feat(lnm): implement content-length header parsing

lnm/include/lnm/common.h

@@ -1,6 +1,10 @@
 #ifndef LNM_COMMON
 #define LNM_COMMON
 
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
 #define LNM_RES(x)                                                             \
   {                                                                            \
     lnm_err res = x;                                                           \
@@ -20,13 +24,14 @@
 #define LNM_MIN(x, y) ((x) < (y) ? (x) : (y))
 #define LNM_MAX(x, y) ((x) > (y) ? (x) : (y))
 
-typedef enum {
+typedef enum lnm_err {
   lnm_err_ok = 0,
   lnm_err_failed_alloc,
   lnm_err_failed_network,
   lnm_err_failed_poll,
   lnm_err_not_setup,
-  lnm_err_bad_regex
+  lnm_err_bad_regex,
+  lnm_err_not_found,
 } lnm_err;
 
 typedef struct lnm_loop lnm_http_loop;
@@ -37,4 +42,41 @@ typedef struct lnm_http_step lnm_http_step;
 
 typedef struct lnm_http_route lnm_http_route;
 
+/**
+ * Returns whether the two strings are equal.
+ *
+ * @param s1 first string to compare
+ * @param s1_len length of `s1`
+ * @param s2 second string to compare
+ * @param s2_len length of `s2`
+ */
+bool lnm_strneq(const char *s1, size_t s1_len, const char *s2, size_t s2_len);
+
+/**
+ * Returns whether the two strings are equal, ignoring capitalisation.
+ *
+ * @param s1 first string to compare
+ * @param s1_len length of `s1`
+ * @param s2 second string to compare
+ * @param s2_len length of `s2`
+ */
+bool lnm_strnieq(const char *s1, size_t s1_len, const char *s2, size_t s2_len);
+
+/**
+ * Calculate integer exponentation.
+ *
+ * @param base
+ * @param power
+ */
+uint64_t lnm_ipow(uint64_t base, uint64_t power);
+
+/**
+ * Parse the given string into a number.
+ *
+ * @param s string to parse
+ * @param len length of s
+ * @return the parsed number, or 0 if the number is invalid
+ */
+uint64_t lnm_atoi(const char *s, size_t len);
+
 #endif

lnm/include/lnm/http/req.h

@@ -2,10 +2,12 @@
 #define LNM_HTTP_REQ
 
 #include <regex.h>
+#include <stdint.h>
 #include <stdlib.h>
 
 #include "picohttpparser.h"
 
+#include "lnm/common.h"
 #include "lnm/http/consts.h"
 
 #define LNM_HTTP_MAX_REQ_HEADERS 32
@@ -31,6 +33,7 @@ typedef struct lnm_http_req {
     struct phr_header arr[LNM_HTTP_MAX_REQ_HEADERS];
     size_t len;
   } headers;
+  uint64_t content_length;
 } lnm_http_req;
 
 typedef enum lnm_http_parse_err {
@@ -57,4 +60,26 @@ lnm_http_parse_err lnm_http_req_parse(lnm_http_req *req, char *buf, size_t len);
  */
 void lnm_http_req_reset(lnm_http_req *req);
 
+/**
+ * Retrieve a specific header from the request.
+ *
+ * @param out where to write pointer to header value
+ * @param out_len where to store length of out value
+ * @param req request to look for header in
+ * @param type type of header to look for
+ */
+lnm_err lnm_http_req_header_get(const char **out, size_t *out_len,
+                                lnm_http_req *req, lnm_http_header type);
+
+/**
+ * Retrieve a specific header from the request by specifying its name.
+ *
+ * @param out where to write pointer to header value
+ * @param out_len where to store length of out value
+ * @param req request to look for header in
+ * @param name name of the header; matches case-insensitive
+ */
+lnm_err lnm_http_req_header_get_s(const char **out, size_t *out_len,
+                                  lnm_http_req *req, const char *name);
+
 #endif