1#include <linux/compiler.h>
2#include <linux/kernel.h>
3#include <sys/types.h>
4#include <sys/stat.h>
5#include <unistd.h>
6#include <string.h>
7
8#include "data.h"
9#include "util.h"
10#include "debug.h"
11
12static bool check_pipe(struct perf_data_file *file)
13{
14	struct stat st;
15	bool is_pipe = false;
16	int fd = perf_data_file__is_read(file) ?
17		 STDIN_FILENO : STDOUT_FILENO;
18
19	if (!file->path) {
20		if (!fstat(fd, &st) && S_ISFIFO(st.st_mode))
21			is_pipe = true;
22	} else {
23		if (!strcmp(file->path, "-"))
24			is_pipe = true;
25	}
26
27	if (is_pipe)
28		file->fd = fd;
29
30	return file->is_pipe = is_pipe;
31}
32
33static int check_backup(struct perf_data_file *file)
34{
35	struct stat st;
36
37	if (!stat(file->path, &st) && st.st_size) {
38		/* TODO check errors properly */
39		char oldname[PATH_MAX];
40		snprintf(oldname, sizeof(oldname), "%s.old",
41			 file->path);
42		unlink(oldname);
43		rename(file->path, oldname);
44	}
45
46	return 0;
47}
48
49static int open_file_read(struct perf_data_file *file)
50{
51	struct stat st;
52	int fd;
53	char sbuf[STRERR_BUFSIZE];
54
55	fd = open(file->path, O_RDONLY);
56	if (fd < 0) {
57		int err = errno;
58
59		pr_err("failed to open %s: %s", file->path,
60			strerror_r(err, sbuf, sizeof(sbuf)));
61		if (err == ENOENT && !strcmp(file->path, "perf.data"))
62			pr_err("  (try 'perf record' first)");
63		pr_err("\n");
64		return -err;
65	}
66
67	if (fstat(fd, &st) < 0)
68		goto out_close;
69
70	if (!file->force && st.st_uid && (st.st_uid != geteuid())) {
71		pr_err("File %s not owned by current user or root (use -f to override)\n",
72		       file->path);
73		goto out_close;
74	}
75
76	if (!st.st_size) {
77		pr_info("zero-sized file (%s), nothing to do!\n",
78			file->path);
79		goto out_close;
80	}
81
82	file->size = st.st_size;
83	return fd;
84
85 out_close:
86	close(fd);
87	return -1;
88}
89
90static int open_file_write(struct perf_data_file *file)
91{
92	int fd;
93	char sbuf[STRERR_BUFSIZE];
94
95	if (check_backup(file))
96		return -1;
97
98	fd = open(file->path, O_CREAT|O_RDWR|O_TRUNC, S_IRUSR|S_IWUSR);
99
100	if (fd < 0)
101		pr_err("failed to open %s : %s\n", file->path,
102			strerror_r(errno, sbuf, sizeof(sbuf)));
103
104	return fd;
105}
106
107static int open_file(struct perf_data_file *file)
108{
109	int fd;
110
111	fd = perf_data_file__is_read(file) ?
112	     open_file_read(file) : open_file_write(file);
113
114	file->fd = fd;
115	return fd < 0 ? -1 : 0;
116}
117
118int perf_data_file__open(struct perf_data_file *file)
119{
120	if (check_pipe(file))
121		return 0;
122
123	if (!file->path)
124		file->path = "perf.data";
125
126	return open_file(file);
127}
128
129void perf_data_file__close(struct perf_data_file *file)
130{
131	close(file->fd);
132}
133
134ssize_t perf_data_file__write(struct perf_data_file *file,
135			      void *buf, size_t size)
136{
137	return writen(file->fd, buf, size);
138}
139