X-Git-Url: https://git.ozlabs.org/?a=blobdiff_plain;f=pppd%2Fsys-linux.c;h=7beb977484f5ddca6859e10f79dcab039e26ea9c;hb=76016e1b948b7d9675b4e0750d1f943d96d9523b;hp=94e5a19ed4c67cc44f97b2257c3b0d57b4ed15a0;hpb=80b8744eb42c7493794f3e3fe0bf1ce14f53e6dd;p=ppp.git diff --git a/pppd/sys-linux.c b/pppd/sys-linux.c index 94e5a19..7beb977 100644 --- a/pppd/sys-linux.c +++ b/pppd/sys-linux.c @@ -81,6 +81,7 @@ #include #include #include +#include #include #include @@ -125,13 +126,12 @@ #include #include -#include -#include +#include -#ifdef PPP_WITH_IPV6CP #include #include #include + /* Attempt at retaining compile-support with older than 4.7 kernels, or kernels * where RTM_NEWSTATS isn't defined for whatever reason. */ @@ -139,9 +139,10 @@ #define RTM_NEWSTATS 92 #define RTM_GETSTATS 94 #define IFLA_STATS_LINK_64 1 -#endif /* PPP_WITH_IPV6CP */ +#endif #include + /* glibc versions prior to 2.24 do not define SOL_NETLINK */ #ifndef SOL_NETLINK #define SOL_NETLINK 270 @@ -151,16 +152,25 @@ #ifndef NETLINK_CAP_ACK #define NETLINK_CAP_ACK 10 #endif + +/* linux kernel versions prior to 4.7 do not define/support IFLA_PPP_DEV_FD */ +#ifndef IFLA_PPP_MAX +/* IFLA_PPP_DEV_FD is declared as enum when IFLA_PPP_MAX is defined */ +#define IFLA_PPP_DEV_FD 1 #endif #include "pppd.h" #include "fsm.h" #include "ipcp.h" -#ifdef PPP_FILTER +#ifdef PPP_WITH_IPV6CP +#include "eui64.h" +#endif /* PPP_WITH_IPV6CP */ + +#ifdef PPP_WITH_FILTER #include #include -#endif /* PPP_FILTER */ +#endif /* PPP_WITH_FILTER */ #ifdef LOCKLIB #include @@ -288,6 +298,147 @@ extern int dfl_route_metric; memset ((char *) &(addr), '\0', sizeof(addr)); \ addr.sa_family = (family); + +/* + * rtnetlink_msg - send rtnetlink message, receive response + * and return received error code: + * 0 - success + * positive value - error during sending / receiving message + * negative value - rtnetlink responce error code + */ +static int rtnetlink_msg(const char *desc, int *shared_fd, void *nlreq, size_t nlreq_len, void *nlresp_data, size_t *nlresp_size, unsigned nlresp_type) +{ + struct nlresp_hdr { + struct nlmsghdr nlh; + struct nlmsgerr nlerr; + } nlresp_hdr; + struct sockaddr_nl nladdr; + struct iovec iov[2]; + struct msghdr msg; + ssize_t nlresp_len; + int one; + int fd; + + if (shared_fd && *shared_fd >= 0) { + fd = *shared_fd; + } else { + fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); + if (fd < 0) { + error("rtnetlink_msg: socket(NETLINK_ROUTE): %m (line %d)", __LINE__); + return 1; + } + + /* + * Tell kernel to not send to us payload of acknowledgment error message. + * NETLINK_CAP_ACK option is supported since Linux kernel version 4.3 and + * older kernel versions always send full payload in acknowledgment netlink + * message. We ignore payload of this message as we need only error code, + * to check if our set remote peer address request succeeded or failed. + * So ignore return value from the following setsockopt() call as setting + * option NETLINK_CAP_ACK means for us just a kernel hint / optimization. + */ + one = 1; + setsockopt(fd, SOL_NETLINK, NETLINK_CAP_ACK, &one, sizeof(one)); + + memset(&nladdr, 0, sizeof(nladdr)); + nladdr.nl_family = AF_NETLINK; + + if (bind(fd, (struct sockaddr *)&nladdr, sizeof(nladdr)) < 0) { + error("rtnetlink_msg: bind(AF_NETLINK): %m (line %d)", __LINE__); + close(fd); + return 1; + } + + if (shared_fd) + *shared_fd = fd; + } + + memset(&nladdr, 0, sizeof(nladdr)); + nladdr.nl_family = AF_NETLINK; + + memset(&iov[0], 0, sizeof(iov[0])); + iov[0].iov_base = nlreq; + iov[0].iov_len = nlreq_len; + + memset(&msg, 0, sizeof(msg)); + msg.msg_name = &nladdr; + msg.msg_namelen = sizeof(nladdr); + msg.msg_iov = &iov[0]; + msg.msg_iovlen = 1; + + if (sendmsg(fd, &msg, 0) < 0) { + error("rtnetlink_msg: sendmsg(%s): %m (line %d)", desc, __LINE__); + if (!shared_fd) + close(fd); + return 1; + } + + memset(iov, 0, sizeof(iov)); + iov[0].iov_base = &nlresp_hdr; + if (nlresp_size && *nlresp_size > sizeof(nlresp_hdr)) { + iov[0].iov_len = offsetof(struct nlresp_hdr, nlerr); + iov[1].iov_base = nlresp_data; + iov[1].iov_len = *nlresp_size; + } else { + iov[0].iov_len = sizeof(nlresp_hdr); + } + + memset(&msg, 0, sizeof(msg)); + msg.msg_name = &nladdr; + msg.msg_namelen = sizeof(nladdr); + msg.msg_iov = iov; + msg.msg_iovlen = (nlresp_size && *nlresp_size > sizeof(nlresp_hdr)) ? 2 : 1; + + nlresp_len = recvmsg(fd, &msg, 0); + + if (!shared_fd) + close(fd); + + if (nlresp_len < 0) { + error("rtnetlink_msg: recvmsg(%s): %m (line %d)", desc, __LINE__); + return 1; + } + + if (nladdr.nl_family != AF_NETLINK) { + error("rtnetlink_msg: recvmsg(%s): Not a netlink packet (line %d)", desc, __LINE__); + return 1; + } + + if (!nlresp_size) { + if ((size_t)nlresp_len < sizeof(nlresp_hdr) || nlresp_hdr.nlh.nlmsg_len < sizeof(nlresp_hdr)) { + error("rtnetlink_msg: recvmsg(%s): Acknowledgment netlink packet too short (line %d)", desc, __LINE__); + return 1; + } + + /* acknowledgment packet for NLM_F_ACK is NLMSG_ERROR */ + if (nlresp_hdr.nlh.nlmsg_type != NLMSG_ERROR) { + error("rtnetlink_msg: recvmsg(%s): Not an acknowledgment netlink packet (line %d)", desc, __LINE__); + return 1; + } + } + + if (nlresp_size) { + if (*nlresp_size > sizeof(nlresp_hdr)) + memcpy((unsigned char *)&nlresp_hdr + offsetof(struct nlresp_hdr, nlerr), nlresp_data, sizeof(nlresp_hdr.nlerr)); + else + memcpy(nlresp_data, (unsigned char *)&nlresp_hdr + offsetof(struct nlresp_hdr, nlerr), *nlresp_size); + } + + /* error == 0 indicates success, negative value is errno code */ + if (nlresp_hdr.nlh.nlmsg_type == NLMSG_ERROR && nlresp_hdr.nlerr.error) + return nlresp_hdr.nlerr.error; + + if (nlresp_size) { + if (nlresp_hdr.nlh.nlmsg_type != nlresp_type) { + error("rtnetlink_msg: recvmsg(%s): Not a netlink packet of type 0x%x (line %d)", desc, nlresp_type, __LINE__); + return 1; + } + *nlresp_size = nlresp_len - offsetof(struct nlresp_hdr, nlerr); + } + + return 0; +} + /* * Determine if the PPP connection should still be present. */ @@ -660,6 +811,84 @@ void generic_disestablish_ppp(int dev_fd) } } +/* + * make_ppp_unit_rtnetlink - register a new ppp network interface for ppp_dev_fd + * with specified req_ifname via rtnetlink. Interface name req_ifname must not + * be empty. Custom ppp unit id req_unit is ignored and kernel choose some free. + */ +static int make_ppp_unit_rtnetlink(void) +{ + struct { + struct nlmsghdr nlh; + struct ifinfomsg ifm; + struct { + struct rtattr rta; + char ifname[IFNAMSIZ]; + } ifn; + struct { + struct rtattr rta; + struct { + struct rtattr rta; + char ifkind[sizeof("ppp")]; + } ifik; + struct { + struct rtattr rta; + struct { + struct rtattr rta; + union { + int ppp_dev_fd; + } ppp; + } ifdata[1]; + } ifid; + } ifli; + } nlreq; + int resp; + + memset(&nlreq, 0, sizeof(nlreq)); + nlreq.nlh.nlmsg_len = sizeof(nlreq); + nlreq.nlh.nlmsg_type = RTM_NEWLINK; + nlreq.nlh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | NLM_F_EXCL | NLM_F_CREATE; + nlreq.ifm.ifi_family = AF_UNSPEC; + nlreq.ifm.ifi_type = ARPHRD_NETROM; + nlreq.ifn.rta.rta_len = sizeof(nlreq.ifn); + nlreq.ifn.rta.rta_type = IFLA_IFNAME; + strlcpy(nlreq.ifn.ifname, req_ifname, sizeof(nlreq.ifn.ifname)); + nlreq.ifli.rta.rta_len = sizeof(nlreq.ifli); + nlreq.ifli.rta.rta_type = IFLA_LINKINFO; + nlreq.ifli.ifik.rta.rta_len = sizeof(nlreq.ifli.ifik); + nlreq.ifli.ifik.rta.rta_type = IFLA_INFO_KIND; + strcpy(nlreq.ifli.ifik.ifkind, "ppp"); + nlreq.ifli.ifid.rta.rta_len = sizeof(nlreq.ifli.ifid); + nlreq.ifli.ifid.rta.rta_type = IFLA_INFO_DATA; + nlreq.ifli.ifid.ifdata[0].rta.rta_len = sizeof(nlreq.ifli.ifid.ifdata[0]); + nlreq.ifli.ifid.ifdata[0].rta.rta_type = IFLA_PPP_DEV_FD; + nlreq.ifli.ifid.ifdata[0].ppp.ppp_dev_fd = ppp_dev_fd; + + /* + * See kernel function ppp_nl_newlink(), which may return -EBUSY to prevent + * possible deadlock in kernel and ask userspace to retry request again. + */ + do { + resp = rtnetlink_msg("RTM_NEWLINK/NLM_F_CREATE", NULL, &nlreq, sizeof(nlreq), NULL, NULL, 0); + } while (resp == -EBUSY); + + if (resp) { + /* + * Linux kernel versions prior to 4.7 do not support creating ppp + * interfaces via rtnetlink API and therefore error response is + * expected. On older kernel versions do not show this error message. + * When error is different than EEXIST then pppd tries to fallback to + * the old ioctl method. + */ + errno = (resp < 0) ? -resp : EINVAL; + if (kernel_version >= KVERSION(4,7,0)) + error("Couldn't create ppp interface %s: %m", req_ifname); + return 0; + } + + return 1; +} + /* * make_ppp_unit - make a new ppp unit for ppp_dev_fd. * Assumes new_style_driver. @@ -680,6 +909,33 @@ static int make_ppp_unit(void) || fcntl(ppp_dev_fd, F_SETFL, flags | O_NONBLOCK) == -1) warn("Couldn't set /dev/ppp to nonblock: %m"); + /* + * Via rtnetlink it is possible to create ppp network interface with + * custom ifname atomically. But it is not possible to specify custom + * ppp unit id. + * + * Tools like systemd, udev or NetworkManager are trying to query + * interface attributes based on interface name immediately when new + * network interface is created. And therefore immediate interface + * renaming is causing issues. + * + * So use rtnetlink API only when user requested custom ifname. It will + * avoid system issues with interface renaming. + */ + if (req_unit == -1 && req_ifname[0] != '\0' && kernel_version >= KVERSION(2,1,16)) { + if (make_ppp_unit_rtnetlink()) { + if (ioctl(ppp_dev_fd, PPPIOCGUNIT, &ifunit)) + fatal("Couldn't retrieve PPP unit id: %m"); + return 0; + } + /* + * If interface with requested name already exist return error + * otherwise fallback to old ioctl method. + */ + if (errno == EEXIST) + return -1; + } + ifunit = req_unit; x = ioctl(ppp_dev_fd, PPPIOCNEWUNIT, &ifunit); if (x < 0 && req_unit >= 0 && errno == EEXIST) { @@ -687,6 +943,11 @@ static int make_ppp_unit(void) ifunit = -1; x = ioctl(ppp_dev_fd, PPPIOCNEWUNIT, &ifunit); } + if (x < 0 && errno == EEXIST) { + srand(time(NULL) * getpid()); + ifunit = rand() % 10000; + x = ioctl(ppp_dev_fd, PPPIOCNEWUNIT, &ifunit); + } if (x < 0) error("Couldn't create new ppp unit: %m"); @@ -1425,7 +1686,7 @@ void ccp_flags_set (int unit, int isopen, int isup) modify_flags(ppp_dev_fd, SC_CCP_OPEN|SC_CCP_UP, x); } -#ifdef PPP_FILTER +#ifdef PPP_WITH_FILTER /* * set_filters - set the active and pass filters in the kernel driver. */ @@ -1450,7 +1711,7 @@ int set_filters(struct bpf_program *pass, struct bpf_program *active) } return 1; } -#endif /* PPP_FILTER */ +#endif /* PPP_WITH_FILTER */ /******************************************************************** * @@ -1475,20 +1736,21 @@ get_ppp_stats_ioctl(int u, struct pppd_stats *stats) static u_int32_t iwraps = 0; static u_int32_t owraps = 0; - struct ifpppstatsreq req; + struct ifreq req; + struct ppp_stats data; memset (&req, 0, sizeof (req)); - req.stats_ptr = (caddr_t) &req.stats; - strlcpy(req.ifr__name, ifname, sizeof(req.ifr__name)); + req.ifr_data = (caddr_t) &data; + strlcpy(req.ifr_name, ifname, sizeof(req.ifr_name)); if (ioctl(sock_fd, SIOCGPPPSTATS, &req) < 0) { error("Couldn't get PPP statistics: %m"); return 0; } - stats->bytes_in = req.stats.p.ppp_ibytes; - stats->bytes_out = req.stats.p.ppp_obytes; - stats->pkts_in = req.stats.p.ppp_ipackets; - stats->pkts_out = req.stats.p.ppp_opackets; + stats->bytes_in = data.p.ppp_ibytes; + stats->bytes_out = data.p.ppp_obytes; + stats->pkts_in = data.p.ppp_ipackets; + stats->pkts_out = data.p.ppp_opackets; if (stats->bytes_in < previbytes) ++iwraps; @@ -1511,123 +1773,55 @@ get_ppp_stats_ioctl(int u, struct pppd_stats *stats) static int get_ppp_stats_rtnetlink(int u, struct pppd_stats *stats) { - static int rtnl_fd = -1; + static int fd = -1; - struct sockaddr_nl nladdr; struct { struct nlmsghdr nlh; struct if_stats_msg ifsm; } nlreq; - struct nlresp { - struct nlmsghdr nlh; - union { - struct { - struct nlmsgerr nlerr; - char __end_err[0]; - }; - struct { - struct rtmsg rth; - struct { - /* We only case about these first fields from rtnl_link_stats64 */ - uint64_t rx_packets; - uint64_t tx_packets; - uint64_t rx_bytes; - uint64_t tx_bytes; - } stats; - char __end_stats[0]; - }; - }; - } nlresp; - ssize_t nlresplen; - struct iovec iov; - struct msghdr msg; - - memset(&nladdr, 0, sizeof(nladdr)); - nladdr.nl_family = AF_NETLINK; - - if (rtnl_fd < 0) { - rtnl_fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); - if (rtnl_fd < 0) { - error("get_ppp_stats_rtnetlink: error creating NETLINK socket: %m (line %d)", __LINE__); - return 0; - } - - if (bind(rtnl_fd, (struct sockaddr *)&nladdr, sizeof(nladdr)) < 0) { - error("get_ppp_stats_rtnetlink: bind(AF_NETLINK): %m (line %d)", __LINE__); - goto err; - } - } + struct { + struct rtmsg rth; + struct { + /* We only case about these first fields from rtnl_link_stats64 */ + uint64_t rx_packets; + uint64_t tx_packets; + uint64_t rx_bytes; + uint64_t tx_bytes; + } stats; + } nlresp_data; + size_t nlresp_size; + int resp; memset(&nlreq, 0, sizeof(nlreq)); nlreq.nlh.nlmsg_len = sizeof(nlreq); nlreq.nlh.nlmsg_type = RTM_GETSTATS; nlreq.nlh.nlmsg_flags = NLM_F_REQUEST; - nlreq.ifsm.ifindex = if_nametoindex(ifname); nlreq.ifsm.filter_mask = IFLA_STATS_LINK_64; - memset(&iov, 0, sizeof(iov)); - iov.iov_base = &nlreq; - iov.iov_len = sizeof(nlreq); - - memset(&msg, 0, sizeof(msg)); - msg.msg_name = &nladdr; - msg.msg_namelen = sizeof(nladdr); - msg.msg_iov = &iov; - msg.msg_iovlen = 1; - - if (sendmsg(rtnl_fd, &msg, 0) < 0) { - error("get_ppp_stats_rtnetlink: sendmsg(RTM_GETSTATS): %m (line %d)", __LINE__); - goto err; - } - - /* We just need to repoint to IOV ... everything else stays the same */ - iov.iov_base = &nlresp; - iov.iov_len = sizeof(nlresp); - - nlresplen = recvmsg(rtnl_fd, &msg, 0); - - if (nlresplen < 0) { - error("get_ppp_stats_rtnetlink: recvmsg(RTM_GETSTATS): %m (line %d)", __LINE__); - goto err; - } - - if (nlresplen < sizeof(nlresp.nlh)) { - error("get_ppp_stats_rtnetlink: Netlink response message was incomplete (line %d)", __LINE__); - goto err; - } - - if (nlresp.nlh.nlmsg_type == NLMSG_ERROR) { - if (nlresplen < offsetof(struct nlresp, __end_err)) { - if (kernel_version >= KVERSION(4,7,0)) - error("get_ppp_stats_rtnetlink: Netlink responded with error: %s (line %d)", strerror(-nlresp.nlerr.error), __LINE__); - } else { - error("get_ppp_stats_rtnetlink: Netlink responded with an error message, but the nlmsgerr structure is incomplete (line %d).", - __LINE__); - } - goto err; - } - - if (nlresp.nlh.nlmsg_type != RTM_NEWSTATS) { - error("get_ppp_stats_rtnetlink: Expected RTM_NEWSTATS response, found something else (mlmsg_type %d, line %d)", - nlresp.nlh.nlmsg_type, __LINE__); - goto err; + nlresp_size = sizeof(nlresp_data); + resp = rtnetlink_msg("RTM_GETSTATS/NLM_F_REQUEST", &fd, &nlreq, sizeof(nlreq), &nlresp_data, &nlresp_size, RTM_NEWSTATS); + if (resp) { + errno = (resp < 0) ? -resp : EINVAL; + if (kernel_version >= KVERSION(4,7,0)) + error("get_ppp_stats_rtnetlink: %m (line %d)", __LINE__); + goto err; } - if (nlresplen < offsetof(struct nlresp, __end_stats)) { + if (nlresp_size < sizeof(nlresp_data)) { error("get_ppp_stats_rtnetlink: Obtained an insufficiently sized rtnl_link_stats64 struct from the kernel (line %d).", __LINE__); goto err; } - stats->bytes_in = nlresp.stats.rx_bytes; - stats->bytes_out = nlresp.stats.tx_bytes; - stats->pkts_in = nlresp.stats.rx_packets; - stats->pkts_out = nlresp.stats.tx_packets; + stats->bytes_in = nlresp_data.stats.rx_bytes; + stats->bytes_out = nlresp_data.stats.tx_bytes; + stats->pkts_in = nlresp_data.stats.rx_packets; + stats->pkts_out = nlresp_data.stats.tx_packets; return 1; err: - close(rtnl_fd); - rtnl_fd = -1; + close(fd); + fd = -1; return 0; } @@ -3164,43 +3358,7 @@ static int sif6addr_rtnetlink(unsigned int iface, eui64_t our_eui64, eui64_t his struct in6_addr addr; } addrs[2]; } nlreq; - struct { - struct nlmsghdr nlh; - struct nlmsgerr nlerr; - } nlresp; - struct sockaddr_nl nladdr; - struct iovec iov; - struct msghdr msg; - ssize_t nlresplen; - int one; - int fd; - - fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); - if (fd < 0) { - error("sif6addr_rtnetlink: socket(NETLINK_ROUTE): %m (line %d)", __LINE__); - return 0; - } - - /* - * Tell kernel to not send to us payload of acknowledgment error message. - * NETLINK_CAP_ACK option is supported since Linux kernel version 4.3 and - * older kernel versions always send full payload in acknowledgment netlink - * message. We ignore payload of this message as we need only error code, - * to check if our set remote peer address request succeeded or failed. - * So ignore return value from the following setsockopt() call as setting - * option NETLINK_CAP_ACK means for us just a kernel hint / optimization. - */ - one = 1; - setsockopt(fd, SOL_NETLINK, NETLINK_CAP_ACK, &one, sizeof(one)); - - memset(&nladdr, 0, sizeof(nladdr)); - nladdr.nl_family = AF_NETLINK; - - if (bind(fd, (struct sockaddr *)&nladdr, sizeof(nladdr)) < 0) { - error("sif6addr_rtnetlink: bind(AF_NETLINK): %m (line %d)", __LINE__); - close(fd); - return 0; - } + int resp; memset(&nlreq, 0, sizeof(nlreq)); nlreq.nlh.nlmsg_len = sizeof(nlreq); @@ -3230,71 +3388,17 @@ static int sif6addr_rtnetlink(unsigned int iface, eui64_t our_eui64, eui64_t his else IN6_LLADDR_FROM_EUI64(nlreq.addrs[1].addr, our_eui64); - memset(&nladdr, 0, sizeof(nladdr)); - nladdr.nl_family = AF_NETLINK; - - memset(&iov, 0, sizeof(iov)); - iov.iov_base = &nlreq; - iov.iov_len = sizeof(nlreq); - - memset(&msg, 0, sizeof(msg)); - msg.msg_name = &nladdr; - msg.msg_namelen = sizeof(nladdr); - msg.msg_iov = &iov; - msg.msg_iovlen = 1; - - if (sendmsg(fd, &msg, 0) < 0) { - error("sif6addr_rtnetlink: sendmsg(RTM_NEWADDR/NLM_F_CREATE): %m (line %d)", __LINE__); - close(fd); - return 0; - } - - memset(&iov, 0, sizeof(iov)); - iov.iov_base = &nlresp; - iov.iov_len = sizeof(nlresp); - - memset(&msg, 0, sizeof(msg)); - msg.msg_name = &nladdr; - msg.msg_namelen = sizeof(nladdr); - msg.msg_iov = &iov; - msg.msg_iovlen = 1; - - nlresplen = recvmsg(fd, &msg, 0); - - if (nlresplen < 0) { - error("sif6addr_rtnetlink: recvmsg(NLM_F_ACK): %m (line %d)", __LINE__); - close(fd); - return 0; - } - - close(fd); - - if (nladdr.nl_family != AF_NETLINK) { - error("sif6addr_rtnetlink: recvmsg(NLM_F_ACK): Not a netlink packet (line %d)", __LINE__); - return 0; - } - - if ((size_t)nlresplen != sizeof(nlresp) || nlresp.nlh.nlmsg_len < sizeof(nlresp)) { - error("sif6addr_rtnetlink: recvmsg(NLM_F_ACK): Acknowledgment netlink packet too short (line %d)", __LINE__); - return 0; - } - - /* acknowledgment packet for NLM_F_ACK is NLMSG_ERROR */ - if (nlresp.nlh.nlmsg_type != NLMSG_ERROR) { - error("sif6addr_rtnetlink: recvmsg(NLM_F_ACK): Not an acknowledgment netlink packet (line %d)", __LINE__); - return 0; - } - - /* error == 0 indicates success, negative value is errno code */ - if (nlresp.nlerr.error != 0) { + resp = rtnetlink_msg("RTM_NEWADDR/NLM_F_CREATE", NULL, &nlreq, sizeof(nlreq), NULL, NULL, 0); + if (resp) { /* * Linux kernel versions prior 3.11 do not support setting IPv6 peer * addresses and error response is expected. On older kernel versions * do not show this error message. On error pppd tries to fallback to * the old IOCTL method. */ + errno = (resp < 0) ? -resp : EINVAL; if (kernel_version >= KVERSION(3,11,0)) - error("sif6addr_rtnetlink: %s (line %d)", strerror(-nlresp.nlerr.error), __LINE__); + error("sif6addr_rtnetlink: %m (line %d)", __LINE__); return 0; }