1 /*
2 * ustream - library for stream buffer management
3 *
4 * Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
5 *
6 * Permission to use, copy, modify, and/or distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19 #include <unistd.h>
20 #include <errno.h>
21 #include <stdio.h>
22 #include "ustream.h"
23
ustream_fd_set_uloop(struct ustream * s,bool write)24 static void ustream_fd_set_uloop(struct ustream *s, bool write)
25 {
26 struct ustream_fd *sf = container_of(s, struct ustream_fd, stream);
27 struct ustream_buf *buf;
28 unsigned int flags = ULOOP_EDGE_TRIGGER | ULOOP_ERROR_CB;
29
30 if (!s->read_blocked && !s->eof)
31 flags |= ULOOP_READ;
32
33 buf = s->w.head;
34 if (write || (buf && s->w.data_bytes && !s->write_error))
35 flags |= ULOOP_WRITE;
36
37 uloop_fd_add(&sf->fd, flags);
38 }
39
ustream_fd_set_read_blocked(struct ustream * s)40 static void ustream_fd_set_read_blocked(struct ustream *s)
41 {
42 ustream_fd_set_uloop(s, false);
43 }
44
ustream_fd_read_pending(struct ustream_fd * sf,bool * more)45 static void ustream_fd_read_pending(struct ustream_fd *sf, bool *more)
46 {
47 struct ustream *s = &sf->stream;
48 int buflen = 0;
49 ssize_t len;
50 char *buf;
51
52 do {
53 if (s->read_blocked)
54 break;
55
56 buf = ustream_reserve(s, 1, &buflen);
57 if (!buf)
58 break;
59
60 len = read(sf->fd.fd, buf, buflen);
61 if (len < 0) {
62 if (errno == EINTR)
63 continue;
64
65 if (errno == EAGAIN || errno == ENOTCONN)
66 return;
67
68 len = 0;
69 }
70
71 if (!len) {
72 if (!s->eof)
73 ustream_state_change(s);
74 s->eof = true;
75 ustream_fd_set_uloop(s, false);
76 return;
77 }
78
79 ustream_fill_read(s, len);
80 *more = true;
81 } while (1);
82 }
83
ustream_fd_write(struct ustream * s,const char * buf,int buflen,bool more)84 static int ustream_fd_write(struct ustream *s, const char *buf, int buflen, bool more)
85 {
86 struct ustream_fd *sf = container_of(s, struct ustream_fd, stream);
87 ssize_t ret = 0, len;
88
89 if (!buflen)
90 return 0;
91
92 while (buflen) {
93 len = write(sf->fd.fd, buf, buflen);
94
95 if (len < 0) {
96 if (errno == EINTR)
97 continue;
98
99 if (errno == EAGAIN || errno == EWOULDBLOCK || errno == ENOTCONN)
100 break;
101
102 return -1;
103 }
104
105 ret += len;
106 buf += len;
107 buflen -= len;
108 }
109
110 if (buflen)
111 ustream_fd_set_uloop(s, true);
112
113 return ret;
114 }
115
__ustream_fd_poll(struct ustream_fd * sf,unsigned int events)116 static bool __ustream_fd_poll(struct ustream_fd *sf, unsigned int events)
117 {
118 struct ustream *s = &sf->stream;
119 bool more = false;
120
121 if (events & ULOOP_READ)
122 ustream_fd_read_pending(sf, &more);
123
124 if (events & ULOOP_WRITE) {
125 bool no_more = ustream_write_pending(s);
126 if (no_more)
127 ustream_fd_set_uloop(s, false);
128 }
129
130 if (sf->fd.error && !s->write_error) {
131 ustream_state_change(s);
132 s->write_error = true;
133 ustream_fd_set_uloop(s, false);
134 }
135
136 return more;
137 }
138
ustream_fd_poll(struct ustream * s)139 static bool ustream_fd_poll(struct ustream *s)
140 {
141 struct ustream_fd *sf = container_of(s, struct ustream_fd, stream);
142
143 return __ustream_fd_poll(sf, ULOOP_READ | ULOOP_WRITE);
144 }
145
ustream_uloop_cb(struct uloop_fd * fd,unsigned int events)146 static void ustream_uloop_cb(struct uloop_fd *fd, unsigned int events)
147 {
148 struct ustream_fd *sf = container_of(fd, struct ustream_fd, fd);
149
150 __ustream_fd_poll(sf, events);
151 }
152
ustream_fd_free(struct ustream * s)153 static void ustream_fd_free(struct ustream *s)
154 {
155 struct ustream_fd *sf = container_of(s, struct ustream_fd, stream);
156
157 uloop_fd_delete(&sf->fd);
158 }
159
ustream_fd_init(struct ustream_fd * sf,int fd)160 void ustream_fd_init(struct ustream_fd *sf, int fd)
161 {
162 struct ustream *s = &sf->stream;
163
164 ustream_init_defaults(s);
165
166 sf->fd.fd = fd;
167 sf->fd.cb = ustream_uloop_cb;
168 s->set_read_blocked = ustream_fd_set_read_blocked;
169 s->write = ustream_fd_write;
170 s->free = ustream_fd_free;
171 s->poll = ustream_fd_poll;
172 ustream_fd_set_uloop(s, false);
173 }
174