[PATCH net-next 10/15] batman-adv: tvlv: extract tvlv header iterator
From: Simon Wunderlich <sw@simonwunderlich.de>
Date: 2026-06-30 14:06:34
Also in:
batman
Subsystem:
batman advanced, the rest · Maintainers:
Marek Lindner, Simon Wunderlich, Antonio Quartulli, Sven Eckelmann, Linus Torvalds
From: Sven Eckelmann <sven@narfation.org> batadv_tvlv_containers_contain() and batadv_tvlv_containers_process() are using the same code to iterate through the TVLV containers. To simplify the code, extract the shared portions of both functions. Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de> --- net/batman-adv/tvlv.c | 86 +++++++++++++++++++++++++------------------ 1 file changed, 51 insertions(+), 35 deletions(-)
diff --git a/net/batman-adv/tvlv.c b/net/batman-adv/tvlv.c
index 1c9fb21985f6a..49bf2ed9ecdc3 100644
--- a/net/batman-adv/tvlv.c
+++ b/net/batman-adv/tvlv.c@@ -442,6 +442,54 @@ static int batadv_tvlv_call_handler(struct batadv_priv *bat_priv, return NET_RX_SUCCESS; } +/** + * batadv_tvlv_hdr_next() - move a tvlv buffer cursor to the next container + * @tvlv_value: cursor into the tvlv buffer, advanced past the returned + * container's content on success + * @tvlv_value_len: remaining length of the tvlv buffer, reduced by the returned + * container's size on success + * + * Parses a single container header at the current cursor position and, if a + * complete container is available, advances the cursor and remaining length + * past it. The returned header stays valid; its content is located at + * (returned header + 1) and is ntohs(hdr->len) bytes long. + * + * Return: pointer to the next tvlv container header, or NULL if no further + * complete container is present in the buffer. + */ +static struct batadv_tvlv_hdr *batadv_tvlv_hdr_next(void **tvlv_value, u16 *tvlv_value_len) +{ + struct batadv_tvlv_hdr *tvlv_hdr; + u16 tvlv_value_cont_len; + void *tvlv_value_cont; + u16 tvlv_len; + + tvlv_value_cont = *tvlv_value; + tvlv_len = *tvlv_value_len; + + if (tvlv_len < sizeof(*tvlv_hdr)) + return NULL; + + tvlv_hdr = tvlv_value_cont; + tvlv_value_cont_len = ntohs(tvlv_hdr->len); + tvlv_value_cont = tvlv_hdr + 1; + tvlv_len -= sizeof(*tvlv_hdr); + + if (tvlv_value_cont_len > tvlv_len) + return NULL; + + /* the next tvlv header is accessed assuming (at least) 2-byte + * alignment, so it must start at an even offset. + */ + if (tvlv_value_cont_len & 1) + return NULL; + + *tvlv_value = (u8 *)tvlv_value_cont + tvlv_value_cont_len; + *tvlv_value_len = tvlv_len - tvlv_value_cont_len; + + return tvlv_hdr; +} + /** * batadv_tvlv_containers_contain() - check if a tvlv buffer holds a container * @tvlv_value: tvlv content
@@ -457,28 +505,10 @@ static bool batadv_tvlv_containers_contain(void *tvlv_value, u8 version) { struct batadv_tvlv_hdr *tvlv_hdr; - u16 tvlv_value_cont_len; - - while (tvlv_value_len >= sizeof(*tvlv_hdr)) { - tvlv_hdr = tvlv_value; - tvlv_value_cont_len = ntohs(tvlv_hdr->len); - tvlv_value = tvlv_hdr + 1; - tvlv_value_len -= sizeof(*tvlv_hdr); - - if (tvlv_value_cont_len > tvlv_value_len) - break; - - /* the next tvlv header is accessed assuming (at least) 2-byte - * alignment, so it must start at an even offset. - */ - if (tvlv_value_cont_len & 1) - break; + while ((tvlv_hdr = batadv_tvlv_hdr_next(&tvlv_value, &tvlv_value_len))) { if (tvlv_hdr->type == type && tvlv_hdr->version == version) return true; - - tvlv_value = (u8 *)tvlv_value + tvlv_value_cont_len; - tvlv_value_len -= tvlv_value_cont_len; } return false;
@@ -511,20 +541,8 @@ int batadv_tvlv_containers_process(struct batadv_priv *bat_priv, u8 cifnotfound = BATADV_TVLV_HANDLER_OGM_CIFNOTFND; int ret = NET_RX_SUCCESS; - while (tvlv_value_len >= sizeof(*tvlv_hdr)) { - tvlv_hdr = tvlv_value; + while ((tvlv_hdr = batadv_tvlv_hdr_next(&tvlv_value, &tvlv_value_len))) { tvlv_value_cont_len = ntohs(tvlv_hdr->len); - tvlv_value = tvlv_hdr + 1; - tvlv_value_len -= sizeof(*tvlv_hdr); - - if (tvlv_value_cont_len > tvlv_value_len) - break; - - /* the next tvlv header is accessed assuming (at least) 2-byte - * alignment, so it must start at an even offset. - */ - if (tvlv_value_cont_len & 1) - break; tvlv_handler = batadv_tvlv_handler_get(bat_priv, tvlv_hdr->type,
@@ -532,11 +550,9 @@ int batadv_tvlv_containers_process(struct batadv_priv *bat_priv, ret |= batadv_tvlv_call_handler(bat_priv, tvlv_handler, packet_type, orig_node, skb, - tvlv_value, + tvlv_hdr + 1, tvlv_value_cont_len); batadv_tvlv_handler_put(tvlv_handler); - tvlv_value = (u8 *)tvlv_value + tvlv_value_cont_len; - tvlv_value_len -= tvlv_value_cont_len; } if (packet_type != BATADV_IV_OGM &&
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2.47.3