| Message ID | 1310893024-21615-6-git-send-email-asias.hejun@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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; > +}
On 07/17/2011 05:36 PM, Sasha Levin wrote: > 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 Yup. We need to check the return value of 'fscanf'. My gcc (4.6.1) does not catch this by default, I guess we need to enable this explicitly in our Makefile. >> 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; >> +} > >
On Mon, 2011-07-18 at 12:48 +0800, Asias He wrote: > My gcc (4.6.1) does not catch this by default, I guess we need to enable > this explicitly in our Makefile. Yes, please. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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; +}
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> --- tools/kvm/include/kvm/uip.h | 6 ++++++ tools/kvm/net/uip/dhcp.c | 34 ++++++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+), 0 deletions(-)