nhrpd/zbuf.h

   1 /* Stream/packet buffer API
   2  * Copyright (c) 2014-2015 Timo Teräs
   3  *
   4  * This file is free software: you may copy, redistribute and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 2 of the License, or
   7  * (at your option) any later version.
   8  */
   9
  10 #ifndef ZBUF_H
  11 #define ZBUF_H
  12
  13 #include <stdint.h>
  14 #include <string.h>
  15 #include <endian.h>
  16 #include <sys/types.h>
  17
  18 #include "zassert.h"
  19 #include "list.h"
  20
  21 struct zbuf {
  22         struct list_head queue_list;
  23         unsigned allocated : 1;
  24         unsigned error : 1;
  25         uint8_t *buf, *end;
  26         uint8_t *head, *tail;
  27 };
  28
  29 struct zbuf_queue {
  30         struct list_head queue_head;
  31 };
  32
  33 struct zbuf *zbuf_alloc(size_t size);
  34 void zbuf_init(struct zbuf *zb, void *buf, size_t len, size_t datalen);
  35 void zbuf_free(struct zbuf *zb);
  36
  37 static inline size_t zbuf_size(struct zbuf *zb)
  38 {
  39         return zb->end - zb->buf;
  40 }
  41
  42 static inline size_t zbuf_used(struct zbuf *zb)
  43 {
  44         return zb->tail - zb->head;
  45 }
  46
  47 static inline size_t zbuf_tailroom(struct zbuf *zb)
  48 {
  49         return zb->end - zb->tail;
  50 }
  51
  52 static inline size_t zbuf_headroom(struct zbuf *zb)
  53 {
  54         return zb->head - zb->buf;
  55 }
  56
  57 void zbuf_reset(struct zbuf *zb);
  58 void zbuf_reset_head(struct zbuf *zb, void *ptr);
  59 ssize_t zbuf_read(struct zbuf *zb, int fd, size_t maxlen);
  60 ssize_t zbuf_write(struct zbuf *zb, int fd);
  61 ssize_t zbuf_recv(struct zbuf *zb, int fd);
  62 ssize_t zbuf_send(struct zbuf *zb, int fd);
  63
  64 static inline void zbuf_set_rerror(struct zbuf *zb)
  65 {
  66         zb->error = 1;
  67         zb->head = zb->tail;
  68 }
  69
  70 static inline void zbuf_set_werror(struct zbuf *zb)
  71 {
  72         zb->error = 1;
  73         zb->tail = zb->end;
  74 }
  75
  76 static inline void *__zbuf_pull(struct zbuf *zb, size_t size, int error)
  77 {
  78         void *head = zb->head;
  79         if (size > zbuf_used(zb)) {
  80                 if (error) zbuf_set_rerror(zb);
  81                 return NULL;
  82         }
  83         zb->head += size;
  84         return head;
  85 }
  86
  87 #define zbuf_pull(zb, type) ((type *)__zbuf_pull(zb, sizeof(type), 1))
  88 #define zbuf_pulln(zb, sz) ((void *)__zbuf_pull(zb, sz, 1))
  89 #define zbuf_may_pull(zb, type) ((type *)__zbuf_pull(zb, sizeof(type), 0))
  90 #define zbuf_may_pulln(zb, sz) ((void *)__zbuf_pull(zb, sz, 0))
  91
  92 void *zbuf_may_pull_until(struct zbuf *zb, const char *sep, struct zbuf *msg);
  93
  94 static inline void zbuf_get(struct zbuf *zb, void *dst, size_t len)
  95 {
  96         void *src = zbuf_pulln(zb, len);
  97         if (src) memcpy(dst, src, len);
  98 }
  99
 100 static inline uint8_t zbuf_get8(struct zbuf *zb)
 101 {
 102         uint8_t *src = zbuf_pull(zb, uint8_t);
 103         if (src) return *src;
 104         return 0;
 105 }
 106
 107 static inline uint32_t zbuf_get32(struct zbuf *zb)
 108 {
 109         struct unaligned32 {
 110                 uint32_t value;
 111         } __attribute__((packed));
 112
 113         struct unaligned32 *v = zbuf_pull(zb, struct unaligned32);
 114         if (v) return v->value;
 115         return 0;
 116 }
 117
 118 static inline uint16_t zbuf_get_be16(struct zbuf *zb)
 119 {
 120         struct unaligned16 {
 121                 uint16_t value;
 122         } __attribute__((packed));
 123
 124         struct unaligned16 *v = zbuf_pull(zb, struct unaligned16);
 125         if (v) return be16toh(v->value);
 126         return 0;
 127 }
 128
 129 static inline uint32_t zbuf_get_be32(struct zbuf *zb)
 130 {
 131         return be32toh(zbuf_get32(zb));
 132 }
 133
 134 static inline void *__zbuf_push(struct zbuf *zb, size_t size, int error)
 135 {
 136         void *tail = zb->tail;
 137         if (size > zbuf_tailroom(zb)) {
 138                 if (error) zbuf_set_werror(zb);
 139                 return NULL;
 140         }
 141         zb->tail += size;
 142         return tail;
 143 }
 144
 145 #define zbuf_push(zb, type) ((type *)__zbuf_push(zb, sizeof(type), 1))
 146 #define zbuf_pushn(zb, sz) ((void *)__zbuf_push(zb, sz, 1))
 147 #define zbuf_may_push(zb, type) ((type *)__zbuf_may_push(zb, sizeof(type), 0))
 148 #define zbuf_may_pushn(zb, sz) ((void *)__zbuf_push(zb, sz, 0))
 149
 150 static inline void zbuf_put(struct zbuf *zb, const void *src, size_t len)
 151 {
 152         void *dst = zbuf_pushn(zb, len);
 153         if (dst) memcpy(dst, src, len);
 154 }
 155
 156 static inline void zbuf_put8(struct zbuf *zb, uint8_t val)
 157 {
 158         uint8_t *dst = zbuf_push(zb, uint8_t);
 159         if (dst) *dst = val;
 160 }
 161
 162 static inline void zbuf_put_be16(struct zbuf *zb, uint16_t val)
 163 {
 164         struct unaligned16 {
 165                 uint16_t value;
 166         } __attribute__((packed));
 167
 168         struct unaligned16 *v = zbuf_push(zb, struct unaligned16);
 169         if (v) v->value = htobe16(val);
 170 }
 171
 172 static inline void zbuf_put_be32(struct zbuf *zb, uint32_t val)
 173 {
 174         struct unaligned32 {
 175                 uint32_t value;
 176         } __attribute__((packed));
 177
 178         struct unaligned32 *v = zbuf_push(zb, struct unaligned32);
 179         if (v) v->value = htobe32(val);
 180 }
 181
 182 void zbuf_copy(struct zbuf *zb, struct zbuf *src, size_t len);
 183
 184 void zbufq_init(struct zbuf_queue *);
 185 void zbufq_reset(struct zbuf_queue *);
 186 void zbufq_queue(struct zbuf_queue *, struct zbuf *);
 187 int zbufq_write(struct zbuf_queue *, int);
 188
 189 #endif