Commit | Line | Data |
---|---|---|
d07a80dc JA |
1 | /* |
2 | * Use vmsplice to splice data from a pipe to user space memory. | |
3 | */ | |
4 | #include <stdio.h> | |
5 | #include <stdlib.h> | |
6 | #include <unistd.h> | |
7 | #include <limits.h> | |
8 | #include <string.h> | |
9 | #include <getopt.h> | |
0a6ff83b | 10 | #include <fcntl.h> |
d07a80dc JA |
11 | #include <sys/poll.h> |
12 | #include <sys/types.h> | |
13 | ||
14 | #include "splice.h" | |
15 | ||
16 | static int do_dump; | |
ef0e4210 JA |
17 | static int do_ascii; |
18 | static int do_zeromap; | |
d07a80dc JA |
19 | static int splice_flags; |
20 | ||
ef0e4210 JA |
21 | static int do_vmsplice_unmap(int fd, unsigned char *buf, int len) |
22 | { | |
23 | struct iovec iov = { | |
24 | .iov_base = buf, | |
25 | .iov_len = len, | |
26 | }; | |
27 | ||
28 | return svmsplice(fd, &iov, 1, SPLICE_F_UNMAP); | |
29 | } | |
30 | ||
31 | static int do_vmsplice(int fd, unsigned char **buf, int len) | |
d07a80dc JA |
32 | { |
33 | struct pollfd pfd = { .fd = fd, .events = POLLIN, }; | |
34 | struct iovec iov; | |
35 | int written; | |
36 | int ret; | |
37 | ||
ef0e4210 | 38 | iov.iov_base = *buf; |
d07a80dc JA |
39 | iov.iov_len = len; |
40 | ret = 0; | |
41 | ||
42 | while (len) { | |
43 | /* | |
44 | * in a real app you'd be more clever with poll of course, | |
45 | * here we are basically just blocking on output room and | |
46 | * not using the free time for anything interesting. | |
47 | */ | |
48 | if (poll(&pfd, 1, -1) < 0) | |
49 | return error("poll"); | |
50 | ||
13b72067 | 51 | written = svmsplice(fd, &iov, 1, splice_flags); |
1e404f5c | 52 | *buf = iov.iov_base; |
d07a80dc JA |
53 | |
54 | if (written < 0) | |
55 | return error("vmsplice"); | |
56 | else if (!written) | |
57 | break; | |
58 | ||
59 | len -= written; | |
60 | ret += written; | |
61 | if (len) { | |
62 | iov.iov_len -= written; | |
63 | iov.iov_base += written; | |
64 | } | |
65 | } | |
66 | ||
67 | return ret; | |
68 | } | |
69 | ||
70 | static int usage(char *name) | |
71 | { | |
ef0e4210 | 72 | fprintf(stderr, "| %s [-d(ump)] [-a(ascii)] [-m(ap)] [-z(eromap)]\n", name); |
d07a80dc JA |
73 | return 1; |
74 | } | |
75 | ||
76 | static int parse_options(int argc, char *argv[]) | |
77 | { | |
78 | int c, index = 1; | |
79 | ||
ef0e4210 | 80 | while ((c = getopt(argc, argv, "admz")) != -1) { |
d07a80dc | 81 | switch (c) { |
ef0e4210 JA |
82 | case 'a': |
83 | do_ascii = 1; | |
84 | index++; | |
85 | break; | |
d07a80dc JA |
86 | case 'd': |
87 | do_dump = 1; | |
88 | index++; | |
89 | break; | |
ef0e4210 JA |
90 | case 'm': |
91 | splice_flags |= SPLICE_F_MOVE; | |
92 | index++; | |
93 | break; | |
94 | case 'z': | |
95 | do_zeromap = 1; | |
96 | index++; | |
97 | break; | |
d07a80dc JA |
98 | default: |
99 | return -1; | |
100 | } | |
101 | } | |
102 | ||
103 | return index; | |
104 | } | |
105 | ||
106 | static void hexdump(unsigned char *buf, int len) | |
107 | { | |
108 | int i; | |
109 | ||
110 | for (i = 0; i < len; i++) | |
111 | printf("%02x", buf[i]); | |
ef0e4210 JA |
112 | } |
113 | ||
114 | static void asciidump(unsigned char *buf, int len) | |
115 | { | |
116 | int i; | |
117 | ||
118 | for (i = 0; i < len; i++) | |
119 | printf("%c", buf[i]); | |
d07a80dc JA |
120 | } |
121 | ||
122 | int main(int argc, char *argv[]) | |
123 | { | |
124 | unsigned char *buf; | |
125 | int ret; | |
126 | ||
127 | if (parse_options(argc, argv) < 0) | |
128 | return usage(argv[0]); | |
129 | ||
130 | if (check_input_pipe()) | |
131 | return usage(argv[0]); | |
132 | ||
1e404f5c JA |
133 | if (do_zeromap && !(splice_flags & SPLICE_F_MOVE)) { |
134 | fprintf(stderr, "zero map only valid for -m(ove)\n"); | |
135 | return usage(argv[0]); | |
136 | } | |
137 | ||
ef0e4210 JA |
138 | if (!do_zeromap) { |
139 | buf = malloc(4096); | |
140 | memset(buf, 0, 4096); | |
141 | } else | |
142 | buf = NULL; | |
d07a80dc | 143 | |
ef0e4210 | 144 | ret = do_vmsplice(STDIN_FILENO, &buf, 4096); |
d07a80dc JA |
145 | if (ret < 0) |
146 | return 1; | |
147 | ||
d07a80dc JA |
148 | if (do_dump) |
149 | hexdump(buf, ret); | |
ef0e4210 JA |
150 | if (do_ascii) |
151 | asciidump(buf, ret); | |
d07a80dc | 152 | |
ef0e4210 JA |
153 | if (splice_flags & SPLICE_F_MOVE) { |
154 | ret = do_vmsplice_unmap(STDIN_FILENO, buf, 4096); | |
155 | if (ret < 0) | |
156 | perror("vmsplice"); | |
157 | } | |
158 | ||
159 | return ret; | |
d07a80dc | 160 | } |