Subject: Re: [PATCH next] netfilter: nf_conntrack_h323: Correct indentation when H323_TRACE defined

From: Pablo Neira Ayuso <[email-masked]>
Date: Thu, 26 Mar 2026 21:24:39 +0100

Hi David,

On Thu, Mar 26, 2026 at 08:18:19PM +0000, [email-masked] wrote:
> From: David Laight <[email-masked]>
> 
> The trace lines are indented using PRINT("%*.s", xx, " ").
> Userspace will treat this as "%*.0s" and will output no characters
> when 'xx' is zero, the kernel treats it as "%*s" and will output
> a single ' ' - which is probably what is intended.
> 
> Change all the formats to "%*s" removing the default precision.
> This gives a single space indent when level is zero.

Do you have a setup using this helper? Or you just found this via
visual inspection?

> Signed-off-by: David Laight <[email-masked]>
> ---
>  net/netfilter/nf_conntrack_h323_asn1.c | 38 +++++++++++++-------------
>  1 file changed, 19 insertions(+), 19 deletions(-)
> 
> diff --git a/net/netfilter/nf_conntrack_h323_asn1.c b/net/netfilter/nf_conntrack_h323_asn1.c
> index 7b1497ed97d2..287402428975 100644
> --- a/net/netfilter/nf_conntrack_h323_asn1.c
> +++ b/net/netfilter/nf_conntrack_h323_asn1.c
> @@ -276,7 +276,7 @@ static unsigned int get_uint(struct bitstr *bs, int b)
>  static int decode_nul(struct bitstr *bs, const struct field_t *f,
>                        char *base, int level)
>  {
> -	PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name);
> +	PRINT("%*s%s\n", level * TAB_SIZE, " ", f->name);
>  
>  	return H323_ERROR_NONE;
>  }
> @@ -284,7 +284,7 @@ static int decode_nul(struct bitstr *bs, const struct field_t *f,
>  static int decode_bool(struct bitstr *bs, const struct field_t *f,
>                         char *base, int level)
>  {
> -	PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name);
> +	PRINT("%*s%s\n", level * TAB_SIZE, " ", f->name);
>  
>  	INC_BIT(bs);
>  	if (nf_h323_error_boundary(bs, 0, 0))
> @@ -297,7 +297,7 @@ static int decode_oid(struct bitstr *bs, const struct field_t *f,
>  {
>  	int len;
>  
> -	PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name);
> +	PRINT("%*s%s\n", level * TAB_SIZE, " ", f->name);
>  
>  	BYTE_ALIGN(bs);
>  	if (nf_h323_error_boundary(bs, 1, 0))
> @@ -316,7 +316,7 @@ static int decode_int(struct bitstr *bs, const struct field_t *f,
>  {
>  	unsigned int len;
>  
> -	PRINT("%*.s%s", level * TAB_SIZE, " ", f->name);
> +	PRINT("%*s%s", level * TAB_SIZE, " ", f->name);
>  
>  	switch (f->sz) {
>  	case BYTE:		/* Range == 256 */
> @@ -363,7 +363,7 @@ static int decode_int(struct bitstr *bs, const struct field_t *f,
>  static int decode_enum(struct bitstr *bs, const struct field_t *f,
>                         char *base, int level)
>  {
> -	PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name);
> +	PRINT("%*s%s\n", level * TAB_SIZE, " ", f->name);
>  
>  	if ((f->attr & EXT) && get_bit(bs)) {
>  		INC_BITS(bs, 7);
> @@ -381,7 +381,7 @@ static int decode_bitstr(struct bitstr *bs, const struct field_t *f,
>  {
>  	unsigned int len;
>  
> -	PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name);
> +	PRINT("%*s%s\n", level * TAB_SIZE, " ", f->name);
>  
>  	BYTE_ALIGN(bs);
>  	switch (f->sz) {
> @@ -417,7 +417,7 @@ static int decode_numstr(struct bitstr *bs, const struct field_t *f,
>  {
>  	unsigned int len;
>  
> -	PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name);
> +	PRINT("%*s%s\n", level * TAB_SIZE, " ", f->name);
>  
>  	/* 2 <= Range <= 255 */
>  	if (nf_h323_error_boundary(bs, 0, f->sz))
> @@ -437,7 +437,7 @@ static int decode_octstr(struct bitstr *bs, const struct field_t *f,
>  {
>  	unsigned int len;
>  
> -	PRINT("%*.s%s", level * TAB_SIZE, " ", f->name);
> +	PRINT("%*s%s", level * TAB_SIZE, " ", f->name);
>  
>  	switch (f->sz) {
>  	case FIXD:		/* Range == 1 */
> @@ -490,7 +490,7 @@ static int decode_bmpstr(struct bitstr *bs, const struct field_t *f,
>  {
>  	unsigned int len;
>  
> -	PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name);
> +	PRINT("%*s%s\n", level * TAB_SIZE, " ", f->name);
>  
>  	switch (f->sz) {
>  	case BYTE:		/* Range == 256 */
> @@ -522,7 +522,7 @@ static int decode_seq(struct bitstr *bs, const struct field_t *f,
>  	const struct field_t *son;
>  	unsigned char *beg = NULL;
>  
> -	PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name);
> +	PRINT("%*s%s\n", level * TAB_SIZE, " ", f->name);
>  
>  	/* Decode? */
>  	base = (base && (f->attr & DECODE)) ? base + f->offset : NULL;
> @@ -544,7 +544,7 @@ static int decode_seq(struct bitstr *bs, const struct field_t *f,
>  	/* Decode the root components */
>  	for (i = opt = 0, son = f->fields; i < f->lb; i++, son++) {
>  		if (son->attr & STOP) {
> -			PRINT("%*.s%s\n", (level + 1) * TAB_SIZE, " ",
> +			PRINT("%*s%s\n", (level + 1) * TAB_SIZE, " ",
>  			      son->name);
>  			return H323_ERROR_STOP;
>  		}
> @@ -562,7 +562,7 @@ static int decode_seq(struct bitstr *bs, const struct field_t *f,
>  			if (nf_h323_error_boundary(bs, len, 0))
>  				return H323_ERROR_BOUND;
>  			if (!base || !(son->attr & DECODE)) {
> -				PRINT("%*.s%s\n", (level + 1) * TAB_SIZE,
> +				PRINT("%*s%s\n", (level + 1) * TAB_SIZE,
>  				      " ", son->name);
>  				bs->cur += len;
>  				continue;
> @@ -615,7 +615,7 @@ static int decode_seq(struct bitstr *bs, const struct field_t *f,
>  		}
>  
>  		if (son->attr & STOP) {
> -			PRINT("%*.s%s\n", (level + 1) * TAB_SIZE, " ",
> +			PRINT("%*s%s\n", (level + 1) * TAB_SIZE, " ",
>  			      son->name);
>  			return H323_ERROR_STOP;
>  		}
> @@ -629,7 +629,7 @@ static int decode_seq(struct bitstr *bs, const struct field_t *f,
>  		if (nf_h323_error_boundary(bs, len, 0))
>  			return H323_ERROR_BOUND;
>  		if (!base || !(son->attr & DECODE)) {
> -			PRINT("%*.s%s\n", (level + 1) * TAB_SIZE, " ",
> +			PRINT("%*s%s\n", (level + 1) * TAB_SIZE, " ",
>  			      son->name);
>  			bs->cur += len;
>  			continue;
> @@ -655,7 +655,7 @@ static int decode_seqof(struct bitstr *bs, const struct field_t *f,
>  	const struct field_t *son;
>  	unsigned char *beg = NULL;
>  
> -	PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name);
> +	PRINT("%*s%s\n", level * TAB_SIZE, " ", f->name);
>  
>  	/* Decode? */
>  	base = (base && (f->attr & DECODE)) ? base + f->offset : NULL;
> @@ -710,7 +710,7 @@ static int decode_seqof(struct bitstr *bs, const struct field_t *f,
>  			if (nf_h323_error_boundary(bs, len, 0))
>  				return H323_ERROR_BOUND;
>  			if (!base || !(son->attr & DECODE)) {
> -				PRINT("%*.s%s\n", (level + 1) * TAB_SIZE,
> +				PRINT("%*s%s\n", (level + 1) * TAB_SIZE,
>  				      " ", son->name);
>  				bs->cur += len;
>  				continue;
> @@ -751,7 +751,7 @@ static int decode_choice(struct bitstr *bs, const struct field_t *f,
>  	const struct field_t *son;
>  	unsigned char *beg = NULL;
>  
> -	PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name);
> +	PRINT("%*s%s\n", level * TAB_SIZE, " ", f->name);
>  
>  	/* Decode? */
>  	base = (base && (f->attr & DECODE)) ? base + f->offset : NULL;
> @@ -792,7 +792,7 @@ static int decode_choice(struct bitstr *bs, const struct field_t *f,
>  	/* Transfer to son level */
>  	son = &f->fields[type];
>  	if (son->attr & STOP) {
> -		PRINT("%*.s%s\n", (level + 1) * TAB_SIZE, " ", son->name);
> +		PRINT("%*s%s\n", (level + 1) * TAB_SIZE, " ", son->name);
>  		return H323_ERROR_STOP;
>  	}
>  
> @@ -804,7 +804,7 @@ static int decode_choice(struct bitstr *bs, const struct field_t *f,
>  		if (nf_h323_error_boundary(bs, len, 0))
>  			return H323_ERROR_BOUND;
>  		if (!base || !(son->attr & DECODE)) {
> -			PRINT("%*.s%s\n", (level + 1) * TAB_SIZE, " ",
> +			PRINT("%*s%s\n", (level + 1) * TAB_SIZE, " ",
>  			      son->name);
>  			bs->cur += len;
>  			return H323_ERROR_NONE;
> -- 
> 2.39.5
>