Hi Naveen,
On to, 2015-10-01 at 23:00 -0700, Naveen Singh wrote:
> On Thu, Oct 1, 2015 at 6:26 AM, Patrik Flykt <[email protected]>
> wrote:
>
> >
> > Hi,
> >
> > On Wed, 2015-09-30 at 22:08 -0700, Naveen Singh wrote:
> > > From: Naveen Singh <[email protected]>
> > >
> > > Current NTP code is written with an assumption that timeserver is
> > > always an IPv4 address. If there is an IPv6 timeserver then the socket
> > > operation would fail with error as Permission denied (13). This change in
> > > ntp.c ensures that code works fine with both IPv4 and IPv6 address.
> > > ---
> > > src/ntp.c | 129
> > ++++++++++++++++++++++++++++++++++++++++++++++++--------------
> > > 1 file changed, 101 insertions(+), 28 deletions(-)
> >
> > This was patch version 2, so the next one is version 3. Add the version
> > to the Subject: line as [PATCH v3], this can be done with
> > 'git ... --subject-prefix="PATCH v3" ...'.
> >
> > > diff --git a/src/ntp.c b/src/ntp.c
> > > index 2c313a4..a55365d 100644
> > > --- a/src/ntp.c
> > > +++ b/src/ntp.c
> > > @@ -18,7 +18,6 @@
> > > * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
> > 02110-1301 USA
> > > *
> > > */
> > > -
> > > #ifdef HAVE_CONFIG_H
> > > #include <config.h>
> > > #endif
> > > @@ -34,6 +33,7 @@
> > > #include <netinet/in.h>
> > > #include <netinet/ip.h>
> > > #include <arpa/inet.h>
> > > +#include <netdb.h>
> > >
> > > #include <glib.h>
> > >
> > > @@ -117,12 +117,12 @@ static struct timespec mtx_time;
> > > static int transmit_fd = 0;
> > >
> > > static char *timeserver = NULL;
> > > -static struct sockaddr_in timeserver_addr;
> > > +static struct sockaddr_storage timeserver_addr;
> > > static gint poll_id = 0;
> > > static gint timeout_id = 0;
> > > static guint retries = 0;
> > >
> > > -static void send_packet(int fd, const char *server, uint32_t timeout);
> > > +static void send_packet(int fd, const char *server, uint32_t timeout,
> > int family);
> > >
> > > static void next_server(void)
> > > {
> > > @@ -143,17 +143,21 @@ static gboolean send_timeout(gpointer user_data)
> > > if (retries++ == NTP_SEND_RETRIES)
> > > next_server();
> > > else
> > > - send_packet(transmit_fd, timeserver, timeout << 1);
> > > + send_packet(transmit_fd, timeserver, timeout << 1,
> > timeserver_addr.ss_family);
> > >
> > > return FALSE;
> > > }
> > >
> > > -static void send_packet(int fd, const char *server, uint32_t timeout)
> > > +static void send_packet(int fd, const char *server, uint32_t timeout,
> > int family)
> >
> > Instead of supplying a char *server, why don't we give a struct
> > sockaddr* instead? What's the purpose of carrying the server
> > "name" (nah, the IP address as a string), if it is already resolved in
> > the calling function? BTW, it is available as timeserver_addr, so do we
> > really need any of this information here?
> >
>
> Yes it makes sense but I am not sure sockaddr * is the one we should us. It
> will not be able to hold IPv6 address which is 16 bytes. So I guess
> sockaddr_storage* would be the right thing. Do you agree? If you look i
> changed type of timeserver_addr to sockaddr_storage. Do you agree with this?
>
> /* Structure describing a generic socket address. */
> struct sockaddr
> {
> __SOCKADDR_COMMON (sa_); /* Common data: address family and length.
> */
> char sa_data[14]; /* Address data. */
> };
>
>
You should never instantiate (== have a variable "struct sockaddr
myaddr") because there is not enough space as you noticed. You either
have a "struct sockaddr_in myaddr" or "struct sockaddr_in6 myaddr" and
then you just cast "struct sockaddr *" to correct variable.
There is no need to use sockaddr_storage here.
>
> > > {
> > > struct ntp_msg msg;
> > > - struct sockaddr_in addr;
> > > + struct sockaddr_in in4addr;
> > > + struct sockaddr_in6 in6addr;
> > > + struct sockaddr * addr;
> > > struct timeval transmit_timeval;
> > > ssize_t len;
> > > + int size;
> > > + unsigned char * addrptr;
> > >
> > > /*
> > > * At some point, we could specify the actual system precision
> > with:
> > > @@ -168,10 +172,29 @@ static void send_packet(int fd, const char
> > *server, uint32_t timeout)
> > > msg.poll = 10; // max
> > > msg.precision = NTP_PRECISION_S;
> > >
> > > - memset(&addr, 0, sizeof(addr));
> > > - addr.sin_family = AF_INET;
> > > - addr.sin_port = htons(123);
> > > - addr.sin_addr.s_addr = inet_addr(server);
> > > + if (family == AF_INET) {
> > > + memset(&in4addr, 0, sizeof(in4addr));
> > > + in4addr.sin_family = AF_INET;
> > > + in4addr.sin_port = htons(123);
> > > + size = sizeof(in4addr);
> > > + addrptr = (unsigned char *)&in4addr.sin_addr.s_addr;
> > > + addr = (struct sockaddr *)&in4addr;
> > > + } else if (family == AF_INET6){
> > > + memset(&in6addr, 0, sizeof(in6addr));
> > > + in6addr.sin6_family = AF_INET6;
> > > + in6addr.sin6_port = htons(123);
> > > + size = sizeof(in6addr);
> > > + addrptr = in6addr.sin6_addr.__in6_u.__u6_addr8;
> > > + addr = (struct sockaddr *)&in6addr;
> > > + } else {
> > > + DBG("wrong family type");
> > > + return;
> > > + }
> > > + if (inet_pton(family, server, addrptr) == 0)
> > > + {
> > > + DBG("cannot convert ip address string");
> > > + return;
> > > + }
> >
> > The above is unnecessary. You already have timeserver_addr set or the
> > function gets a sockaddr * to use.
> >
>
> Agreed. If we pass sockaddr_storage*.
No, sockaddr * is enough.
>
> >
> > > gettimeofday(&transmit_timeval, NULL);
> > > clock_gettime(CLOCK_MONOTONIC, &mtx_time);
> > > @@ -180,7 +203,7 @@ static void send_packet(int fd, const char *server,
> > uint32_t timeout)
> > > msg.xmttime.fraction = htonl(transmit_timeval.tv_usec * 1000);
> > >
> > > len = sendto(fd, &msg, sizeof(msg), MSG_DONTWAIT,
> > > - &addr, sizeof(addr));
> > > + addr, size);
> >
> > Use the stored timeserver_addr or supplied sockaddr * family information
> > to set the size to either sizeof(struct sockaddr_in) or sizeof(struct
> > sockaddr_in6).
> >
> I guess this is what i am doing. But will double confirm.
>
> >
> > > if (len < 0) {
> > > connman_error("Time request for server %s failed (%d/%s)",
> > > server, errno, strerror(errno));
> > > @@ -213,7 +236,7 @@ static gboolean next_poll(gpointer user_data)
> > > if (!timeserver || transmit_fd == 0)
> > > return FALSE;
> > >
> > > - send_packet(transmit_fd, timeserver, NTP_SEND_TIMEOUT);
> > > + send_packet(transmit_fd, timeserver, NTP_SEND_TIMEOUT,
> > timeserver_addr.ss_family);
> > >
> > > return FALSE;
> > > }
> > > @@ -363,7 +386,7 @@ static gboolean received_data(GIOChannel *channel,
> > GIOCondition condition,
> > > gpointer user_data)
> > > {
> > > unsigned char buf[128];
> > > - struct sockaddr_in sender_addr;
> > > + struct sockaddr_storage sender_addr;
> > > struct msghdr msg;
> > > struct iovec iov;
> > > struct cmsghdr *cmsg;
> > > @@ -396,9 +419,18 @@ static gboolean received_data(GIOChannel *channel,
> > GIOCondition condition,
> > > if (len < 0)
> > > return TRUE;
> > >
> > > - if (timeserver_addr.sin_addr.s_addr != sender_addr.sin_addr.s_addr)
> > > - /* only accept messages from the timeserver */
> > > + if (sender_addr.ss_family == AF_INET) {
> > > + if (((struct sockaddr_in
> > *)×erver_addr)->sin_addr.s_addr != ((struct sockaddr_in
> > *)&sender_addr)->sin_addr.s_addr)
> > > + return TRUE;
> > > + } else if(sender_addr.ss_family == AF_INET6) {
> > > + if (memcmp(((struct sockaddr_in6
> > *)×erver_addr)->sin6_addr.__in6_u.__u6_addr8,
> > > + ((struct sockaddr_in6
> > *)&sender_addr)->sin6_addr.__in6_u.__u6_addr8,
> > > + 16) != 0)
> >
> > Use memcmp for both of these. First check address families, if they
> > match the size can be deduced (for example as above) and have only a
> > single memcmp to do the matching.
> >
> Agreed.
>
> >
> > > + return TRUE;
> > > + } else {
> > > + connman_error("Not a valid family type");
> > > return TRUE;
> > > + }
> > >
> > > tv = NULL;
> > > clock_gettime(CLOCK_MONOTONIC, &mrx_time);
> > > @@ -422,36 +454,78 @@ static gboolean received_data(GIOChannel *channel,
> > GIOCondition condition,
> > > static void start_ntp(char *server)
> > > {
> > > GIOChannel *channel;
> > > - struct sockaddr_in addr;
> > > + struct sockaddr * addr;
> > > + struct sockaddr_in in4addr;
> > > + struct sockaddr_in6 in6addr;
> > > + struct addrinfo hint;
> > > + struct addrinfo *info;
> > > + int family;
> > > int tos = IPTOS_LOWDELAY, timestamp = 1;
> > > + int size;
> > > + int ret;
> > >
> > > if (!server)
> > > return;
> > >
> > > - DBG("server %s", server);
> > > + memset(&hint, 0, sizeof(hint));
> > > + hint.ai_family = AF_UNSPEC;
> > > + hint.ai_flags = AI_NUMERICHOST;
> > > + ret = getaddrinfo(server, NULL, &hint, &info);
> > > +
> > > + if (ret) {
> > > + connman_error("cannot get server info");
> > > + return;
> > > + }
> > > +
> > > + family = info->ai_family;
> > > + freeaddrinfo(info);
> >
> > Before throwing away info, the address is already available as
> > ->sin6_addr or ->sin_addr. See man getaddrinfo. Store the address and
> > the address family in timeserver_addr.
> >
> > I guess this may not be correct as getaddrinfo gives us a pointer to
> sockaddr which may not be able to contain the 16 byte IPv6 address. Do you
> agree? I guess using inet_pton is the best way.
>
> > > +
> > > + DBG("server %s family %d", server, family);
> > >
> > > if (channel_watch > 0)
> > > goto send;
> > >
> > > - transmit_fd = socket(PF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0);
> > > - if (transmit_fd < 0) {
> > > + transmit_fd = socket(family, SOCK_DGRAM | SOCK_CLOEXEC, 0);
> > > + if (transmit_fd <= 0) {
> > > connman_error("Failed to open time server socket");
> > > return;
> > > }
> > >
> > > - memset(&addr, 0, sizeof(addr));
> > > - addr.sin_family = AF_INET;
> > > + if (family == AF_INET) {
> > > + memset(&in4addr, 0, sizeof(in4addr));
> > > + in4addr.sin_family = family;
> > > + addr = (struct sockaddr *)&in4addr;
> > > + size = sizeof(in4addr);
> > > + if (inet_pton(family, server, &(((struct sockaddr_in
> > *)×erver_addr)->sin_addr.s_addr)) == 0) {
> > > + DBG("cannot convert ipv4 address string");
> > > + }
> > > + } else if (family == AF_INET6) {
> > > + memset(&in6addr, 0, sizeof(in6addr));
> > > + in6addr.sin6_family = family;
> > > + addr = (struct sockaddr *)&in6addr;
> > > + size = sizeof(in6addr);
> > > + if (inet_pton(family, server, ((struct sockaddr_in6
> > *)×erver_addr)->sin6_addr.__in6_u.__u6_addr8) == 0) {
> > > + DBG("cannot convert ipv6 address string");
> > > + }
> > > + } else {
> > > + connman_error("Family not correct");
> > > + return;
> > > + }
> >
> > No need for the above, look into the 'info' supplied to getaddrinfo()
> > above.
> >
> > > - if (bind(transmit_fd, (struct sockaddr *) &addr, sizeof(addr)) <
> > 0) {
> > > + timeserver_addr.ss_family = family;
> > > +
> > > + if (bind(transmit_fd, (struct sockaddr *) addr, size) < 0) {
> > > connman_error("Failed to bind time server socket");
> > > close(transmit_fd);
> > > return;
> > > }
> > >
> > > - if (setsockopt(transmit_fd, IPPROTO_IP, IP_TOS, &tos, sizeof(tos))
> > < 0) {
> > > - connman_error("Failed to set type of service option");
> > > - close(transmit_fd);
> > > - return;
> > > + if (family == AF_INET) {
> > > + if (setsockopt(transmit_fd, IPPROTO_IP, IP_TOS, &tos,
> > sizeof(tos)) < 0) {
> > > + connman_error("Failed to set type of service
> > option");
> > > + close(transmit_fd);
> > > + return;
> > > + }
> > > }
> > >
> > > if (setsockopt(transmit_fd, SOL_SOCKET, SO_TIMESTAMP, ×tamp,
> > > @@ -479,7 +553,7 @@ static void start_ntp(char *server)
> > > g_io_channel_unref(channel);
> > >
> > > send:
> > > - send_packet(transmit_fd, server, NTP_SEND_TIMEOUT);
> > > + send_packet(transmit_fd, server, NTP_SEND_TIMEOUT, family);
> > > }
> > >
> > > int __connman_ntp_start(char *server)
> > > @@ -493,7 +567,6 @@ int __connman_ntp_start(char *server)
> > > g_free(timeserver);
> > >
> > > timeserver = g_strdup(server);
> > > - timeserver_addr.sin_addr.s_addr = inet_addr(server);
> > >
> > > start_ntp(timeserver);
> > >
> >
> > Patrik
> >
> > Regards
> >
> Naveen
>
Cheers,
Jukka
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