1 /* 2 * http_etag - HTTP ETag manipulation 3 * 4 * Copyright(c) 2015,2020 Glenn Strauss gstrauss()gluelogic.com All rights reserved 5 * License: BSD 3-clause (same as lighttpd) 6 */ 7 #include "first.h" 8 9 #include "http_etag.h" 10 11 #include <sys/stat.h> 12 #include <string.h> 13 14 #include "algo_md.h" 15 #include "buffer.h" 16 17 int 18 http_etag_matches (const buffer * const etag, const char *s, const int weak_ok) 19 { 20 if ('*' == s[0] && '\0' == s[1]) return 1; 21 if (buffer_is_blank(etag)) return 0; 22 23 uint32_t etag_sz = buffer_clen(etag); 24 const char *etag_ptr = etag->ptr; 25 26 if (etag_ptr[0] == 'W' && etag_ptr[1] == '/') { 27 if (!weak_ok) return 0; 28 etag_ptr += 2; 29 etag_sz -= 2; 30 } 31 32 while (*s) { 33 while (*s == ' ' || *s == '\t' || *s == ',') ++s; 34 if (s[0] == 'W' && s[1] == '/' ? (s+=2, weak_ok) : 1) { 35 if (0 == strncmp(s, etag_ptr, etag_sz) || *s == '*') { 36 s += (*s != '*' ? etag_sz : 1); 37 if (*s == '\0' || *s == ' ' || *s == '\t' || *s == ',') 38 return 1; 39 } 40 } 41 while (*s != '\0' && *s != ',') ++s; 42 } 43 return 0; 44 } 45 46 static void 47 http_etag_remix (buffer * const etag, const char * const str, const uint32_t len) 48 { 49 uint32_t h = dekhash(str, len, len); /*(pass len as initial hash value)*/ 50 #if 0 /*(currently never elen > 2; always cleared in http_etag_create())*/ 51 uint32_t elen = buffer_clen(etag); 52 if (elen > 2) {/*(expect "..." if set)*/ 53 h = dekhash(etag->ptr+1, elen-2, h); 54 buffer_truncate(etag, 1); 55 } 56 else { 57 buffer_clear(etag); 58 buffer_append_char(etag, '"'); 59 } 60 #else 61 /*buffer_clear(etag);*//*(currently always cleared in http_etag_create())*/ 62 buffer_append_char(etag, '"'); 63 #endif 64 buffer_append_int(etag, h); 65 buffer_append_char(etag, '"'); 66 } 67 68 void 69 http_etag_create (buffer * const etag, const struct stat * const st, const int flags) 70 { 71 if (0 == flags) return; 72 73 uint64_t x[4]; 74 uint32_t len = 0; 75 76 if (flags & ETAG_USE_INODE) 77 x[len++] = (uint64_t)st->st_ino; 78 79 if (flags & ETAG_USE_SIZE) 80 x[len++] = (uint64_t)st->st_size; 81 82 if (flags & ETAG_USE_MTIME) { 83 x[len++] = (uint64_t)st->st_mtime; 84 #ifdef st_mtime /* use high-precision timestamp if available */ 85 #if defined(__APPLE__) && defined(__MACH__) 86 x[len++] = (uint64_t)st->st_mtimespec.tv_nsec; 87 #else 88 x[len++] = (uint64_t)st->st_mtim.tv_nsec; 89 #endif 90 #endif 91 } 92 93 buffer_clear(etag); 94 http_etag_remix(etag, (char *)x, len << 3); 95 } 96