1 /*
2 * libwebsockets - small server side websockets and web server implementation
3 *
4 * Copyright (C) 2010 - 2019 Andy Green <andy@warmcat.com>
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to
8 * deal in the Software without restriction, including without limitation the
9 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
10 * sell copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
22 * IN THE SOFTWARE.
23 */
24
25 #include "private-lib-core.h"
26
27 #ifdef LWS_HAVE_SYS_TYPES_H
28 #include <sys/types.h>
29 #endif
30
31 /* lws_buflist */
32
33 int
lws_buflist_append_segment(struct lws_buflist ** head,const uint8_t * buf,size_t len)34 lws_buflist_append_segment(struct lws_buflist **head, const uint8_t *buf,
35 size_t len)
36 {
37 struct lws_buflist *nbuf;
38 int first = !*head;
39 void *p = *head;
40 int sanity = 1024;
41
42 assert(buf);
43 assert(len);
44
45 /* append at the tail */
46 while (*head) {
47 if (!--sanity) {
48 lwsl_err("%s: buflist reached sanity limit\n", __func__);
49 return -1;
50 }
51 if (*head == (*head)->next) {
52 lwsl_err("%s: corrupt list points to self\n", __func__);
53 return -1;
54 }
55 head = &((*head)->next);
56 }
57
58 (void)p;
59 lwsl_info("%s: len %u first %d %p\n", __func__, (unsigned int)len,
60 first, p);
61
62 nbuf = (struct lws_buflist *)lws_malloc(sizeof(struct lws_buflist) +
63 len + LWS_PRE + 1, __func__);
64 if (!nbuf) {
65 lwsl_err("%s: OOM\n", __func__);
66 return -1;
67 }
68
69 nbuf->len = len;
70 nbuf->pos = 0;
71 nbuf->next = NULL;
72
73 /* whoever consumes this might need LWS_PRE from the start... */
74 p = (uint8_t *)nbuf + sizeof(*nbuf) + LWS_PRE;
75 memcpy(p, buf, len);
76
77 *head = nbuf;
78
79 return first; /* returns 1 if first segment just created */
80 }
81
82 static int
lws_buflist_destroy_segment(struct lws_buflist ** head)83 lws_buflist_destroy_segment(struct lws_buflist **head)
84 {
85 struct lws_buflist *old = *head;
86
87 assert(*head);
88 *head = old->next;
89 old->next = NULL;
90 old->pos = old->len = 0;
91 lws_free(old);
92
93 return !*head; /* returns 1 if last segment just destroyed */
94 }
95
96 void
lws_buflist_destroy_all_segments(struct lws_buflist ** head)97 lws_buflist_destroy_all_segments(struct lws_buflist **head)
98 {
99 struct lws_buflist *p = *head, *p1;
100
101 while (p) {
102 p1 = p->next;
103 p->next = NULL;
104 lws_free(p);
105 p = p1;
106 }
107
108 *head = NULL;
109 }
110
111 size_t
lws_buflist_next_segment_len(struct lws_buflist ** head,uint8_t ** buf)112 lws_buflist_next_segment_len(struct lws_buflist **head, uint8_t **buf)
113 {
114 struct lws_buflist *b = (*head);
115
116 if (buf)
117 *buf = NULL;
118
119 if (!b)
120 return 0; /* there is no next segment len */
121
122 if (!b->len && b->next)
123 if (lws_buflist_destroy_segment(head))
124 return 0;
125
126 b = (*head);
127 if (!b)
128 return 0; /* there is no next segment len */
129
130 assert(b->pos < b->len);
131
132 if (buf)
133 *buf = ((uint8_t *)b) + sizeof(*b) + b->pos + LWS_PRE;
134
135 return b->len - b->pos;
136 }
137
138 size_t
lws_buflist_use_segment(struct lws_buflist ** head,size_t len)139 lws_buflist_use_segment(struct lws_buflist **head, size_t len)
140 {
141 struct lws_buflist *b = (*head);
142
143 assert(b);
144 assert(len);
145 assert(b->pos + len <= b->len);
146
147 b->pos = b->pos + (size_t)len;
148
149 assert(b->pos <= b->len);
150
151 if (b->pos < b->len)
152 return (unsigned int)(b->len - b->pos);
153
154 if (lws_buflist_destroy_segment(head))
155 /* last segment was just destroyed */
156 return 0;
157
158 return lws_buflist_next_segment_len(head, NULL);
159 }
160
161 size_t
lws_buflist_total_len(struct lws_buflist ** head)162 lws_buflist_total_len(struct lws_buflist **head)
163 {
164 struct lws_buflist *p = *head;
165 size_t size = 0;
166
167 while (p) {
168 size += p->len;
169 p = p->next;
170 }
171
172 return size;
173 }
174
175 int
lws_buflist_linear_copy(struct lws_buflist ** head,size_t ofs,uint8_t * buf,size_t len)176 lws_buflist_linear_copy(struct lws_buflist **head, size_t ofs, uint8_t *buf,
177 size_t len)
178 {
179 struct lws_buflist *p = *head;
180 uint8_t *obuf = buf;
181 size_t s;
182
183 while (p && len) {
184 if (ofs < p->len) {
185 s = p->len - ofs;
186 if (s > len)
187 s = len;
188 memcpy(buf, ((uint8_t *)&p[1]) + LWS_PRE + ofs, s);
189 len -= s;
190 buf += s;
191 ofs = 0;
192 } else
193 ofs -= p->len;
194 p = p->next;
195 }
196
197 return lws_ptr_diff(buf, obuf);
198 }
199
200 int
lws_buflist_linear_use(struct lws_buflist ** head,uint8_t * buf,size_t len)201 lws_buflist_linear_use(struct lws_buflist **head, uint8_t *buf, size_t len)
202 {
203 uint8_t *obuf = buf;
204 size_t s;
205
206 while (*head && len) {
207 s = (*head)->len - (*head)->pos;
208 if (s > len)
209 s = len;
210 memcpy(buf, ((uint8_t *)((*head) + 1)) +
211 LWS_PRE + (*head)->pos, s);
212 len -= s;
213 buf += s;
214 lws_buflist_use_segment(head, s);
215 }
216
217 return lws_ptr_diff(buf, obuf);
218 }
219
220 int
lws_buflist_fragment_use(struct lws_buflist ** head,uint8_t * buf,size_t len,char * frag_first,char * frag_fin)221 lws_buflist_fragment_use(struct lws_buflist **head, uint8_t *buf,
222 size_t len, char *frag_first, char *frag_fin)
223 {
224 uint8_t *obuf = buf;
225 size_t s;
226
227 if (!*head)
228 return 0;
229
230 s = (*head)->len - (*head)->pos;
231 if (s > len)
232 s = len;
233
234 if (frag_first)
235 *frag_first = !(*head)->pos;
236
237 if (frag_fin)
238 *frag_fin = (*head)->pos + s == (*head)->len;
239
240 memcpy(buf, ((uint8_t *)((*head) + 1)) + LWS_PRE + (*head)->pos, s);
241 len -= s;
242 buf += s;
243 lws_buflist_use_segment(head, s);
244
245 return lws_ptr_diff(buf, obuf);
246 }
247
248 #if defined(_DEBUG)
249 void
lws_buflist_describe(struct lws_buflist ** head,void * id,const char * reason)250 lws_buflist_describe(struct lws_buflist **head, void *id, const char *reason)
251 {
252 struct lws_buflist *old;
253 int n = 0;
254
255 if (*head == NULL)
256 lwsl_notice("%p: %s: buflist empty\n", id, reason);
257
258 while (*head) {
259 lwsl_notice("%p: %s: %d: %llu / %llu (%llu left)\n", id,
260 reason, n,
261 (unsigned long long)(*head)->pos,
262 (unsigned long long)(*head)->len,
263 (unsigned long long)(*head)->len - (*head)->pos);
264 old = *head;
265 head = &((*head)->next);
266 if (*head == old) {
267 lwsl_err("%s: next points to self\n", __func__);
268 break;
269 }
270 n++;
271 }
272 }
273 #endif
274