diff options
Diffstat (limited to 'nhrpd/zbuf.c')
| -rw-r--r-- | nhrpd/zbuf.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/nhrpd/zbuf.c b/nhrpd/zbuf.c new file mode 100644 index 00000000..ead7cfd2 --- /dev/null +++ b/nhrpd/zbuf.c @@ -0,0 +1,219 @@ +/* Stream/packet buffer API implementation + * Copyright (c) 2014-2015 Timo Teräs + * + * This file is free software: you may copy, redistribute and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 2 of the License, or + * (at your option) any later version. + */ + +#define _GNU_SOURCE +#include <string.h> +#include <unistd.h> +#include <errno.h> +#include "zassert.h" +#include "zbuf.h" +#include "memory.h" +#include "memtypes.h" +#include "nhrpd.h" + +#define ERRNO_IO_RETRY(EN) (((EN) == EAGAIN) || ((EN) == EWOULDBLOCK) || ((EN) == EINTR)) + +struct zbuf *zbuf_alloc(size_t size) +{ + struct zbuf *zb; + + zb = XMALLOC(MTYPE_STREAM_DATA, sizeof(*zb) + size); + if (!zb) + return NULL; + + zbuf_init(zb, zb+1, size, 0); + zb->allocated = 1; + + return zb; +} + +void zbuf_init(struct zbuf *zb, void *buf, size_t len, size_t datalen) +{ + *zb = (struct zbuf) { + .buf = buf, + .end = (uint8_t *)buf + len, + .head = buf, + .tail = (uint8_t *)buf + datalen, + }; +} + +void zbuf_free(struct zbuf *zb) +{ + if (zb->allocated) + XFREE(MTYPE_STREAM_DATA, zb); +} + +void zbuf_reset(struct zbuf *zb) +{ + zb->head = zb->tail = zb->buf; + zb->error = 0; +} + +void zbuf_reset_head(struct zbuf *zb, void *ptr) +{ + zassert((void*)zb->buf <= ptr && ptr <= (void*)zb->tail); + zb->head = ptr; +} + +static void zbuf_remove_headroom(struct zbuf *zb) +{ + ssize_t headroom = zbuf_headroom(zb); + if (!headroom) + return; + memmove(zb->buf, zb->head, zbuf_used(zb)); + zb->head -= headroom; + zb->tail -= headroom; +} + +ssize_t zbuf_read(struct zbuf *zb, int fd, size_t maxlen) +{ + ssize_t r; + + if (zb->error) + return -3; + + zbuf_remove_headroom(zb); + if (maxlen > zbuf_tailroom(zb)) + maxlen = zbuf_tailroom(zb); + + r = read(fd, zb->tail, maxlen); + if (r > 0) zb->tail += r; + else if (r == 0) r = -2; + else if (r < 0 && ERRNO_IO_RETRY(errno)) r = 0; + + return r; +} + +ssize_t zbuf_write(struct zbuf *zb, int fd) +{ + ssize_t r; + + if (zb->error) + return -3; + + r = write(fd, zb->head, zbuf_used(zb)); + if (r > 0) { + zb->head += r; + if (zb->head == zb->tail) + zbuf_reset(zb); + } + else if (r == 0) r = -2; + else if (r < 0 && ERRNO_IO_RETRY(errno)) r = 0; + + return r; +} + +ssize_t zbuf_recv(struct zbuf *zb, int fd) +{ + ssize_t r; + + if (zb->error) + return -3; + + zbuf_remove_headroom(zb); + r = recv(fd, zb->tail, zbuf_tailroom(zb), 0); + if (r > 0) zb->tail += r; + else if (r == 0) r = -2; + else if (r < 0 && ERRNO_IO_RETRY(errno)) r = 0; + return r; +} + +ssize_t zbuf_send(struct zbuf *zb, int fd) +{ + ssize_t r; + + if (zb->error) + return -3; + + r = send(fd, zb->head, zbuf_used(zb), 0); + if (r >= 0) + zbuf_reset(zb); + + return r; +} + +void *zbuf_may_pull_until(struct zbuf *zb, const char *sep, struct zbuf *msg) +{ + size_t seplen = strlen(sep), len; + uint8_t *ptr; + + ptr = memmem(zb->head, zbuf_used(zb), sep, seplen); + if (!ptr) return NULL; + + len = ptr - zb->head + seplen; + zbuf_init(msg, zbuf_pulln(zb, len), len, len); + return msg->head; +} + +void zbufq_init(struct zbuf_queue *zbq) +{ + *zbq = (struct zbuf_queue) { + .queue_head = LIST_INITIALIZER(zbq->queue_head), + }; +} + +void zbufq_reset(struct zbuf_queue *zbq) +{ + struct zbuf *buf, *bufn; + + list_for_each_entry_safe(buf, bufn, &zbq->queue_head, queue_list) { + list_del(&buf->queue_list); + zbuf_free(buf); + } +} + +void zbufq_queue(struct zbuf_queue *zbq, struct zbuf *zb) +{ + list_add_tail(&zb->queue_list, &zbq->queue_head); +} + +int zbufq_write(struct zbuf_queue *zbq, int fd) +{ + struct iovec iov[16]; + struct zbuf *zb, *zbn; + ssize_t r; + size_t iovcnt = 0; + + list_for_each_entry_safe(zb, zbn, &zbq->queue_head, queue_list) { + iov[iovcnt++] = (struct iovec) { + .iov_base = zb->head, + .iov_len = zbuf_used(zb), + }; + if (iovcnt >= ZEBRA_NUM_OF(iov)) + break; + } + + r = writev(fd, iov, iovcnt); + if (r < 0) + return r; + + list_for_each_entry_safe(zb, zbn, &zbq->queue_head, queue_list) { + if (r < (ssize_t)zbuf_used(zb)) { + zb->head += r; + return 1; + } + + r -= zbuf_used(zb); + list_del(&zb->queue_list); + zbuf_free(zb); + } + + return 0; +} + +void zbuf_copy(struct zbuf *zdst, struct zbuf *zsrc, size_t len) +{ + const void *src; + void *dst; + + dst = zbuf_pushn(zdst, len); + src = zbuf_pulln(zsrc, len); + if (!dst || !src) return; + memcpy(dst, src, len); +} |