From: Masatake YAMATO <yamato@redhat.com>
Date: Mon, 7 Mar 2022 13:19:28 +0000 (+0900)
Subject: lsfd: fill ENDPOINTS column for FIFOs
X-Git-Tag: v2.39-rc1~709^2~2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=5211d5a18082c52c31dfc92b3c710e8e32c8ef2c;p=thirdparty%2Futil-linux.git

lsfd: fill ENDPOINTS column for FIFOs

For FIFO type files, lsof can fill ENDPOINTS as following:

  _PID_,_COMMAND_,_ASSOC_[-r][-w]

Example output:

  $ dd if=/dev/zero | nc -l 127.0.0.1 9091 > /dev/null &
  [1] 1707808 1707809

  $ ./lsfd -p "1707808 1707809" -o+ENDPOINTS -Q '(type == "FIFO")'
  COMMAND     PID   USER ASSOC MODE TYPE SOURCE MNTID    INODE NAME            ENDPOINTS
  dd      1707808 yamato     1  -w- FIFO pipefs    14 73477636 pipe:[73477636] 1707809,nc,0r-
  nc      1707809 yamato     0  r-- FIFO pipefs    14 73477636 pipe:[73477636] 1707808,dd,1-w

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

diff --git a/misc-utils/lsfd-fifo.c b/misc-utils/lsfd-fifo.c
index 63eb18c7c0..3799313cdb 100644
--- a/misc-utils/lsfd-fifo.c
+++ b/misc-utils/lsfd-fifo.c
@@ -25,6 +25,26 @@
 
 #include "lsfd.h"
 
+struct fifo {
+	struct file file;
+	struct ipc_endpoint endpoint;
+};
+
+struct fifo_ipc {
+	struct ipc ipc;
+	ino_t ino;
+};
+
+static inline char *fifo_xstrendpoint(struct file *file)
+{
+	char *str = NULL;
+	xasprintf(&str, "%d,%s,%d%c%c",
+		  file->proc->pid, file->proc->command, file->association,
+		  (file->mode & S_IRUSR)? 'r': '-',
+		  (file->mode & S_IWUSR)? 'w': '-');
+	return str;
+}
+
 static bool fifo_fill_column(struct proc *proc __attribute__((__unused__)),
 			     struct file *file,
 			     struct libscols_line *ln,
@@ -45,6 +65,24 @@ static bool fifo_fill_column(struct proc *proc __attribute__((__unused__)),
 			break;
 		}
 		return false;
+	case COL_ENDPOINTS: {
+		struct fifo *this = (struct fifo *)file;
+		struct list_head *e;
+		char *estr;
+		list_for_each_backwardly(e, &this->endpoint.ipc->endpoints) {
+			struct fifo *other = list_entry(e, struct fifo, endpoint.endpoints);
+			if (this == other)
+				continue;
+			if (str)
+				xstrputc(&str, '\n');
+			estr = fifo_xstrendpoint(&other->file);
+			xstrappend(&str, estr);
+			free(estr);
+		}
+		if (!str)
+			return false;
+		break;
+	}
 	default:
 		return false;
 	}
@@ -56,9 +94,55 @@ static bool fifo_fill_column(struct proc *proc __attribute__((__unused__)),
 	return true;
 }
 
+static unsigned int fifo_get_hash(struct file *file)
+{
+	return (unsigned int)(file->stat.st_ino % UINT_MAX);
+}
+
+static bool fifo_is_suitable_ipc(struct ipc *ipc, struct file *file)
+{
+	return ((struct fifo_ipc *)ipc)->ino == file->stat.st_ino;
+}
+
+static struct ipc_class *fifo_get_ipc_class(struct file *file __attribute__((__unused__)))
+{
+	static struct ipc_class fifo_ipc_class = {
+		.get_hash = fifo_get_hash,
+		.is_suitable_ipc = fifo_is_suitable_ipc,
+		.free = NULL,
+	};
+	return &fifo_ipc_class;
+}
+
+static void fifo_initialize_content(struct file *file)
+{
+	struct fifo *fifo = (struct fifo *)file;
+	struct ipc *ipc;
+	unsigned int hash;
+
+	INIT_LIST_HEAD(&fifo->endpoint.endpoints);
+	ipc = get_ipc(file);
+	if (ipc)
+		goto link;
+
+	ipc = xmalloc(sizeof(struct fifo_ipc));
+	ipc->class = fifo_get_ipc_class(file);
+	INIT_LIST_HEAD(&ipc->endpoints);
+	INIT_LIST_HEAD(&ipc->ipcs);
+	((struct fifo_ipc *)ipc)->ino = file->stat.st_ino;
+
+	hash = fifo_get_hash(file);
+	add_ipc(ipc, hash);
+ link:
+	fifo->endpoint.ipc = ipc;
+	list_add(&fifo->endpoint.endpoints, &ipc->endpoints);
+}
+
 const struct file_class fifo_class = {
 	.super = &file_class,
-	.size = sizeof(struct file),
+	.size = sizeof(struct fifo),
 	.fill_column = fifo_fill_column,
+	.initialize_content = fifo_initialize_content,
 	.free_content = NULL,
+	.get_ipc_class = fifo_get_ipc_class,
 };
diff --git a/misc-utils/lsfd.1.adoc b/misc-utils/lsfd.1.adoc
index ca9d8287d4..146908c33f 100644
--- a/misc-utils/lsfd.1.adoc
+++ b/misc-utils/lsfd.1.adoc
@@ -135,6 +135,17 @@ Device type (_blk_, _char_, or _nodev_).
 
 ENDPOINT <__string__>::
 IPC endpoints information communicated with the fd.
+The format of the column depends on the object associated
+with the fd:
+
+ FIFO type::: _PID_,_COMMAND_,_ASSOC_[-r][-w]
+
+ The last characters ([-r][-w]) represents the read and/or
+ write mode of the endpoint.
+
+*lsfd* collects endpoints within the processes that
+*lsfd* scans; *lsfd* may miss some endpoints
+if you limits the processes with *-p* option.
 
 FD <__number__>::
 File descriptor for the file.
diff --git a/misc-utils/lsfd.c b/misc-utils/lsfd.c
index 88b9205cb1..0022ead6dc 100644
--- a/misc-utils/lsfd.c
+++ b/misc-utils/lsfd.c
@@ -133,7 +133,7 @@ static struct colinfo infos[] = {
 		N_("ID of device containing file") },
 	[COL_DEVTYPE] = { "DEVTYPE",  0, SCOLS_FL_RIGHT, SCOLS_JSON_STRING,
 		N_("device type (blk, char, or nodev)") },
-	[COL_ENDPOINTS] ={"ENDPOINTS",0,              0, SCOLS_JSON_STRING,
+	[COL_ENDPOINTS] ={"ENDPOINTS",0,  SCOLS_FL_WRAP, SCOLS_JSON_STRING,
 		N_("IPC endpoints information communicated with the fd") },
 	[COL_FLAGS]   = { "FLAGS",    0, SCOLS_FL_RIGHT, SCOLS_JSON_STRING,
 		N_("flags specified when opening the file") },
@@ -347,8 +347,16 @@ static struct libscols_column *add_column(struct libscols_table *tb, const struc
 	int flags = col->flags;
 
 	cl = scols_table_new_column(tb, col->name, col->whint, flags);
-	if (cl)
+	if (cl) {
 		scols_column_set_json_type(cl, col->json_type);
+		if (col->flags & SCOLS_FL_WRAP) {
+			scols_column_set_wrapfunc(cl,
+						  scols_wrapnl_chunksize,
+						  scols_wrapnl_nextchunk,
+						  NULL);
+			scols_column_set_safechars(cl, "\n");
+		}
+	}
 
 	return cl;
 }