nvmem: layouts: ascii-env handle CRLF while parsing

Add validation and support for parsing of name/value pairs with CRLF line
endings.

Signed-off-by: George Moussalem <george.moussalem@outlook.com>
Link: https://github.com/openwrt/openwrt/pull/17935
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>

diff --git a/target/linux/generic/pending-6.6/809-03-nvmem-layouts-ascii-env-handle-CRLF-while-parsing.patch b/target/linux/generic/pending-6.6/809-03-nvmem-layouts-ascii-env-handle-CRLF-while-parsing.patch
new file mode 100644 (file)
index 0000000..ab5fc58
--- /dev/null
+++ b/target/linux/generic/pending-6.6/809-03-nvmem-layouts-ascii-env-handle-CRLF-while-parsing.patch
@@ -0,0 +1,58 @@
+From: George Moussalem <george.moussalem@outlook.com>
+Date: Thu, 06 Feb 2025 21:55:28 +0400
+Subject: [PATCH] nvmem: layouts: ascii-env handle CRLF while parsing
+
+The current driver supports LF line endings only.
+
+For CRLF-based line endings in the ASCII env, the length of the value of
+the variable passed to nvmem_layout_parse_mac_base is 18 bytes instead
+of an expected length of 17 causing the parsing to fail.
+So, let's add the ability to handle CRLF line endings by adding a
+condition to check if the value ends with a '\r' character and replace it
+with '\0' to properly parse the mac address.
+
+Tested on Linksys MX2000, MX5500, and SPNMX56.
+
+Signed-off-by: George Moussalem <george.moussalem@outlook.com>
+---
+--- a/drivers/nvmem/layouts/ascii-env.c
++++ b/drivers/nvmem/layouts/ascii-env.c
+@@ -25,18 +25,20 @@ struct ascii_env_match_data {
+ static int ascii_env_parse_cells(struct device *dev, struct nvmem_device *nvmem, uint8_t *buf,
+                                size_t data_len, const char delim)
+ {
+-      char *var, *value, *eq, *lf;
++      char *var, *value, *eq, *lf, *cr;
+       char *data = buf;
++      uint incr = 0;
+ 
+       /*
+        * Warning the inner loop take care of replacing '\n'
+        * with '\0', hence we can use strlen on value.
+        */
+       for (var = data; var < data + data_len && *var;
+-           var = value + strlen(value) + 1) {
++           var = value + strlen(value) + incr) {
+               struct nvmem_cell_info info = {};
+               struct device_node *child;
+               const char *label;
++              incr = 0;
+ 
+               eq = strchr(var, delim);
+               if (!eq)
+@@ -49,6 +51,15 @@ static int ascii_env_parse_cells(struct
+               if (!lf)
+                       break;
+               *lf = '\0';
++              incr++;
++
++              /* For CRLF based env, replace '\r' with '\0' too to use strlen
++               * for value, and increment var by one in loop for next variable */
++              cr = strchr(value, '\r');
++              if (cr) {
++                      *cr = '\0';
++                      incr++;
++              }
+ 
+               info.name = devm_kstrdup(dev, var, GFP_KERNEL);
+               if (!info.name)