204,7 @@ static struct pppcp_packet *pppcp_packet_new(struct pppcp_data *data,
 	struct ppp_header *ppp_packet;
 	guint16 packet_length = bufferlen + sizeof(*packet);
 
-	ppp_packet = g_try_malloc0(packet_length + 2);
+	ppp_packet = g_try_malloc0(packet_length + sizeof(*ppp_packet));
 	if (!ppp_packet)
 		return NULL;
 
diff --git a/gatchat/ppp_net.c b/gatchat/ppp_net.c
index afebf58..4e45ef1 100644
--- a/gatchat/ppp_net.c
+++ b/gatchat/ppp_net.c
@@ -105,7 +105,8 @@ static gboolean ppp_net_callback(GIOChannel *channel, GIOCondition cond,
 
 	if (cond & G_IO_IN) {
 		/* leave space to add PPP protocol field */
-		status = g_io_channel_read_chars(channel, buf + 2, net->mtu,
+		status = g_io_channel_read_chars(channel,
+				buf + sizeof(struct ppp_header), net->mtu,
 				&bytes_read, &error);
 		if (bytes_read > 0) {
 			ppp->proto = htons(PPP_IP_PROTO);
-- 
1.6.6.1

Re: [PATCH] ppp: set address and control field

[Denis Kenzior]

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Hi Kristen,

> Before sending to hdlc, set the address and control field.
> Fix hardcode of ppp header size.

Patch has been applied with one minor modification:

> +#define PPP_ADDR_FIELD	0xff
> +#define PPP_CTRL	0x03

These really should be private.

> @@ -83,7 +83,7 @@ static void chap_process_challenge(struct ppp_chap *chap,
>  const guint8 *packet) */
>  	digest_len = g_checksum_type_get_length(chap->method);
>  	response_length = digest_len + sizeof(*header) + 1;
> -	ppp_packet = g_try_malloc0(response_length + 2);
> +	ppp_packet = g_try_malloc0(response_length + sizeof(struct ppp_header));
>  	if (!ppp_packet)
>  		goto challenge_out;

Can we make this function use pppcp_packet_new or similar?

Regards,
-Denis