buffer.c 4.8 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205
#include "tunala.h"

#ifndef NO_BUFFER

void buffer_init(buffer_t *buf)
{
	buf->used = 0;
	buf->total_in = buf->total_out = 0;
}

void buffer_close(buffer_t *buf)
{
	/* Our data is static - nothing needs "release", just reset it */
	buf->used = 0;
}

/* Code these simple ones in compact form */
unsigned int buffer_used(buffer_t *buf) {
	return buf->used; }
unsigned int buffer_unused(buffer_t *buf) {
	return (MAX_DATA_SIZE - buf->used); }
int buffer_full(buffer_t *buf) {
	return (buf->used == MAX_DATA_SIZE ? 1 : 0); }
int buffer_notfull(buffer_t *buf) {
	return (buf->used < MAX_DATA_SIZE ? 1 : 0); }
int buffer_empty(buffer_t *buf) {
	return (buf->used == 0 ? 1 : 0); }
int buffer_notempty(buffer_t *buf) {
	return (buf->used > 0 ? 1 : 0); }
unsigned long buffer_total_in(buffer_t *buf) {
	return buf->total_in; }
unsigned long buffer_total_out(buffer_t *buf) {
	return buf->total_out; }

/* These 3 static (internal) functions don't adjust the "total" variables as
 * it's not sure when they're called how it should be interpreted. Only the
 * higher-level "buffer_[to|from]_[fd|SSL|BIO]" functions should alter these
 * values. */
#if 0 /* To avoid "unused" warnings */
static unsigned int buffer_adddata(buffer_t *buf, const unsigned char *ptr,
		unsigned int size)
{
	unsigned int added = MAX_DATA_SIZE - buf->used;
	if(added > size)
		added = size;
	if(added == 0)
		return 0;
	memcpy(buf->data + buf->used, ptr, added);
	buf->used += added;
	buf->total_in += added;
	return added;
}

static unsigned int buffer_tobuffer(buffer_t *to, buffer_t *from, int cap)
{
	unsigned int moved, tomove = from->used;
	if((int)tomove > cap)
		tomove = cap;
	if(tomove == 0)
		return 0;
	moved = buffer_adddata(to, from->data, tomove);
	if(moved == 0)
		return 0;
	buffer_takedata(from, NULL, moved);
	return moved;
}
#endif

static unsigned int buffer_takedata(buffer_t *buf, unsigned char *ptr,
		unsigned int size)
{
	unsigned int taken = buf->used;
	if(taken > size)
		taken = size;
	if(taken == 0)
		return 0;
	if(ptr)
		memcpy(ptr, buf->data, taken);
	buf->used -= taken;
	/* Do we have to scroll? */
	if(buf->used > 0)
		memmove(buf->data, buf->data + taken, buf->used);
	return taken;
}

#ifndef NO_IP

int buffer_from_fd(buffer_t *buf, int fd)
{
	int toread = buffer_unused(buf);
	if(toread == 0)
		/* Shouldn't be called in this case! */
		abort();
	toread = read(fd, buf->data + buf->used, toread);
	if(toread > 0) {
		buf->used += toread;
		buf->total_in += toread;
	}
	return toread;
}

int buffer_to_fd(buffer_t *buf, int fd)
{
	int towrite = buffer_used(buf);
	if(towrite == 0)
		/* Shouldn't be called in this case! */
		abort();
	towrite = write(fd, buf->data, towrite);
	if(towrite > 0) {
		buffer_takedata(buf, NULL, towrite);
		buf->total_out += towrite;
	}
	return towrite;
}

#endif /* !defined(NO_IP) */

#ifndef NO_OPENSSL

static void int_ssl_check(SSL *s, int ret)
{
	int e = SSL_get_error(s, ret);
	switch(e) {
		/* These seem to be harmless and already "dealt with" by our
		 * non-blocking environment. NB: "ZERO_RETURN" is the clean
		 * "error" indicating a successfully closed SSL tunnel. We let
		 * this happen because our IO loop should not appear to have
		 * broken on this condition - and outside the IO loop, the
		 * "shutdown" state is checked. */
	case SSL_ERROR_NONE:
	case SSL_ERROR_WANT_READ:
	case SSL_ERROR_WANT_WRITE:
	case SSL_ERROR_WANT_X509_LOOKUP:
	case SSL_ERROR_ZERO_RETURN:
		return;
		/* These seem to be indications of a genuine error that should
		 * result in the SSL tunnel being regarded as "dead". */
	case SSL_ERROR_SYSCALL:
	case SSL_ERROR_SSL:
		SSL_set_app_data(s, (char *)1);
		return;
	default:
		break;
	}
	/* For any other errors that (a) exist, and (b) crop up - we need to
	 * interpret what to do with them - so "politely inform" the caller that
	 * the code needs updating here. */
	abort();
}

void buffer_from_SSL(buffer_t *buf, SSL *ssl)
{
	int ret;
	if(!ssl || buffer_full(buf))
		return;
	ret = SSL_read(ssl, buf->data + buf->used, buffer_unused(buf));
	if(ret > 0) {
		buf->used += ret;
		buf->total_in += ret;
	}
	if(ret < 0)
		int_ssl_check(ssl, ret);
}

void buffer_to_SSL(buffer_t *buf, SSL *ssl)
{
	int ret;
	if(!ssl || buffer_empty(buf))
		return;
	ret = SSL_write(ssl, buf->data, buf->used);
	if(ret > 0) {
		buffer_takedata(buf, NULL, ret);
		buf->total_out += ret;
	}
	if(ret < 0)
		int_ssl_check(ssl, ret);
}

void buffer_from_BIO(buffer_t *buf, BIO *bio)
{
	int ret;
	if(!bio || buffer_full(buf))
		return;
	ret = BIO_read(bio, buf->data + buf->used, buffer_unused(buf));
	if(ret > 0) {
		buf->used += ret;
		buf->total_in += ret;
	}
}

void buffer_to_BIO(buffer_t *buf, BIO *bio)
{
	int ret;
	if(!bio || buffer_empty(buf))
		return;
	ret = BIO_write(bio, buf->data, buf->used);
	if(ret > 0) {
		buffer_takedata(buf, NULL, ret);
		buf->total_out += ret;
	}
}

#endif /* !defined(NO_OPENSSL) */

#endif /* !defined(NO_BUFFER) */