diff options
Diffstat (limited to 'modules/metadata/mod_unique_id.c')
| -rw-r--r-- | modules/metadata/mod_unique_id.c | 54 |
1 files changed, 37 insertions, 17 deletions
diff --git a/modules/metadata/mod_unique_id.c b/modules/metadata/mod_unique_id.c index 0b05fbf..2555749 100644 --- a/modules/metadata/mod_unique_id.c +++ b/modules/metadata/mod_unique_id.c @@ -26,6 +26,11 @@ #include "apr_general.h" /* for APR_OFFSETOF */ #include "apr_network_io.h" +#ifdef APR_HAS_THREADS +#include "apr_atomic.h" /* for apr_atomic_inc32 */ +#include "mpm_common.h" /* for ap_mpm_query */ +#endif + #include "httpd.h" #include "http_config.h" #include "http_log.h" @@ -104,7 +109,7 @@ typedef struct { /* * Sun Jun 7 05:43:49 CEST 1998 -- Alvaro * More comments: - * 1) The UUencoding prodecure is now done in a general way, avoiding the problems + * 1) The UUencoding procedure is now done in a general way, avoiding the problems * with sizes and paddings that can arise depending on the architecture. Now the * offsets and sizes of the elements of the unique_id_rec structure are calculated * in unique_id_global_init; and then used to duplicate the structure without the @@ -123,6 +128,10 @@ typedef struct { * XXX: thrashing. */ static unique_id_rec cur_unique_id; +static apr_uint32_t cur_unique_counter; +#ifdef APR_HAS_THREADS +static int is_threaded_mpm; +#endif /* * Number of elements in the structure unique_id_rec. @@ -160,6 +169,11 @@ static int unique_id_global_init(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *pt static void unique_id_child_init(apr_pool_t *p, server_rec *s) { +#ifdef APR_HAS_THREADS + is_threaded_mpm = 0; + ap_mpm_query(AP_MPMQ_IS_THREADED, &is_threaded_mpm); +#endif + ap_random_insecure_bytes(&cur_unique_id.root, sizeof(cur_unique_id.root)); @@ -168,28 +182,29 @@ static void unique_id_child_init(apr_pool_t *p, server_rec *s) * against restart problems, and a little less protection against a clock * going backwards in time. */ - ap_random_insecure_bytes(&cur_unique_id.counter, - sizeof(cur_unique_id.counter)); + ap_random_insecure_bytes(&cur_unique_counter, + sizeof(cur_unique_counter)); } -/* NOTE: This is *NOT* the same encoding used by base64encode ... the last two - * characters should be + and /. But those two characters have very special - * meanings in URLs, and we want to make it easy to use identifiers in - * URLs. So we replace them with @ and -. - */ +/* Use the base64url encoding per RFC 4648, avoiding characters which + * are not safe in URLs. ### TODO: can switch to apr_encode_*. */ static const char uuencoder[64] = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', - '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '@', '-', + '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '-', '_', }; +#ifndef APR_UINT16_MAX +#define APR_UINT16_MAX 0xffffu +#endif + static const char *gen_unique_id(const request_rec *r) { char *str; /* - * Buffer padded with two final bytes, used to copy the unique_id_red + * Buffer padded with two final bytes, used to copy the unique_id_rec * structure without the internal paddings that it could have. */ unique_id_rec new_unique_id; @@ -197,14 +212,24 @@ static const char *gen_unique_id(const request_rec *r) unique_id_rec foo; unsigned char pad[2]; } paddedbuf; + apr_uint32_t counter; unsigned char *x,*y; - unsigned short counter; int i,j,k; memcpy(&new_unique_id.root, &cur_unique_id.root, ROOT_SIZE); - new_unique_id.counter = cur_unique_id.counter; new_unique_id.stamp = htonl((unsigned int)apr_time_sec(r->request_time)); new_unique_id.thread_index = htonl((unsigned int)r->connection->id); +#ifdef APR_HAS_THREADS + if (is_threaded_mpm) + counter = apr_atomic_inc32(&cur_unique_counter); + else +#endif + counter = cur_unique_counter++; + + /* The counter is two bytes for the uuencoded unique id, in network + * byte order. + */ + new_unique_id.counter = htons(counter % APR_UINT16_MAX); /* we'll use a temporal buffer to avoid uuencoding the possible internal * paddings of the original structure */ @@ -236,11 +261,6 @@ static const char *gen_unique_id(const request_rec *r) } str[k++] = '\0'; - /* and increment the identifier for the next call */ - - counter = ntohs(new_unique_id.counter) + 1; - cur_unique_id.counter = htons(counter); - return str; } |