Re: [PATCH v2] ax25-tools: mheard

[walter harms <wharms@bfs.de>]

Am 17.07.2016 22:14, schrieb Guido Trentalancia:
> The following patch prevents fatal segmentation faults errors
> on strcpy() in the mheard tool when the result of ctime() is
> zero and it also avoids printing inconsistent log entries.
> 
> This second version includes revisions from Thomas Osterried
> and it is correctly based on code from the current git tree.
> 
> Signed-off-by: Guido Trentalancia <iz6rdb@trentalancia.net>
> ---
>  ax25/mheard.c |   62 ++++++++++++++++++++++++++++++++++++++++------------------
>  1 file changed, 43 insertions(+), 19 deletions(-)
> 
> --- ax25-tools-git-17072016-2126/ax25/mheard.c	2016-07-17 21:25:22.547557162 +0200
> +++ ax25-tools-git-17072016-2126-fix-mheard/ax25/mheard.c	2016-07-17 22:05:19.925283229 +0200
> @@ -60,19 +60,25 @@ static void PrintHeader(int data)
>  
>  static void PrintPortEntry(struct PortRecord *pr, int data)
>  {
> -	char lh[30], fh[30], *call, *s;
> +	char lh[33], fh[33], *call, *s, *ctime_out;
>  	char buffer[80];
> -	int i;
> +	int i, pkt_count;
>  
>  	switch (data) {
>  	case 0:
> -		strcpy(lh, ctime(&pr->entry.last_heard));
> -		lh[19] = 0;
> +		ctime_out = ctime(&pr->entry.last_heard);
> +		if (!ctime_out)
> +			break;
> +		strcpy(lh, ctime_out);
> +		lh[32] = 0;
>  		call =  ax25_ntoa(&pr->entry.from_call);
>  		if ((s = strstr(call, "-0")) != NULL)
>  			*s = '\0';
> -		printf("%-9s  %-5s  %5d   %s\n",
> -			call, pr->entry.portname, pr->entry.count, lh);
> +		pkt_count = pr->entry.count;
> +		if (!pkt_count)
> +			break;
> +		printf("%-9s  %-5s  %5u   %s\n",
> +			call, pr->entry.portname, pkt_count, lh);
>  		break;

my i asc why you use strcpy/ctime in the first place ?
you can use strftime:

	tm=mktime(&pr->entry.last_heard);
	if (!tm)
	   break;
	strftime(lh, sizeof(lh),"%Y-%m-%d %H:%M:%S",tm);


just my two cents,

re,
 wh

>  	case 1:
>  		buffer[0] = '\0';
> @@ -98,22 +104,31 @@ static void PrintPortEntry(struct PortRe
>  			buffer, pr->entry.portname);
>  		break;
>  	case 2:
> -		strcpy(lh, ctime(&pr->entry.last_heard));
> -		lh[19] = 0;
> -		strcpy(fh, ctime(&pr->entry.first_heard));
> -		fh[19] = 0;
> +		ctime_out = ctime(&pr->entry.last_heard);
> +		if (!ctime_out)
> +			break;
> +		strcpy(lh, ctime_out);
> +		lh[32] = 0;
> +		ctime_out = ctime(&pr->entry.first_heard);
> +		if (!ctime_out)
> +			break;
> +		strcpy(fh, ctime_out);
> +		fh[32] = 0;
>  		call = ax25_ntoa(&pr->entry.from_call);
>  		if ((s = strstr(call, "-0")) != NULL)
>  			*s = '\0';
> -		printf("%-9s  %-5s  %5d %5d %5d  %s  %s\n",
> +		printf("%-9s  %-5s  %5u %5u %5u  %s  %s\n",
>  			call, pr->entry.portname, pr->entry.iframes, pr->entry.sframes, pr->entry.uframes, fh, lh);
>  		break;
>  	case 3:
>  		call = ax25_ntoa(&pr->entry.from_call);
>  		if ((s = strstr(call, "-0")) != NULL)
>  			*s = '\0';
> -		printf("%-9s  %-5s  %5d %5s ",
> -			call, pr->entry.portname, pr->entry.count, types[pr->entry.type]);
> +		pkt_count = pr->entry.count;
> +		if (!pkt_count)
> +			break;	
> +		printf("%-9s  %-5s  %5u %5s ",
> +			call, pr->entry.portname, pkt_count, types[pr->entry.type]);
>  		if (pr->entry.mode & MHEARD_MODE_ARP)
>  			printf(" ARP");
>  		if (pr->entry.mode & MHEARD_MODE_FLEXNET)
> @@ -141,16 +156,25 @@ static void PrintPortEntry(struct PortRe
>  		printf("\n");
>  		break;
>  	case 4:
> -		strcpy(lh, ctime(&pr->entry.last_heard));
> -		lh[19] = 0;
> -		strcpy(fh, ctime(&pr->entry.first_heard));
> -		fh[19] = 0;
> +		ctime_out = ctime(&pr->entry.last_heard);
> +		if (!ctime_out)
> +			break;
> +		strcpy(lh, ctime_out);
> +		lh[32] = 0;
> +		ctime_out = ctime(&pr->entry.first_heard);
> +		if (!ctime_out)
> +			break;
> +		strcpy(fh, ctime_out);
> +		fh[32] = 0;
>  		call = ax25_ntoa(&pr->entry.from_call);
>  		if ((s = strstr(call, "-0")) != NULL)
>  			*s = '\0';
> -		printf("%-9s  %-5s  %5d %5d %5d  %s  %s",
> +		pkt_count = pr->entry.count;
> +		if (!pkt_count)
> +			break;
> +		printf("%-9s  %-5s  %5u %5u %5u  %s  %s",
>  			call, pr->entry.portname, pr->entry.iframes, pr->entry.sframes, pr->entry.uframes, fh, lh);
> -		printf("%5d    %5s ", pr->entry.count, types[pr->entry.type]);
> +		printf("%5d    %5s ", pkt_count, types[pr->entry.type]);
>  		if (pr->entry.mode & MHEARD_MODE_ARP)
>  			printf(" ARP      ");
>  		if (pr->entry.mode & MHEARD_MODE_FLEXNET)
> --
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