lsfd: fill ENDPOINTS column of unix socket using UNIX_DIAG_PEER information

An example output:

   # ./lsfd -Q '((PID == 1) || (PID == 1896)) && (TYPE == "UNIX-STREAM") && ((FD == 1) || (FD == 278))' -o+ENDPOINTS
   COMMAND        PID USER ASSOC  XMODE        TYPE SOURCE MNTID INODE NAME                                             ENDPOINTS
   systemd          1 root   278 rw---m UNIX-STREAM sockfs     9 37012 state=connected path=/run/systemd/journal/stdout 1896,ModemManager,1
   ModemManager  1896 root     1 rw---- UNIX-STREAM sockfs     9 43126 state=connected                                  1,systemd,278
                                                                                                                        1870458,systemd-journal,68

Signed-off-by: Masatake YAMATO <yamato@redhat.com>

diff --git a/misc-utils/lsfd-sock-xinfo.c b/misc-utils/lsfd-sock-xinfo.c
index 3e7ff94eee493a3444405d72c900d082fd5b98c6..301da27889388d067ed1949f68fd5885fcc3be9a 100644 (file)
--- a/misc-utils/lsfd-sock-xinfo.c
+++ b/misc-utils/lsfd-sock-xinfo.c
@@ -393,11 +393,18 @@ static void send_diag_request(int diagsd, void *req, size_t req_size,
 /*
  * UNIX
  */
+struct unix_ipc {
+       struct ipc ipc;
+       ino_t inode;
+       ino_t ipeer;
+};
+
 struct unix_xinfo {
        struct sock_xinfo sock;
        int acceptcon;  /* flags */
        uint16_t type;
        uint8_t  st;
+       struct unix_ipc *unix_ipc;
        char path[
                  UNIX_PATH_MAX
                  + 1           /* for @ */
@@ -475,15 +482,76 @@ static bool unix_get_listening(struct sock_xinfo *sock_xinfo,
        return ux->acceptcon;
 }
 
+static unsigned int unix_get_hash(struct file *file)
+{
+       return (unsigned int)(file->stat.st_ino % UINT_MAX);
+}
+
+static bool unix_is_suitable_ipc(struct ipc *ipc, struct file *file)
+{
+       return ((struct unix_ipc *)ipc)->inode == file->stat.st_ino;
+}
+
+/* For looking up an ipc struct for a sock inode, we need a sock strcuct
+ * for the inode. See the signature o get_ipc().
+ *
+ * However, there is a case that we have no sock strcuct for the inode;
+ * in the context we know only the sock inode.
+ * For the case, unix_make_dumy_sock() provides the way to make a
+ * dummy sock struct for the inode.
+ */
+static void unix_make_dumy_sock(struct sock *original, ino_t ino, struct sock *dummy)
+{
+       *dummy = *original;
+       dummy->file.stat.st_ino = ino;
+}
+
+static struct ipc_class unix_ipc_class = {
+       .size = sizeof(struct unix_ipc),
+       .get_hash = unix_get_hash,
+       .is_suitable_ipc = unix_is_suitable_ipc,
+       .free = NULL,
+};
+
+static struct ipc_class *unix_get_ipc_class(struct sock_xinfo *sock_xinfo __attribute__((__unused__)),
+                                           struct sock *sock __attribute__((__unused__)))
+{
+       return &unix_ipc_class;
+}
+
+static inline char *unix_xstrendpoint(struct sock *sock)
+{
+       char *str = NULL;
+       xasprintf(&str, "%d,%s,%d",
+                 sock->file.proc->pid, sock->file.proc->command, sock->file.association);
+       return str;
+}
+
+static struct ipc *unix_get_peer_ipc(struct unix_xinfo *ux,
+                                    struct sock *sock)
+{
+       struct unix_ipc *unix_ipc;
+       struct sock dummy_peer_sock;
+
+       unix_ipc = ux->unix_ipc;
+       if (!unix_ipc)
+               return NULL;
+
+       unix_make_dumy_sock(sock, unix_ipc->ipeer, &dummy_peer_sock);
+       return get_ipc(&dummy_peer_sock.file);
+}
+
 static bool unix_fill_column(struct proc *proc __attribute__((__unused__)),
                             struct sock_xinfo *sock_xinfo,
-                            struct sock *sock __attribute__((__unused__)),
+                            struct sock *sock,
                             struct libscols_line *ln __attribute__((__unused__)),
                             int column_id,
                             size_t column_index __attribute__((__unused__)),
                             char **str)
 {
        struct unix_xinfo *ux = (struct unix_xinfo *)sock_xinfo;
+       struct ipc *peer_ipc;
+       struct list_head *e;
 
        switch (column_id) {
        case COL_UNIX_PATH:
@@ -492,6 +560,24 @@ static bool unix_fill_column(struct proc *proc __attribute__((__unused__)),
                        return true;
                }
                break;
+       case COL_ENDPOINTS:
+               peer_ipc = unix_get_peer_ipc(ux, sock);
+               if (!peer_ipc)
+                       break;
+
+               list_for_each_backwardly(e, &peer_ipc->endpoints) {
+                       struct sock *peer_sock = list_entry(e, struct sock, endpoint.endpoints);
+                       char *estr;
+
+                       if (*str)
+                               xstrputc(str, '\n');
+                       estr = unix_xstrendpoint(peer_sock);
+                       xstrappend(str, estr);
+                       free(estr);
+               }
+               if (*str)
+                       return true;
+               break;
        }
 
        return false;
@@ -503,6 +589,7 @@ static const struct sock_xinfo_class unix_xinfo_class = {
        .get_state = unix_get_state,
        .get_listening = unix_get_listening,
        .fill_column = unix_fill_column,
+       .get_ipc_class = unix_get_ipc_class,
        .free = NULL,
 };
 
@@ -588,6 +675,7 @@ static bool handle_diag_unix(ino_t netns __attribute__((__unused__)),
        size_t rta_len;
        ino_t inode;
        struct sock_xinfo *xinfo;
+       struct unix_xinfo *unix_xinfo;
 
        if (diag->udiag_family != AF_UNIX)
                return false;
@@ -605,6 +693,7 @@ static bool handle_diag_unix(ino_t netns __attribute__((__unused__)),
 
        if (xinfo->class != &unix_xinfo_class)
                return true;
+       unix_xinfo = (struct unix_xinfo *)xinfo;
 
        rta_len = nlmsg_len - NLMSG_LENGTH(sizeof(*diag));
        for (struct rtattr *attr = (struct rtattr *)(diag + 1);
@@ -616,6 +705,16 @@ static bool handle_diag_unix(ino_t netns __attribute__((__unused__)),
                case UNIX_DIAG_NAME:
                        unix_refill_name(xinfo, RTA_DATA(attr), len);
                        break;
+
+               case UNIX_DIAG_PEER:
+                       if (len < 4)
+                               break;
+
+                       unix_xinfo->unix_ipc = (struct unix_ipc *)new_ipc(&unix_ipc_class);
+                       unix_xinfo->unix_ipc->inode = inode;
+                       unix_xinfo->unix_ipc->ipeer = (ino_t)(*(uint32_t *)RTA_DATA(attr));
+                       add_ipc(&unix_xinfo->unix_ipc->ipc, inode % UINT_MAX);
+                       break;
                }
        }
        return true;
@@ -626,7 +725,7 @@ static void load_xinfo_from_diag_unix(int diagsd, ino_t netns)
        struct unix_diag_req udr = {
                .sdiag_family = AF_UNIX,
                .udiag_states = -1, /* set the all bits. */
-               .udiag_show = UDIAG_SHOW_NAME,
+               .udiag_show = UDIAG_SHOW_NAME | UDIAG_SHOW_PEER,
        };
 
        send_diag_request(diagsd, &udr, sizeof(udr), handle_diag_unix, netns);