Messages in this thread | | | From | KY Srinivasan <> | Subject | RE: [PATCH] Tools: hv: fix send/recv buffer allocation | Date | Thu, 1 Aug 2013 14:33:49 +0000 |
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> -----Original Message----- > From: Olaf Hering [mailto:olaf@aepfle.de] > Sent: Thursday, August 01, 2013 8:34 AM > To: KY Srinivasan; gregkh@linuxfoundation.org > Cc: linux-kernel@vger.kernel.org; Olaf Hering > Subject: [PATCH] Tools: hv: fix send/recv buffer allocation > > hv_kvp_daemon fails to start in current openSuSE 13.1 snapshots because > the kvp_send_buffer is too small to hold cn_msg+hv_kvp_msg, the very > first sendmsg returns with EFAULT. In addition it fixes the Network info > tab in Windows Server 2012R2 in SLES11. > > Adjust the code in kvp and vss daemon to allocate the needed buffers at > runtime. To keep the code simple, the buffer_len includes also the > nlmsghdr, although only the recv_buffer needs this extra space. > > Signed-off-by: Olaf Hering <olaf@aepfle.de> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
> --- > tools/hv/hv_kvp_daemon.c | 15 ++++++++++++--- > tools/hv/hv_vss_daemon.c | 15 ++++++++++++--- > 2 files changed, 24 insertions(+), 6 deletions(-) > > diff --git a/tools/hv/hv_kvp_daemon.c b/tools/hv/hv_kvp_daemon.c > index 07819bf..657c1d2 100644 > --- a/tools/hv/hv_kvp_daemon.c > +++ b/tools/hv/hv_kvp_daemon.c > @@ -79,8 +79,6 @@ enum { > DNS > }; > > -static char kvp_send_buffer[4096]; > -static char kvp_recv_buffer[4096 * 2]; > static struct sockaddr_nl addr; > static int in_hand_shake = 1; > > @@ -1437,10 +1435,21 @@ int main(void) > int pool; > char *if_name; > struct hv_kvp_ipaddr_value *kvp_ip_val; > + char *kvp_send_buffer; > + char *kvp_recv_buffer; > + size_t kvp_recv_buffer_len; > > daemon(1, 0); > openlog("KVP", 0, LOG_USER); > syslog(LOG_INFO, "KVP starting; pid is:%d", getpid()); > + > + kvp_recv_buffer_len = NLMSG_HDRLEN + sizeof(struct cn_msg) + > sizeof(struct hv_kvp_msg); > + kvp_send_buffer = calloc(1, kvp_recv_buffer_len); > + kvp_recv_buffer = calloc(1, kvp_recv_buffer_len); > + if (!(kvp_send_buffer && kvp_recv_buffer)) { > + syslog(LOG_ERR, "Failed to allocate netlink buffers"); > + exit(EXIT_FAILURE); > + } > /* > * Retrieve OS release information. > */ > @@ -1514,7 +1523,7 @@ int main(void) > continue; > } > > - len = recvfrom(fd, kvp_recv_buffer, sizeof(kvp_recv_buffer), 0, > + len = recvfrom(fd, kvp_recv_buffer, kvp_recv_buffer_len, 0, > addr_p, &addr_l); > > if (len < 0) { > diff --git a/tools/hv/hv_vss_daemon.c b/tools/hv/hv_vss_daemon.c > index fea03a3..4c34675 100644 > --- a/tools/hv/hv_vss_daemon.c > +++ b/tools/hv/hv_vss_daemon.c > @@ -38,8 +38,6 @@ > #include <linux/netlink.h> > #include <syslog.h> > > -static char vss_recv_buffer[4096]; > -static char vss_send_buffer[4096]; > static struct sockaddr_nl addr; > > #ifndef SOL_NETLINK > @@ -147,6 +145,9 @@ int main(void) > struct cn_msg *incoming_cn_msg; > int op; > struct hv_vss_msg *vss_msg; > + char *vss_send_buffer; > + char *vss_recv_buffer; > + size_t vss_recv_buffer_len; > > if (daemon(1, 0)) > return 1; > @@ -154,6 +155,14 @@ int main(void) > openlog("Hyper-V VSS", 0, LOG_USER); > syslog(LOG_INFO, "VSS starting; pid is:%d", getpid()); > > + vss_recv_buffer_len = NLMSG_HDRLEN + sizeof(struct cn_msg) + > sizeof(struct hv_vss_msg); > + vss_send_buffer = calloc(1, vss_recv_buffer_len); > + vss_recv_buffer = calloc(1, vss_recv_buffer_len); > + if (!(vss_send_buffer && vss_recv_buffer)) { > + syslog(LOG_ERR, "Failed to allocate netlink buffers"); > + exit(EXIT_FAILURE); > + } > + > fd = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_CONNECTOR); > if (fd < 0) { > syslog(LOG_ERR, "netlink socket creation failed; error:%d", fd); > @@ -201,7 +210,7 @@ int main(void) > pfd.revents = 0; > poll(&pfd, 1, -1); > > - len = recvfrom(fd, vss_recv_buffer, sizeof(vss_recv_buffer), 0, > + len = recvfrom(fd, vss_recv_buffer, vss_recv_buffer_len, 0, > addr_p, &addr_l); > > if (len < 0) { > >
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