nspawn: a bench of special fileystems that should not be shifted

[elogind.git] / src / basic / socket-util.c

diff --git a/src/basic/socket-util.c b/src/basic/socket-util.c
index ee08a9c9c89ec2ad03de26438f9956ddb7ce29b5..5efd09fb8b4d71c9660520727bf1f232bdc40aae 100644 (file)
--- a/src/basic/socket-util.c
+++ b/src/basic/socket-util.c
@@ -1,5 +1,3 @@
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
 /***
   This file is part of systemd.
 
@@ -44,6 +42,7 @@
 #include "socket-util.h"
 #include "string-table.h"
 #include "string-util.h"
+#include "strv.h"
 #include "user-util.h"
 #include "util.h"
 
@@ -442,17 +441,10 @@ const char* socket_address_get_path(const SocketAddress *a) {
 #endif // 0
 
 bool socket_ipv6_is_supported(void) {
-        _cleanup_free_ char *l = NULL;
-
-        if (access("/sys/module/ipv6", F_OK) != 0)
+        if (access("/proc/net/sockstat6", F_OK) != 0)
                 return false;
 
-        /* If we can't check "disable" parameter, assume enabled */
-        if (read_one_line_file("/sys/module/ipv6/parameters/disable", &l) < 0)
-                return true;
-
-        /* If module was loaded with disable=1 no IPv6 available */
-        return l[0] == '0';
+        return true;
 }
 
 #if 0 /// UNNEEDED by elogind
@@ -809,6 +801,42 @@ static const char* const ip_tos_table[] = {
 DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(ip_tos, int, 0xff);
 #endif // 0
 
+bool ifname_valid(const char *p) {
+        bool numeric = true;
+
+        /* Checks whether a network interface name is valid. This is inspired by dev_valid_name() in the kernel sources
+         * but slightly stricter, as we only allow non-control, non-space ASCII characters in the interface name. We
+         * also don't permit names that only container numbers, to avoid confusion with numeric interface indexes. */
+
+        if (isempty(p))
+                return false;
+
+        if (strlen(p) >= IFNAMSIZ)
+                return false;
+
+        if (STR_IN_SET(p, ".", ".."))
+                return false;
+
+        while (*p) {
+                if ((unsigned char) *p >= 127U)
+                        return false;
+
+                if ((unsigned char) *p <= 32U)
+                        return false;
+
+                if (*p == ':' || *p == '/')
+                        return false;
+
+                numeric = numeric && (*p >= '0' && *p <= '9');
+                p++;
+        }
+
+        if (numeric)
+                return false;
+
+        return true;
+}
+
 int getpeercred(int fd, struct ucred *ucred) {
         socklen_t n = sizeof(struct ucred);
         struct ucred u;
@@ -886,14 +914,13 @@ int send_one_fd_sa(
                 struct cmsghdr cmsghdr;
                 uint8_t buf[CMSG_SPACE(sizeof(int))];
         } control = {};
-        struct cmsghdr *cmsg;
-
         struct msghdr mh = {
                 .msg_name = (struct sockaddr*) sa,
                 .msg_namelen = len,
                 .msg_control = &control,
                 .msg_controllen = sizeof(control),
         };
+        struct cmsghdr *cmsg;
 
         assert(transport_fd >= 0);
         assert(fd >= 0);
@@ -953,4 +980,77 @@ int receive_one_fd(int transport_fd, int flags) {
 
         return *(int*) CMSG_DATA(found);
 }
+
+ssize_t next_datagram_size_fd(int fd) {
+        ssize_t l;
+        int k;
+
+        /* This is a bit like FIONREAD/SIOCINQ, however a bit more powerful. The difference being: recv(MSG_PEEK) will
+         * actually cause the next datagram in the queue to be validated regarding checksums, which FIONREAD doesn't
+         * do. This difference is actually of major importance as we need to be sure that the size returned here
+         * actually matches what we will read with recvmsg() next, as otherwise we might end up allocating a buffer of
+         * the wrong size. */
+
+        l = recv(fd, NULL, 0, MSG_PEEK|MSG_TRUNC);
+        if (l < 0) {
+                if (errno == EOPNOTSUPP)
+                        goto fallback;
+
+                return -errno;
+        }
+        if (l == 0)
+                goto fallback;
+
+        return l;
+
+fallback:
+        k = 0;
+
+        /* Some sockets (AF_PACKET) do not support null-sized recv() with MSG_TRUNC set, let's fall back to FIONREAD
+         * for them. Checksums don't matter for raw sockets anyway, hence this should be fine. */
+
+        if (ioctl(fd, FIONREAD, &k) < 0)
+                return -errno;
+
+        return (ssize_t) k;
+}
+
+int flush_accept(int fd) {
+
+        struct pollfd pollfd = {
+                .fd = fd,
+                .events = POLLIN,
+        };
+        int r;
+
+
+        /* Similar to flush_fd() but flushes all incoming connection by accepting them and immediately closing them. */
+
+        for (;;) {
+                int cfd;
+
+                r = poll(&pollfd, 1, 0);
+                if (r < 0) {
+                        if (errno == EINTR)
+                                continue;
+
+                        return -errno;
+
+                } else if (r == 0)
+                        return 0;
+
+                cfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC);
+                if (cfd < 0) {
+                        if (errno == EINTR)
+                                continue;
+
+                        if (errno == EAGAIN)
+                                return 0;
+
+                        return -errno;
+                }
+
+                close(cfd);
+        }
+}
 #endif // 0