Re: [PATCH 05/16] kvm tools: Get domain name and nameserver from host

[Sasha Levin <levinsasha928@gmail.com>]

On Sun, 2011-07-17 at 16:56 +0800, Asias He wrote:
> This patch get domain name and nameserver information from host config
> file /etc/resolv.conf.
> 
> Guest can obtain DNS information through DHCP.
> 
> Signed-off-by: Asias He <asias.hejun@gmail.com>
> ---

Seeing this after this patch:

cc1: warnings being treated as errors
net/uip/dhcp.c: In function 'uip_dhcp_get_dns':
net/uip/dhcp.c:49:9: error: ignoring return value of 'fscanf', declared
with attribute warn_unused_result
make: *** [net/uip/dhcp.o] Error 1

>  tools/kvm/include/kvm/uip.h |    6 ++++++
>  tools/kvm/net/uip/dhcp.c    |   34 ++++++++++++++++++++++++++++++++++
>  2 files changed, 40 insertions(+), 0 deletions(-)
> 
> diff --git a/tools/kvm/include/kvm/uip.h b/tools/kvm/include/kvm/uip.h
> index 6534c7f..e645d3f 100644
> --- a/tools/kvm/include/kvm/uip.h
> +++ b/tools/kvm/include/kvm/uip.h
> @@ -42,6 +42,8 @@
>  #define UIP_DHCP_OFFER			2
>  #define UIP_DHCP_REQUEST		3
>  #define UIP_DHCP_ACK			5
> +#define UIP_DHCP_MAX_DNS_SERVER_NR	3
> +#define UIP_DHCP_MAX_DOMAIN_NAME_LEN	256
>  #define UIP_DHCP_TAG_MSG_TYPE		53
>  #define UIP_DHCP_TAG_MSG_TYPE_LEN	1
>  /*
> @@ -178,6 +180,8 @@ struct uip_info {
>  	int buf_free_nr;
>  	int buf_used_nr;
>  	u32 host_ip;
> +	u32 dns_ip[UIP_DHCP_MAX_DNS_SERVER_NR];
> +	char *domain_name;
>  	u32 buf_nr;
>  };
>  
> @@ -327,4 +331,6 @@ struct uip_buf *uip_buf_clone(struct uip_tx_arg *arg);
>  
>  int uip_udp_make_pkg(struct uip_info *info, struct uip_udp_socket *sk, struct uip_buf *buf, u8 *payload, int payload_len);
>  bool uip_udp_is_dhcp(struct uip_udp *udp);
> +
> +int uip_dhcp_get_dns(struct uip_info *info);
>  #endif /* KVM__UIP_H */
> diff --git a/tools/kvm/net/uip/dhcp.c b/tools/kvm/net/uip/dhcp.c
> index 0a6293a..9321cdc 100644
> --- a/tools/kvm/net/uip/dhcp.c
> +++ b/tools/kvm/net/uip/dhcp.c
> @@ -1,5 +1,7 @@
>  #include "kvm/uip.h"
>  
> +#include <arpa/inet.h>
> +
>  static inline bool uip_dhcp_is_discovery(struct uip_dhcp *dhcp)
>  {
>  	return (dhcp->option[2] == UIP_DHCP_DISCOVER &&
> @@ -29,3 +31,35 @@ bool uip_udp_is_dhcp(struct uip_udp *udp)
>  
>  	return true;
>  }
> +
> +int uip_dhcp_get_dns(struct uip_info *info)
> +{
> +	char key[256], val[256];
> +	struct in_addr addr;
> +	int ret = -1;
> +	int n = 0;
> +	FILE *fp;
> +	u32 ip;
> +
> +	fp = fopen("/etc/resolv.conf", "r");
> +	if (!fp)
> +		goto out;
> +
> +	while (!feof(fp)) {
> +		fscanf(fp, "%s %s\n", key, val);
> +		if (strncmp("domain", key, 6) == 0)
> +			info->domain_name = strndup(val, UIP_DHCP_MAX_DOMAIN_NAME_LEN);
> +		else if (strncmp("nameserver", key, 10) == 0) {
> +			if (!inet_aton(val, &addr))
> +				continue;
> +			ip = ntohl(addr.s_addr);
> +			if (n < UIP_DHCP_MAX_DNS_SERVER_NR)
> +				info->dns_ip[n++] = ip;
> +			ret = 0;
> +		}
> +	}
> +
> +out:
> +	fclose(fp);
> +	return ret;
> +}


-- 

Sasha.