[SLOF] [PATCH v3 2/3] ping: add netmask in the ping argument

Thomas Huth thuth at redhat.com
Tue May 3 17:43:19 AEST 2016


On 03.05.2016 06:01, Nikunj A Dadhania wrote:
> The current ping command does not take netmask as argument, updated the
> ping command to take "client-ip/nn" format ip address.
> 
> Add routine to return netmask(class based), when not provided by user.
> 
> Signed-off-by: Nikunj A Dadhania <nikunj at linux.vnet.ibm.com>
> ---
>  clients/net-snk/app/netapps/args.c | 44 ++++++++++++++++++++++++++++++++++----
>  clients/net-snk/app/netapps/args.h |  1 +
>  clients/net-snk/app/netapps/ping.c | 21 ++++++++++++++++--
>  clients/net-snk/app/netlib/ipv4.c  | 21 ++++++++++++++++++
>  clients/net-snk/app/netlib/ipv4.h  |  1 +
>  slof/fs/loaders.fs                 |  4 ++--
>  6 files changed, 84 insertions(+), 8 deletions(-)
> 
> diff --git a/clients/net-snk/app/netapps/args.c b/clients/net-snk/app/netapps/args.c
> index 52215e6..ed25c7c 100644
> --- a/clients/net-snk/app/netapps/args.c
> +++ b/clients/net-snk/app/netapps/args.c
> @@ -98,20 +98,22 @@ argncpy(const char *arg_str, unsigned int index, char *buffer,
>  }
>  
>  /**
> - * Converts "255.255.255.255" -> char[4] = { 0xff, 0xff, 0xff, 0xff }
> + * Converts "255.255.255.255/nn" -> char[4] = { 0xff, 0xff, 0xff, 0xff }
> + *                                  *netmask = subnet_netmask(nn)
>   *
>   * @param  str        string to be converted
>   * @param  ip         in case of SUCCESS - 32-bit long IP
> -                      in case of FAULT - zero
> + *                    in case of FAULT - zero
> + * @param  netmask    return netmask if there is a valid /nn encoding in IP
>   * @return            TRUE - IP converted successfully;
>   *                    FALSE - error condition occurs (e.g. bad format)
>   */
>  int
> -strtoip(const char *str, char ip[4])
> +strtoip_netmask(const char *str, char ip[4], unsigned int *netmask)
>  {
>  	char octet[10];
>  	int res;
> -	unsigned int i = 0, len;
> +	unsigned int i = 0, len, has_nn = 0;
>  
>  	while (*str != 0) {
>  		if (i > 3 || !isdigit(*str))
> @@ -123,6 +125,14 @@ strtoip(const char *str, char ip[4])
>  			strncpy(octet, str, len);
>  			octet[len] = 0;
>  			str += len;
> +		} else if (strstr(str, "\\") != NULL) {
> +			len = (short) (strstr(str, "\\") - str);

Shouldn't that be a forward slash instead? Or will this cause trouble
with the slash handling from the Forth code? (in the latter case, you
should at least adapt the 'Converts "255.255.255.255/nn"' comment in
front of this function, I think)

Anyway, you could also use strchr() instead of strstr() as a small
optimization, I think.

> +			if (len >= 10)
> +				return 0;
> +			strncpy(octet, str, len);
> +			octet[len] = 0;
> +			str += len;
> +			has_nn = 1;
>  		} else {
>  			strncpy(octet, str, 9);
>  			octet[9] = 0;
> @@ -135,9 +145,35 @@ strtoip(const char *str, char ip[4])
>  		i++;
>  		if (*str == '.')
>  			str++;
> +		if(has_nn) {
> +			str++;
> +			strncpy(octet, str, 9);
> +			octet[9] = 0;
> +			res = strtol(octet, NULL, 10);
> +			str += strlen(octet);
> +			if (res > 31 || res < 1)
> +				return 0;
> +			if (netmask)
> +				*netmask = (0xFFFFFFFFUL << (32 - res)) & 0xFFFFFFFFUL;

I think you could simply do without the final "& 0xFFFFFFFFUL" here.
And for the first 0xFFFFFFFF, you also don't need the UL suffix, do you?

> +		}
>  	}
>  
>  	if (i != 4)
>  		return 0;
>  	return -1;
>  }
> +
> +/**
> + * Converts "255.255.255.255" -> char[4] = { 0xff, 0xff, 0xff, 0xff }
> + *
> + * @param  str        string to be converted
> + * @param  ip         in case of SUCCESS - 32-bit long IP
> + in case of FAULT - zero
> + * @return            TRUE - IP converted successfully;
> + *                    FALSE - error condition occurs (e.g. bad format)
> + */
> +int
> +strtoip(const char *str, char ip[4])
> +{
> +	return strtoip_netmask(str, ip, NULL);
> +}
> diff --git a/clients/net-snk/app/netapps/args.h b/clients/net-snk/app/netapps/args.h
> index b80982a..1ede9a8 100644
> --- a/clients/net-snk/app/netapps/args.h
> +++ b/clients/net-snk/app/netapps/args.h
> @@ -18,5 +18,6 @@ unsigned int get_args_count(const char *);
>  unsigned int get_arg_length(const char *);
>  char *argncpy(const char *, unsigned int, char *, unsigned int);
>  int strtoip(const char *, char[4]);
> +int strtoip_netmask(const char *, char[4], unsigned int *netmask);
>  
>  #endif				/* _ARGS_H */
> diff --git a/clients/net-snk/app/netapps/ping.c b/clients/net-snk/app/netapps/ping.c
> index 4facf06..bd8f2d3 100644
> --- a/clients/net-snk/app/netapps/ping.c
> +++ b/clients/net-snk/app/netapps/ping.c
> @@ -35,13 +35,15 @@ struct ping_args {
>  		unsigned int integer;
>  	} gateway_ip;
>  	unsigned int timeout;
> +	/* Netmask 192.168.1.10/24 format */

What do you mean with "192.168.1.10/24 format" here? You store here the
real netmask, not the prefix length, right?

> +	unsigned int netmask;
>  };
>  
>  static void
>  usage(void)
>  {
>  	printf
> -	    ("\nping device-path:[device-args,]server-ip,[client-ip],[gateway-ip][,timeout]\n");
> +	    ("\nping device-path:[device-args,]server-ip,[client-ip[\\nn]],[gateway-ip][,timeout]\n");
>  }
>  
> @@ -82,7 +84,7 @@ parse_args(const char *args, struct ping_args *ping_args)
>  	}
>  
>  	argncpy(args, 0, buf, 64);
> -	if (!strtoip(buf, ping_args->client_ip.string)) {
> +	if (!strtoip_netmask(buf, ping_args->client_ip.string, &ping_args->netmask)) {
>  		/* this should have been the client (our) IP address */
>  		return -1;
>  	} else {
> @@ -112,6 +114,7 @@ ping(int argc, char *argv[])
>  	int fd_device;
>  	struct ping_args ping_args;
>  	uint8_t own_mac[6];
> +	uint32_t netmask;
>  
>  	memset(&ping_args, 0, sizeof(struct ping_args));
>  
> @@ -163,6 +166,14 @@ ping(int argc, char *argv[])
>  
>  	} else {
>  		memcpy(&fn_ip.own_ip, &ping_args.client_ip.integer, 4);
> +		if (!ping_args.netmask) {
> +			/* Netmask is not provided, assume default according to
> +			 * the network class
> +			 */
> +			ping_args.netmask = get_default_ipv4_netmask(ping_args.client_ip.string);
> +		}
> +		set_ipv4_netmask(ping_args.netmask);
> +
>  		arp_failed = 1;
>  		printf("  Own IP address: ");
>  	}
> @@ -174,6 +185,12 @@ ping(int argc, char *argv[])
>  	       ((fn_ip.own_ip >> 24) & 0xFF), ((fn_ip.own_ip >> 16) & 0xFF),
>  	       ((fn_ip.own_ip >> 8) & 0xFF), (fn_ip.own_ip & 0xFF));
>  
> +	if ((netmask = get_ipv4_netmask())) {

Just a matter of taste - but could you maybe write that in two lines:

	netmask = get_ipv4_netmask();
	if (netmask) ...

> +		printf("  Netmask : ");
> +		printf("%d.%d.%d.%d\n", ((netmask >> 24) & 0xFF), ((netmask >> 16) & 0xFF),
> +		       ((netmask >> 8) & 0xFF), (netmask & 0xFF));
> +	}
> +
>  	memcpy(&fn_ip.server_ip, &ping_args.server_ip.integer, 4);
>  	printf("  Ping to %d.%d.%d.%d ", ((fn_ip.server_ip >> 24) & 0xFF),
>  	       ((fn_ip.server_ip >> 16) & 0xFF),
> diff --git a/clients/net-snk/app/netlib/ipv4.c b/clients/net-snk/app/netlib/ipv4.c
> index 2b92c77..3a1a789 100644
> --- a/clients/net-snk/app/netlib/ipv4.c
> +++ b/clients/net-snk/app/netlib/ipv4.c
> @@ -250,6 +250,27 @@ uint32_t get_ipv4_netmask(void)
>  }
>  
>  /**
> + * IPv4: Get the default subnet mask according to the IP class
> + *
> + * @param ip_addr IPv4 address
> + * @return default netmask according to the IP class
> + */
> +uint32_t get_default_ipv4_netmask(char *ip_addr)
> +{
> +	unsigned char top;
> +
> +	top = ip_addr[0];
> +	if (top > 0 && top < 128)
> +		return 0xFF000000; /* Class A: 255.0.0.0 */
> +	else if (top >= 128 && top < 192)
> +		return 0xFFFF0000; /* Class B: 255.255.0.0 */
> +	else if (top >= 192 && top < 224)
> +		return 0xFFFFFF00; /* Class C: 255.255.255.0 */
> +	else
> +		return 0;
> +}
> +
> +/**
>   * IPv4: Creates IP-packet. Places IP-header in a packet and fills it
>   *       with corresponding information.
>   *       <p>
> diff --git a/clients/net-snk/app/netlib/ipv4.h b/clients/net-snk/app/netlib/ipv4.h
> index 18821ea..5717c9a 100644
> --- a/clients/net-snk/app/netlib/ipv4.h
> +++ b/clients/net-snk/app/netlib/ipv4.h
> @@ -69,6 +69,7 @@ extern void     set_ipv4_router(uint32_t router_ip);
>  extern uint32_t get_ipv4_router(void);
>  extern void     set_ipv4_netmask(uint32_t subnet_mask);
>  extern uint32_t get_ipv4_netmask(void);
> +extern uint32_t get_default_ipv4_netmask(char *ip_addr);
>  
>  extern int   (*send_ip) (int fd, void *, int);
>  
> diff --git a/slof/fs/loaders.fs b/slof/fs/loaders.fs
> index 1478c70..8ae502d 100644
> --- a/slof/fs/loaders.fs
> +++ b/slof/fs/loaders.fs
> @@ -70,7 +70,7 @@ CREATE load-list 2 cells allot load-list 2 cells erase
>     THEN
>  ;
>  
> -: ping  ( "{device-path:[device-args,]server-ip,[client-ip],[gateway-ip][,timeout]}" -- )
> +: ping  ( "{device-path:[device-args,]server-ip,[client-ip[\nn]],[gateway-ip][,timeout]}" -- )
>     my-self >r current-node @ >r  \ Save my-self
>     (parse-line) open-dev dup  IF
>        dup to my-self dup ihandle>phandle set-node
> @@ -83,7 +83,7 @@ CREATE load-list 2 cells allot load-list 2 cells erase
>        swap close-dev
>     ELSE
>        cr
> -      ." Usage: ping device-path:[device-args,]server-ip,[client-ip],[gateway-ip][,timeout]"
> +      ." Usage: ping device-path:[device-args,]server-ip,[client-ip[\nn]],[gateway-ip][,timeout]"
>        cr drop
>     THEN
>     r> set-node r> to my-self  \ Restore my-self
> 

Apart from the nits, the patch looks fine to me.

 Thomas



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