Squash commits for public release

libs/libc/pwd/shadow.c

@@ -0,0 +1,116 @@
+#include <assert.h>
+#include <shadow.h>
+#include <stdio.h>
+#include <string.h>
+
+static FILE* spwdfile = NULL;
+static char tmp_buf[512];
+
+// spwd struct contains pointers to data which is
+// stored in spwd_buf
+static char spwd_buf[512];
+static spwd_t spwd_entry;
+
+static inline int spwd_part_to_int(char* part)
+{
+    int res = 0;
+    sscanf(part, "%d", &res);
+    return res;
+}
+
+static inline uint32_t spwd_part_to_uint(char* part)
+{
+    uint32_t res = 0;
+    sscanf(part, "%u", &res);
+    return res;
+}
+
+static spwd_t* parse_spwd_entry(char* res)
+{
+    int len = strlen(res);
+    int nxt_part = 0;
+    char* parts[10];
+
+    memcpy(spwd_buf, res, len);
+
+    parts[nxt_part++] = &spwd_buf[0];
+    for (int i = 0; i < len; i++) {
+        if (spwd_buf[i] == ':') {
+            parts[nxt_part++] = &spwd_buf[i + 1];
+            spwd_buf[i] = '\0';
+            if (nxt_part > 9) {
+                // More than 9 block.
+                return NULL;
+            }
+        }
+    }
+    spwd_buf[len] = '\0';
+
+    if (nxt_part != 9) {
+        return NULL;
+    }
+
+    spwd_entry.sp_namp = parts[0];
+    spwd_entry.sp_pwdp = parts[1];
+    spwd_entry.sp_lstchg = spwd_part_to_int(parts[2]);
+    spwd_entry.sp_min = spwd_part_to_int(parts[3]);
+    spwd_entry.sp_max = spwd_part_to_int(parts[4]);
+    spwd_entry.sp_warn = spwd_part_to_int(parts[5]);
+    spwd_entry.sp_inact = spwd_part_to_int(parts[6]);
+    spwd_entry.sp_expire = spwd_part_to_int(parts[7]);
+    spwd_entry.sp_flag = spwd_part_to_uint(parts[8]);
+    return &spwd_entry;
+}
+
+void setspent()
+{
+    spwdfile = fopen("/etc/shadow", "r");
+    if (spwdfile == NULL) {
+        // Raise an error
+    }
+}
+
+void endspent()
+{
+    if (spwdfile) {
+        fclose(spwdfile);
+        spwdfile = NULL;
+    }
+    memset(&spwd_entry, 0, sizeof(spwd_entry));
+}
+
+spwd_t* getspent()
+{
+    if (!spwdfile) {
+        setspent();
+    }
+
+    while (1) {
+        if (feof(spwdfile)) {
+            return NULL;
+        }
+
+        char* res = fgets(spwd_buf, 512, spwdfile);
+        if (!res || !res[0]) {
+            return NULL;
+        }
+
+        if (parse_spwd_entry(res)) {
+            return &spwd_entry;
+        }
+    }
+
+    return NULL;
+}
+
+spwd_t* getspnam(const char* name)
+{
+    spwd_t* spwd;
+    setspent();
+    while ((spwd = getspent())) {
+        if (!strcmp(spwd->sp_namp, name)) {
+            return spwd;
+        }
+    }
+    return NULL;
+}