[libvirt] [PATCH] macvtap: convert send / recv function to use libnl

In a second step I am converting the netlink send/receive function to use libnl. I tested this with 802.1Qbg profiles and my test server and did not see a regression. Caveat: The online documentation of libnl talks about nl_socket_alloc() but the header file provides nl_handle_alloc() -- this could be a hint to a possible problem between libnl versions... http://www.infradead.org/~tgr/libnl/doc/group__socket.html versus http://libnl.sourcearchive.com/documentation/1.1/group__socket_gf903c9ea0... Signed-off-by: Stefan Berger <stefanb(a)us.ibm.com&gt; --- src/util/macvtap.c | 89 ++++++++++++++++++----------------------------------- 1 file changed, 31 insertions(+), 58 deletions(-) Index: libvirt-acl/src/util/macvtap.c =================================================================== --- libvirt-acl.orig/src/util/macvtap.c +++ libvirt-acl/src/util/macvtap.c @@ -82,22 +82,6 @@ enum virVirtualPortOp { }; -static int nlOpen(void) -{ - int fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); - if (fd < 0) - virReportSystemError(errno, - "%s",_("cannot open netlink socket")); - return fd; -} - - -static void nlClose(int fd) -{ - close(fd); -} - - /** * nlComm: * @nlmsg: pointer to netlink message @@ -111,8 +95,8 @@ static void nlClose(int fd) * buffer will be returned. */ static -int nlComm(struct nlmsghdr *nlmsg, - char **respbuf, unsigned int *respbuflen, +int nlComm(struct nl_msg *nl_msg, + unsigned char **respbuf, unsigned int *respbuflen, int nl_pid) { int rc = 0; @@ -121,24 +105,29 @@ int nlComm(struct nlmsghdr *nlmsg, .nl_pid = nl_pid, .nl_groups = 0, }; - int rcvChunkSize = 1024; // expecting less than that - int rcvoffset = 0; ssize_t nbytes; struct timeval tv = { .tv_sec = NETLINK_ACK_TIMEOUT_S, }; fd_set readfds; - int fd = nlOpen(); + int fd; int n; + struct nl_handle *nlhandle = nl_handle_alloc(); + struct nlmsghdr *nlmsg = nlmsg_hdr(nl_msg); - if (fd < 0) + if (!nlhandle) return -1; + if (nl_connect(nlhandle, NETLINK_ROUTE) < 0) { + rc = -1; + goto err_exit; + } + + nlmsg_set_dst(nl_msg, &nladdr); + nlmsg->nlmsg_pid = getpid(); - nlmsg->nlmsg_flags |= NLM_F_ACK; - nbytes = sendto(fd, (void *)nlmsg, nlmsg->nlmsg_len, 0, - (struct sockaddr *)&nladdr, sizeof(nladdr)); + nbytes = nl_send_auto_complete(nlhandle, nl_msg); if (nbytes < 0) { virReportSystemError(errno, "%s", _("cannot send to netlink socket")); @@ -146,6 +135,8 @@ int nlComm(struct nlmsghdr *nlmsg, goto err_exit; } + fd = nl_socket_get_fd(nlhandle); + FD_ZERO(&readfds); FD_SET(fd, &readfds); @@ -161,28 +152,9 @@ int nlComm(struct nlmsghdr *nlmsg, goto err_exit; } - while (1) { - if (VIR_REALLOC_N(*respbuf, rcvoffset+rcvChunkSize) < 0) { - virReportOOMError(); - rc = -1; - goto err_exit; - } - - socklen_t addrlen = sizeof(nladdr); - nbytes = recvfrom(fd, &((*respbuf)[rcvoffset]), rcvChunkSize, 0, - (struct sockaddr *)&nladdr, &addrlen); - if (nbytes < 0) { - if (errno == EAGAIN || errno == EINTR) - continue; - virReportSystemError(errno, "%s", - _("error receiving from netlink socket")); - rc = -1; - goto err_exit; - } - rcvoffset += nbytes; - break; - } - *respbuflen = rcvoffset; + *respbuflen = nl_recv(nlhandle, &nladdr, respbuf, NULL); + if (*respbuflen <= 0) + rc = -1; err_exit: if (rc == -1) { @@ -191,7 +163,8 @@ err_exit: *respbuflen = 0; } - nlClose(fd); + nl_handle_destroy(nlhandle); + return rc; } @@ -211,7 +184,7 @@ link_add(const char *type, struct nlmsgerr *err; struct ifinfomsg ifinfo = { .ifi_family = AF_UNSPEC }; int ifindex; - char *recvbuf = NULL; + unsigned char *recvbuf = NULL; unsigned int recvbuflen; struct nl_msg *nl_msg; struct nlattr *linkinfo, *info_data; @@ -260,7 +233,7 @@ link_add(const char *type, nla_nest_end(nl_msg, linkinfo); - if (nlComm(nlmsg_hdr(nl_msg), &recvbuf, &recvbuflen, 0) < 0) { + if (nlComm(nl_msg, &recvbuf, &recvbuflen, 0) < 0) { rc = -1; goto err_exit; } @@ -332,7 +305,7 @@ link_del(const char *ifname) struct nlmsghdr *resp; struct nlmsgerr *err; struct ifinfomsg ifinfo = { .ifi_family = AF_UNSPEC }; - char *recvbuf = NULL; + unsigned char *recvbuf = NULL; unsigned int recvbuflen; struct nl_msg *nl_msg; @@ -349,7 +322,7 @@ link_del(const char *ifname) if (nla_put(nl_msg, IFLA_IFNAME, strlen(ifname)+1, ifname) < 0) goto buffer_too_small; - if (nlComm(nlmsg_hdr(nl_msg), &recvbuf, &recvbuflen, 0) < 0) { + if (nlComm(nl_msg, &recvbuf, &recvbuflen, 0) < 0) { rc = -1; goto err_exit; } @@ -746,7 +719,7 @@ getLldpadPid(void) { static int link_dump(bool nltarget_kernel, const char *ifname, int ifindex, - struct nlattr **tb, char **recvbuf) + struct nlattr **tb, unsigned char **recvbuf) { int rc = 0; struct nlmsghdr *resp; @@ -783,7 +756,7 @@ link_dump(bool nltarget_kernel, const ch } } - if (nlComm(nlmsg_hdr(nl_msg), recvbuf, &recvbuflen, pid) < 0) { + if (nlComm(nl_msg, recvbuf, &recvbuflen, pid) < 0) { rc = -1; goto err_exit; } @@ -869,7 +842,7 @@ ifaceGetNthParent(int ifindex, const cha { int rc; struct nlattr *tb[IFLA_MAX + 1] = { NULL, }; - char *recvbuf = NULL; + unsigned char *recvbuf = NULL; bool end = false; unsigned int i = 0; @@ -1029,7 +1002,7 @@ doPortProfileOpSetLink(bool nltarget_ker .ifi_family = AF_UNSPEC, .ifi_index = ifindex, }; - char *recvbuf = NULL; + unsigned char *recvbuf = NULL; unsigned int recvbuflen = 0; uint32_t pid = 0; struct nl_msg *nl_msg; @@ -1140,7 +1113,7 @@ doPortProfileOpSetLink(bool nltarget_ker } } - if (nlComm(nlmsg_hdr(nl_msg), &recvbuf, &recvbuflen, pid) < 0) { + if (nlComm(nl_msg, &recvbuf, &recvbuflen, pid) < 0) { rc = -1; goto err_exit; } @@ -1208,7 +1181,7 @@ doPortProfileOpCommon(bool nltarget_kern uint8_t op) { int rc; - char *recvbuf = NULL; + unsigned char *recvbuf = NULL; struct nlattr *tb[IFLA_MAX + 1] = { NULL , }; int repeats = STATUS_POLL_TIMEOUT_USEC / STATUS_POLL_INTERVL_USEC; uint16_t status = 0;