diff --git a/src/core/pbuf.c b/src/core/pbuf.c index 319aadba..dd9ff64e 100644 --- a/src/core/pbuf.c +++ b/src/core/pbuf.c @@ -974,8 +974,8 @@ pbuf_take(struct pbuf *buf, const void *dataptr, u16_t len) /** * Creates a single pbuf out of a queue of pbufs. * - * @remark: The source pbuf 'p' is not freed by this function because that can - * be illegal in some places! + * @remark: Either the source pbuf 'p' is freed by this function or the original + * pbuf 'p' is returned, therefore the caller has to check the result! * * @param p the source pbuf * @param layer pbuf_layer of the new pbuf @@ -1042,3 +1042,115 @@ pbuf_fill_chksum(struct pbuf *p, u16_t start_offset, const void *dataptr, return ERR_OK; } #endif /* LWIP_CHECKSUM_ON_COPY */ + + /** Get one byte from the specified position in a pbuf + * WARNING: returns zero for offset >= p->tot_len + * + * @param p pbuf to parse + * @param offset offset into p of the byte to return + * @return byte at an offset into p OR ZERO IF 'offset' >= p->tot_len + */ +u8_t +pbuf_get_at(struct pbuf* p, u16_t offset) +{ + u16_t copy_from = offset; + struct pbuf* q = p; + + /* get the correct pbuf */ + while ((q != NULL) && (q->len <= copy_from)) { + copy_from -= q->len; + q = q->next; + } + /* return requested data if pbuf is OK */ + if ((q != NULL) && (q->len > copy_from)) { + return ((u8_t*)q->payload)[copy_from]; + } + return 0; +} + +/** Compare pbuf contents at specified offset with memory s2, both of length n + * + * @param p pbuf to compare + * @param offset offset into p at wich to start comparing + * @param s2 buffer to compare + * @param n length of buffer to compare + * @return zero if equal, nonzero otherwise + * (0xffff if p is too short, diffoffset+1 otherwise) + */ +u16_t +pbuf_memcmp(struct pbuf* p, u16_t offset, const void* s2, u16_t n) +{ + u16_t start = offset; + struct pbuf* q = p; + + /* get the correct pbuf */ + while ((q != NULL) && (q->len <= start)) { + start -= q->len; + q = q->next; + } + /* return requested data if pbuf is OK */ + if ((q != NULL) && (q->len > start)) { + u16_t i; + for(i = 0; i < n; i++) { + u8_t a = pbuf_get_at(q, start + i); + u8_t b = ((u8_t*)s2)[i]; + if (a != b) { + return i+1; + } + } + return 0; + } + return 0xffff; +} + +/** Find occurrence of mem (with length mem_len) in pbuf p, starting at offset + * start_offset. + * + * @param p pbuf to search, maximum length is 0xFFFE since 0xFFFF is used as + * return value 'not found' + * @param mem search for the contents of this buffer + * @param mem_len length of 'mem' + * @param start_offset offset into p at which to start searching + * @return 0xFFFF if substr was not found in p or the index where it was found + */ +u16_t +pbuf_memfind(struct pbuf* p, const void* mem, u16_t mem_len, u16_t start_offset) +{ + u16_t i; + u16_t max = p->tot_len - mem_len; + if (p->tot_len >= mem_len + start_offset) { + for(i = start_offset; i <= max; ) { + u16_t plus = pbuf_memcmp(p, i, mem, mem_len); + if (plus == 0) { + return i; + } else { + i += plus; + } + } + } + return 0xFFFF; +} + +/** Find occurrence of substr with length substr_len in pbuf p, start at offset + * start_offset + * WARNING: in contrast to strstr(), this one does not stop at the first \0 in + * the pbuf/source string! + * + * @param p pbuf to search, maximum length is 0xFFFE since 0xFFFF is used as + * return value 'not found' + * @param substr string to search for in p, maximum length is 0xFFFE + * @return 0xFFFF if substr was not found in p or the index where it was found + */ +u16_t +pbuf_strstr(struct pbuf* p, const char* substr) +{ + size_t substr_len; + if ((substr == NULL) || (substr[0] == 0) || (p->tot_len == 0xFFFF)) { + return 0xFFFF; + } + substr_len = strlen(substr); + if (substr_len >= 0xFFFF) { + return 0xFFFF; + } + return pbuf_memfind(p, substr, (u16_t)substr_len, 0); +} diff --git a/src/include/lwip/pbuf.h b/src/include/lwip/pbuf.h index b9227c58..239edd77 100644 --- a/src/include/lwip/pbuf.h +++ b/src/include/lwip/pbuf.h @@ -140,6 +140,11 @@ err_t pbuf_fill_chksum(struct pbuf *p, u16_t start_offset, const void *dataptr, u16_t len, u16_t *chksum); #endif /* LWIP_CHECKSUM_ON_COPY */ +u8_t pbuf_get_at(struct pbuf* p, u16_t offset); +u16_t pbuf_memcmp(struct pbuf* p, u16_t offset, const void* s2, u16_t n); +u16_t pbuf_memfind(struct pbuf* p, const void* mem, u16_t mem_len, u16_t start_offset); +u16_t pbuf_strstr(struct pbuf* p, const char* substr); + #ifdef __cplusplus } #endif