Hi Patrik,
Sorry for a very delayed reply on this thread. I do appreciate all your
feedback and I would send you the revised patch on Monday after testing it
for both IPv4 and IPv6 timeserver and all possible combinations.
On Thu, Oct 8, 2015 at 5:22 AM, Patrik Flykt <patrik.fl...@linux.intel.com>
wrote:
>
> Hi,
>
> On Tue, 2015-10-06 at 23:50 -0700, Naveen Singh wrote:
> > From: Naveen Singh <nav...@nestlabs.com>
> >
> > 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 | 139
> ++++++++++++++++++++++++++++++++++++++++++++++----------------
> > 1 file changed, 103 insertions(+), 36 deletions(-)
> >
> > diff --git a/src/ntp.c b/src/ntp.c
> > index 2c313a4..7858633 100644
> > --- a/src/ntp.c
> > +++ b/src/ntp.c
> > @@ -34,6 +34,7 @@
> > #include <netinet/in.h>
> > #include <netinet/ip.h>
> > #include <arpa/inet.h>
> > +#include <netdb.h>
> >
> > #include <glib.h>
> >
> > @@ -117,12 +118,12 @@ static struct timespec mtx_time;
> > static int transmit_fd = 0;
> >
> > static char *timeserver = NULL;
> > -static struct sockaddr_in timeserver_addr;
> > +static struct sockaddr_in6 timeserver_addr;
>
> Yes, this should be large enough.
>
> > 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, struct sockaddr *server, uint32_t
> timeout);
> >
> > static void next_server(void)
> > {
> > @@ -143,17 +144,18 @@ 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, (struct sockaddr
> *)×erver_addr, timeout << 1);
> >
> > return FALSE;
> > }
> >
> > -static void send_packet(int fd, const char *server, uint32_t timeout)
> > +static void send_packet(int fd, struct sockaddr *server, uint32_t
> timeout)
> > {
> > struct ntp_msg msg;
> > - struct sockaddr_in addr;
> > struct timeval transmit_timeval;
> > ssize_t len;
> > + int size;
> > + char ipaddrstring[28];
>
> The size is not correct. Use INET6_ADDRSTRLEN + 1 as it wants to be null
> terminated also.
>
Thanks for it. I made the change already.
>
> >
> > /*
> > * At some point, we could specify the actual system precision
> with:
> > @@ -168,10 +170,14 @@ 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 (server->sa_family == AF_INET) {
> > + size = sizeof(struct sockaddr_in);
> > + } else if (server->sa_family == AF_INET6){
> > + size = sizeof(struct sockaddr_in6);
> > + } else {
> > + connman_error("Family is neither ipv4 nor ipv6");
> > + return;
> > + }
> >
> > gettimeofday(&transmit_timeval, NULL);
> > clock_gettime(CLOCK_MONOTONIC, &mtx_time);
> > @@ -180,10 +186,18 @@ 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));
> > + server, size);
> > +
> > + if ((len < 0) || (len != sizeof(msg))) {
> > + inet_ntop(server->sa_family,
> > + (server->sa_family == AF_INET)?(void *)&(((struct
> sockaddr_in *)×erver_addr)->sin_addr):(void
> *)×erver_addr.sin6_addr,
> > + ipaddrstring,
> > + 28);
>
> This very complicated. In the previous block server->sa_family is
> already investigated, why not record the address of sin_addr or
> sin6_addr into a pointer already there? inet_ntop wants a void * anyway.
> inet_ntop is not needed right away, because...
>
I agree I have gotten rid of it and now I call inet_ntop twice as you
mentioned.
>
> > + }
> > +
> > if (len < 0) {
> > connman_error("Time request for server %s failed (%d/%s)",
> > - server, errno, strerror(errno));
> > + ipaddrstring, errno, strerror(errno));
>
> ...it can be used here in the log print, as it returns a non-null
> pointer as well. So we would have connman_error(...,
> inet_ntop(server->sa_family, addr, &ipaddrstr, sizeof(ipaddrstr)), ...);
>
> >
> > if (errno == ENETUNREACH)
> > __connman_timeserver_sync_next();
> > @@ -192,7 +206,7 @@ static void send_packet(int fd, const char *server,
> uint32_t timeout)
> > }
> >
> > if (len != sizeof(msg)) {
> > - connman_error("Broken time request for server %s", server);
> > + connman_error("Broken time request for server %s",
> ipaddrstring);
>
> Same here. Yes, it duplicates the print but makes the logic a bit easier
> to follow.
>
I have done this.
>
> > return;
> > }
> >
> > @@ -213,7 +227,7 @@ 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, (struct sockaddr *)×erver_addr,
> NTP_SEND_TIMEOUT);
> >
> > return FALSE;
> > }
> > @@ -363,7 +377,7 @@ static gboolean received_data(GIOChannel *channel,
> GIOCondition condition,
> > gpointer user_data)
> > {
> > unsigned char buf[128];
> > - struct sockaddr_in sender_addr;
> > + struct sockaddr_in6 sender_addr;
> > struct msghdr msg;
> > struct iovec iov;
> > struct cmsghdr *cmsg;
> > @@ -372,6 +386,9 @@ static gboolean received_data(GIOChannel *channel,
> GIOCondition condition,
> > char aux[128];
> > ssize_t len;
> > int fd;
> > + int size;
> > + void * addr_ptr;
> > + void * src_ptr;
> >
> > if (condition & (G_IO_HUP | G_IO_ERR | G_IO_NVAL)) {
> > connman_error("Problem with timer server channel");
> > @@ -396,8 +413,20 @@ 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.sin6_family == AF_INET) {
> > + size = 4;
> > + addr_ptr = (void *)&((struct sockaddr_in
> *)×erver_addr)->sin_addr.s_addr;
> > + src_ptr = (void *)&((struct sockaddr_in
> *)&sender_addr)->sin_addr.s_addr;
>
> The cast to (void *) doesn't seem to be necessary and ->sin_addr should
> be enough as well.
>
> > + } else if(sender_addr.sin6_family == AF_INET6) {
>
> Space after 'if'
>
> > + size = 16;
> > + addr_ptr = (void *)((struct sockaddr_in6
> *)×erver_addr)->sin6_addr.__in6_u.__u6_addr8;
> > + src_ptr = (void *)((struct sockaddr_in6
> *)&sender_addr)->sin6_addr.__in6_u.__u6_addr8;
>
> As above, (void *) and ->sin6_addr.
> > + } else {
> > + connman_error("Not a valid family type");
> > + return TRUE;
> > + }
> > +
> > + if(memcmp(addr_ptr, src_ptr, size) != 0)
> > return TRUE;
> >
> > tv = NULL;
> > @@ -422,36 +451,75 @@ static gboolean received_data(GIOChannel *channel,
> GIOCondition condition,
> > static void start_ntp(char *server)
> > {
> > GIOChannel *channel;
> > - struct sockaddr_in addr;
> > + struct addrinfo hint;
> > + struct addrinfo *info;
> > + struct sockaddr * addr;
> > + struct sockaddr_in in4addr;
> > + struct sockaddr_in6 in6addr;
> > + int size;
> > + int family;
> > int tos = IPTOS_LOWDELAY, timestamp = 1;
> > + int ret;
> >
> > if (!server)
> > return;
> >
> > - DBG("server %s", server);
> > -
> > - if (channel_watch > 0)
> > - goto send;
> > + memset(&hint, 0, sizeof(hint));
> > + hint.ai_family = AF_UNSPEC;
> > + hint.ai_socktype = SOCK_DGRAM;
> > + hint.ai_flags = AI_NUMERICHOST | AI_PASSIVE;
> > + ret = getaddrinfo(server, NULL, &hint, &info);
> >
> > - transmit_fd = socket(PF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0);
> > - if (transmit_fd < 0) {
> > - connman_error("Failed to open time server socket");
> > + if (ret) {
> > + connman_error("cannot get server info");
> > return;
> > }
> >
> > - memset(&addr, 0, sizeof(addr));
> > - addr.sin_family = AF_INET;
> > -
> > - if (bind(transmit_fd, (struct sockaddr *) &addr, sizeof(addr)) <
> 0) {
> > - connman_error("Failed to bind time server socket");
> > - close(transmit_fd);
> > + family = info->ai_family;
>
> > + if (family == AF_INET) {
> > + memcpy((struct sockaddr_in *)×erver_addr, ((struct
> sockaddr_in *)info->ai_addr), info->ai_addrlen);
>
> memcopy expects void * so the cast to (struct sockaddr_in *) seems
> totally unnecessary in both places. Do one common memcopy after setting
> the needed variable values outside of these 'if's.
>
> > + ((struct sockaddr_in *)×erver_addr)->sin_port =
> htons(123);
>
> I didn't notice sin_port being used anywhere, so this is not needed?
>
This is being used in current code so I decided to follow the current code.
In send_packet look for following line:
addr.sin_port = htons(123);
>
> > + memset(&in4addr, 0, sizeof(in4addr));
>
> Set addr's type to struct sockaddr_in6. Then the memset can be done
> above as before and only once.
>
> > + in4addr.sin_family = family;
> > + addr = (struct sockaddr *)&in4addr;
> > + size = sizeof(in4addr);
>
> size is needed, but why the pointer?
>
> > + } else if (family == AF_INET6) {
> > + memcpy(×erver_addr, ((struct sockaddr_in6
> *)info->ai_addr), info->ai_addrlen);
> > + timeserver_addr.sin6_port = htons(123);
> > + memset(&in6addr, 0, sizeof(in6addr));
> > + in6addr.sin6_family = family;
> > + addr = (struct sockaddr *)&in6addr;
> > + size = sizeof(in6addr);
>
> Same comments apply as in the other branch.
>
> > + } else {
> > + connman_error("Family is neither ipv4 nor ipv6");
> > return;
> > }
> > + freeaddrinfo(info);
> >
> > - 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;
> > + DBG("server %s family %d", server, family);
> > +
> > + if (channel_watch > 0)
> > + goto send;
> > +
> > + transmit_fd = socket(family, SOCK_DGRAM | SOCK_CLOEXEC, 0);
> > +
> > + if (transmit_fd <= 0) {
> > + connman_error("Failed to open time server socket");
> > + return;
> > + }
> > +
> > + if (bind(transmit_fd, (struct sockaddr *) addr, size) < 0) {
> > + connman_error("Failed to bind time server socket");
> > + 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 +547,7 @@ static void start_ntp(char *server)
> > g_io_channel_unref(channel);
> >
> > send:
> > - send_packet(transmit_fd, server, NTP_SEND_TIMEOUT);
> > + send_packet(transmit_fd, (struct sockaddr*)×erver_addr,
> NTP_SEND_TIMEOUT);
> > }
> >
> > int __connman_ntp_start(char *server)
> > @@ -493,7 +561,6 @@ 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);
> >
>
> Cheers,
>
> Patrik
>
Thanks
Naveen
>
>
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