X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lib%2Fofpbuf.c;h=91ea36303f9f2d06be06d412f730f3d14eb1a4c4;hb=ec842d37d5702357d04044d1d2c1b7b09852d63e;hp=bb216791b59fad3853e32a05dc9592b316994f74;hpb=c69ee87c10818267f991236201150b1fa51ae519;p=sliver-openvswitch.git diff --git a/lib/ofpbuf.c b/lib/ofpbuf.c index bb216791b..91ea36303 100644 --- a/lib/ofpbuf.c +++ b/lib/ofpbuf.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2008, 2009 Nicira Networks. + * Copyright (c) 2008, 2009, 2010 Nicira Networks. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. @@ -19,6 +19,7 @@ #include #include #include +#include "dynamic-string.h" #include "util.h" /* Initializes 'b' as an empty ofpbuf that contains the 'allocated' bytes of @@ -35,10 +36,21 @@ ofpbuf_use(struct ofpbuf *b, void *base, size_t allocated) b->allocated = allocated; b->size = 0; b->l2 = b->l3 = b->l4 = b->l7 = NULL; - b->next = NULL; + list_poison(&b->list_node); b->private_p = NULL; } +/* Initializes 'b' as an ofpbuf whose data starts at 'data' and continues for + * 'size' bytes. This is appropriate for an ofpbuf that will be used to + * inspect existing data, without moving it around or reallocating it, and + * generally without modifying it at all. */ +void +ofpbuf_use_const(struct ofpbuf *b, const void *data, size_t size) +{ + ofpbuf_use(b, (void *) data, size); + b->size = size; +} + /* Initializes 'b' as an empty ofpbuf with an initial capacity of 'size' * bytes. */ void @@ -49,7 +61,7 @@ ofpbuf_init(struct ofpbuf *b, size_t size) /* Frees memory that 'b' points to. */ void -ofpbuf_uninit(struct ofpbuf *b) +ofpbuf_uninit(struct ofpbuf *b) { if (b) { free(b->base); @@ -74,12 +86,32 @@ ofpbuf_new(size_t size) return b; } +/* Creates and returns a new ofpbuf with an initial capacity of 'size + + * headroom' bytes, reserving the first 'headroom' bytes as headroom. */ +struct ofpbuf * +ofpbuf_new_with_headroom(size_t size, size_t headroom) +{ + struct ofpbuf *b = ofpbuf_new(size + headroom); + ofpbuf_reserve(b, headroom); + return b; +} + struct ofpbuf * ofpbuf_clone(const struct ofpbuf *buffer) { return ofpbuf_clone_data(buffer->data, buffer->size); } +/* Creates and returns a new ofpbuf whose data are copied from 'buffer'. The + * returned ofpbuf will additionally have 'headroom' bytes of headroom. */ +struct ofpbuf * +ofpbuf_clone_with_headroom(const struct ofpbuf *buffer, size_t headroom) +{ + struct ofpbuf *b = ofpbuf_new_with_headroom(buffer->size, headroom); + ofpbuf_put(b, buffer->data, buffer->size); + return b; +} + struct ofpbuf * ofpbuf_clone_data(const void *data, size_t size) { @@ -90,7 +122,7 @@ ofpbuf_clone_data(const void *data, size_t size) /* Frees memory that 'b' points to, as well as 'b' itself. */ void -ofpbuf_delete(struct ofpbuf *b) +ofpbuf_delete(struct ofpbuf *b) { if (b) { ofpbuf_uninit(b); @@ -103,7 +135,7 @@ ofpbuf_delete(struct ofpbuf *b) * commonly, the data in a ofpbuf is at its beginning, and thus the ofpbuf's * headroom is 0.) */ size_t -ofpbuf_headroom(struct ofpbuf *b) +ofpbuf_headroom(const struct ofpbuf *b) { return (char*)b->data - (char*)b->base; } @@ -111,24 +143,19 @@ ofpbuf_headroom(struct ofpbuf *b) /* Returns the number of bytes that may be appended to the tail end of ofpbuf * 'b' before the ofpbuf must be reallocated. */ size_t -ofpbuf_tailroom(struct ofpbuf *b) +ofpbuf_tailroom(const struct ofpbuf *b) { return (char*)ofpbuf_end(b) - (char*)ofpbuf_tail(b); } -/* Ensures that 'b' has room for at least 'size' bytes at its tail end, - * reallocating and copying its data if necessary. */ -void -ofpbuf_prealloc_tailroom(struct ofpbuf *b, size_t size) +/* Changes 'b->base' to 'new_base' and adjusts all of 'b''s internal pointers + * to reflect the change. */ +static void +ofpbuf_rebase__(struct ofpbuf *b, void *new_base) { - if (size > ofpbuf_tailroom(b)) { - size_t new_allocated = b->allocated + MAX(size, 64); - void *new_base = xmalloc(new_allocated); + if (b->base != new_base) { uintptr_t base_delta = (char*)new_base - (char*)b->base; - memcpy(new_base, b->base, b->allocated); - free(b->base); b->base = new_base; - b->allocated = new_allocated; b->data = (char*)b->data + base_delta; if (b->l2) { b->l2 = (char*)b->l2 + base_delta; @@ -145,22 +172,38 @@ ofpbuf_prealloc_tailroom(struct ofpbuf *b, size_t size) } } +/* Reallocates 'b' so that it has exactly 'new_tailroom' bytes of tailroom. */ +static void +ofpbuf_resize_tailroom__(struct ofpbuf *b, size_t new_tailroom) +{ + b->allocated = ofpbuf_headroom(b) + b->size + new_tailroom; + ofpbuf_rebase__(b, xrealloc(b->base, b->allocated)); +} + +/* Ensures that 'b' has room for at least 'size' bytes at its tail end, + * reallocating and copying its data if necessary. Its headroom, if any, is + * preserved. */ +void +ofpbuf_prealloc_tailroom(struct ofpbuf *b, size_t size) +{ + if (size > ofpbuf_tailroom(b)) { + ofpbuf_resize_tailroom__(b, MAX(size, 64)); + } +} + void -ofpbuf_prealloc_headroom(struct ofpbuf *b, size_t size) +ofpbuf_prealloc_headroom(struct ofpbuf *b, size_t size) { assert(size <= ofpbuf_headroom(b)); } -/* Trims the size of 'b' to fit its actual content. */ +/* Trims the size of 'b' to fit its actual content, reducing its tailroom to + * 0. Its headroom, if any, is preserved. */ void ofpbuf_trim(struct ofpbuf *b) { - /* XXX These could be supported, but the current client doesn't care. */ - assert(b->data == b->base); - assert(b->l2 == NULL && b->l3 == NULL && b->l4 == NULL && b->l7 == NULL); - if (b->allocated > b->size) { - b->base = b->data = xrealloc(b->base, b->size); - b->allocated = b->size; + if (ofpbuf_tailroom(b) > 0) { + ofpbuf_resize_tailroom__(b, 0); } } @@ -168,7 +211,7 @@ ofpbuf_trim(struct ofpbuf *b) * copying its data if necessary. Returns a pointer to the first byte of the * new data, which is left uninitialized. */ void * -ofpbuf_put_uninit(struct ofpbuf *b, size_t size) +ofpbuf_put_uninit(struct ofpbuf *b, size_t size) { void *p; ofpbuf_prealloc_tailroom(b, size); @@ -192,17 +235,44 @@ ofpbuf_put_zeros(struct ofpbuf *b, size_t size) * is reallocated and copied if necessary. Returns a pointer to the first * byte of the data's location in the ofpbuf. */ void * -ofpbuf_put(struct ofpbuf *b, const void *p, size_t size) +ofpbuf_put(struct ofpbuf *b, const void *p, size_t size) { void *dst = ofpbuf_put_uninit(b, size); memcpy(dst, p, size); return dst; } +/* Parses as many pairs of hex digits as possible (possibly separated by + * spaces) from the beginning of 's', appending bytes for their values to 'b'. + * Returns the first character of 's' that is not the first of a pair of hex + * digits. If 'n' is nonnull, stores the number of bytes added to 'b' in + * '*n'. */ +char * +ofpbuf_put_hex(struct ofpbuf *b, const char *s, size_t *n) +{ + size_t initial_size = b->size; + for (;;) { + uint8_t byte; + bool ok; + + s += strspn(s, " "); + byte = hexits_value(s, 2, &ok); + if (!ok) { + if (n) { + *n = b->size - initial_size; + } + return (char *) s; + } + + ofpbuf_put(b, &byte, 1); + s += 2; + } +} + /* Reserves 'size' bytes of headroom so that they can be later allocated with * ofpbuf_push_uninit() without reallocating the ofpbuf. */ void -ofpbuf_reserve(struct ofpbuf *b, size_t size) +ofpbuf_reserve(struct ofpbuf *b, size_t size) { assert(!b->size); ofpbuf_prealloc_tailroom(b, size); @@ -210,7 +280,7 @@ ofpbuf_reserve(struct ofpbuf *b, size_t size) } void * -ofpbuf_push_uninit(struct ofpbuf *b, size_t size) +ofpbuf_push_uninit(struct ofpbuf *b, size_t size) { ofpbuf_prealloc_headroom(b, size); b->data = (char*)b->data - size; @@ -218,8 +288,19 @@ ofpbuf_push_uninit(struct ofpbuf *b, size_t size) return b->data; } +/* Prefixes 'size' zeroed bytes to the head end of 'b'. 'b' must have at least + * 'size' bytes of headroom. Returns a pointer to the first byte of the data's + * location in the ofpbuf. */ +void * +ofpbuf_push_zeros(struct ofpbuf *b, size_t size) +{ + void *dst = ofpbuf_push_uninit(b, size); + memset(dst, 0, size); + return dst; +} + void * -ofpbuf_push(struct ofpbuf *b, const void *p, size_t size) +ofpbuf_push(struct ofpbuf *b, const void *p, size_t size) { void *dst = ofpbuf_push_uninit(b, size); memcpy(dst, p, size); @@ -229,7 +310,7 @@ ofpbuf_push(struct ofpbuf *b, const void *p, size_t size) /* If 'b' contains at least 'offset + size' bytes of data, returns a pointer to * byte 'offset'. Otherwise, returns a null pointer. */ void * -ofpbuf_at(const struct ofpbuf *b, size_t offset, size_t size) +ofpbuf_at(const struct ofpbuf *b, size_t offset, size_t size) { return offset + size <= b->size ? (char *) b->data + offset : NULL; } @@ -237,7 +318,7 @@ ofpbuf_at(const struct ofpbuf *b, size_t offset, size_t size) /* Returns a pointer to byte 'offset' in 'b', which must contain at least * 'offset + size' bytes of data. */ void * -ofpbuf_at_assert(const struct ofpbuf *b, size_t offset, size_t size) +ofpbuf_at_assert(const struct ofpbuf *b, size_t offset, size_t size) { assert(offset + size <= b->size); return ((char *) b->data) + offset; @@ -245,7 +326,7 @@ ofpbuf_at_assert(const struct ofpbuf *b, size_t offset, size_t size) /* Returns the byte following the last byte of data in use in 'b'. */ void * -ofpbuf_tail(const struct ofpbuf *b) +ofpbuf_tail(const struct ofpbuf *b) { return (char *) b->data + b->size; } @@ -253,14 +334,14 @@ ofpbuf_tail(const struct ofpbuf *b) /* Returns the byte following the last byte allocated for use (but not * necessarily in use) by 'b'. */ void * -ofpbuf_end(const struct ofpbuf *b) +ofpbuf_end(const struct ofpbuf *b) { return (char *) b->base + b->allocated; } /* Clears any data from 'b'. */ void -ofpbuf_clear(struct ofpbuf *b) +ofpbuf_clear(struct ofpbuf *b) { b->data = b->base; b->size = 0; @@ -269,7 +350,7 @@ ofpbuf_clear(struct ofpbuf *b) /* Removes 'size' bytes from the head end of 'b', which must contain at least * 'size' bytes of data. Returns the first byte of data removed. */ void * -ofpbuf_pull(struct ofpbuf *b, size_t size) +ofpbuf_pull(struct ofpbuf *b, size_t size) { void *data = b->data; assert(b->size >= size); @@ -282,7 +363,35 @@ ofpbuf_pull(struct ofpbuf *b, size_t size) * head end of 'b' and returns the first byte removed. Otherwise, returns a * null pointer without modifying 'b'. */ void * -ofpbuf_try_pull(struct ofpbuf *b, size_t size) +ofpbuf_try_pull(struct ofpbuf *b, size_t size) { return b->size >= size ? ofpbuf_pull(b, size) : NULL; } + +/* Returns a string that describes some of 'b''s metadata plus a hex dump of up + * to 'maxbytes' from the start of the buffer. */ +char * +ofpbuf_to_string(const struct ofpbuf *b, size_t maxbytes) +{ + struct ds s; + + ds_init(&s); + ds_put_format(&s, "size=%zu, allocated=%zu, head=%zu, tail=%zu\n", + b->size, b->allocated, + ofpbuf_headroom(b), ofpbuf_tailroom(b)); + ds_put_hex_dump(&s, b->data, MIN(b->size, maxbytes), 0, false); + return ds_cstr(&s); +} + +/* Removes each of the "struct ofpbuf"s on 'list' from the list and frees + * them. */ +void +ofpbuf_list_delete(struct list *list) +{ + struct ofpbuf *b, *next; + + LIST_FOR_EACH_SAFE (b, next, list_node, list) { + list_remove(&b->list_node); + ofpbuf_delete(b); + } +}