diff --git a/drivers/char/lrng/Makefile b/drivers/char/lrng/Makefile index 29724c65287d1..ac97f0b11cb78 100644 --- a/drivers/char/lrng/Makefile +++ b/drivers/char/lrng/Makefile @@ -9,3 +9,4 @@ obj-y += lrng_pool.o lrng_aux.o \ lrng_interfaces.o obj-$(CONFIG_NUMA) += lrng_numa.o +obj-$(CONFIG_SYSCTL) += lrng_proc.o diff --git a/drivers/char/lrng/lrng_interfaces.c b/drivers/char/lrng/lrng_interfaces.c index 3a56bfdca01ed..4b8c568491121 100644 --- a/drivers/char/lrng/lrng_interfaces.c +++ b/drivers/char/lrng/lrng_interfaces.c @@ -38,8 +38,6 @@ static DECLARE_WAIT_QUEUE_HEAD(lrng_write_wait); static DECLARE_WAIT_QUEUE_HEAD(lrng_init_wait); static struct fasync_struct *fasync; -struct ctl_table random_table[]; - /********************************** Helper ***********************************/ /* Is the DRNG seed level too low? */ diff --git a/drivers/char/lrng/lrng_internal.h b/drivers/char/lrng/lrng_internal.h index 421a6f34a5a01..d47eefe12efb4 100644 --- a/drivers/char/lrng/lrng_internal.h +++ b/drivers/char/lrng/lrng_internal.h @@ -113,7 +113,11 @@ void lrng_cc20_init_state(struct chacha20_state *state); /********************************** /proc *************************************/ +#ifdef CONFIG_SYSCTL +void lrng_pool_inc_numa_node(void); +#else static inline void lrng_pool_inc_numa_node(void) { } +#endif /****************************** LRNG interfaces *******************************/ diff --git a/drivers/char/lrng/lrng_proc.c b/drivers/char/lrng/lrng_proc.c new file mode 100644 index 0000000000000..30bc0a1a66324 --- /dev/null +++ b/drivers/char/lrng/lrng_proc.c @@ -0,0 +1,185 @@ +// SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause +/* + * LRNG proc and sysctl interfaces + * + * Copyright (C) 2016 - 2021, Stephan Mueller + */ + +#include +#include +#include +#include +#include + +#include "lrng_internal.h" +#include "lrng_sw_noise.h" + +/* + * This function is used to return both the bootid UUID, and random + * UUID. The difference is in whether table->data is NULL; if it is, + * then a new UUID is generated and returned to the user. + * + * If the user accesses this via the proc interface, the UUID will be + * returned as an ASCII string in the standard UUID format; if via the + * sysctl system call, as 16 bytes of binary data. + */ +static int lrng_proc_do_uuid(struct ctl_table *table, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + struct ctl_table fake_table; + unsigned char buf[64], tmp_uuid[16], *uuid; + + uuid = table->data; + if (!uuid) { + uuid = tmp_uuid; + generate_random_uuid(uuid); + } else { + static DEFINE_SPINLOCK(bootid_spinlock); + + spin_lock(&bootid_spinlock); + if (!uuid[8]) + generate_random_uuid(uuid); + spin_unlock(&bootid_spinlock); + } + + sprintf(buf, "%pU", uuid); + + fake_table.data = buf; + fake_table.maxlen = sizeof(buf); + + return proc_dostring(&fake_table, write, buffer, lenp, ppos); +} + +static int lrng_proc_do_entropy(struct ctl_table *table, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + struct ctl_table fake_table; + int entropy_count; + + entropy_count = lrng_avail_entropy(); + + fake_table.data = &entropy_count; + fake_table.maxlen = sizeof(entropy_count); + + return proc_dointvec(&fake_table, write, buffer, lenp, ppos); +} + +static int lrng_proc_do_poolsize(struct ctl_table *table, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + struct ctl_table fake_table; + int entropy_count; + + /* LRNG can at most retain entropy in per-CPU pools and aux pool */ + entropy_count = lrng_get_digestsize() + lrng_pcpu_avail_pool_size(); + + fake_table.data = &entropy_count; + fake_table.maxlen = sizeof(entropy_count); + + return proc_dointvec(&fake_table, write, buffer, lenp, ppos); +} + +static int lrng_min_write_thresh; +static int lrng_max_write_thresh = LRNG_MAX_DIGESTSIZE; +static char lrng_sysctl_bootid[16]; +static int lrng_drng_reseed_max_min; + +struct ctl_table random_table[] = { + { + .procname = "poolsize", + .maxlen = sizeof(int), + .mode = 0444, + .proc_handler = lrng_proc_do_poolsize, + }, + { + .procname = "entropy_avail", + .maxlen = sizeof(int), + .mode = 0444, + .proc_handler = lrng_proc_do_entropy, + }, + { + .procname = "write_wakeup_threshold", + .data = &lrng_write_wakeup_bits, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = &lrng_min_write_thresh, + .extra2 = &lrng_max_write_thresh, + }, + { + .procname = "boot_id", + .data = &lrng_sysctl_bootid, + .maxlen = 16, + .mode = 0444, + .proc_handler = lrng_proc_do_uuid, + }, + { + .procname = "uuid", + .maxlen = 16, + .mode = 0444, + .proc_handler = lrng_proc_do_uuid, + }, + { + .procname = "urandom_min_reseed_secs", + .data = &lrng_drng_reseed_max_time, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + .extra1 = &lrng_drng_reseed_max_min, + }, + { } +}; + +/* Number of online DRNGs */ +static u32 numa_drngs = 1; + +void lrng_pool_inc_numa_node(void) +{ + numa_drngs++; +} + +static int lrng_proc_type_show(struct seq_file *m, void *v) +{ + struct lrng_drng *lrng_drng_init = lrng_drng_init_instance(); + unsigned long flags = 0; + unsigned char buf[390]; + + lrng_drng_lock(lrng_drng_init, &flags); + snprintf(buf, sizeof(buf), + "DRNG name: %s\n" + "Hash for reading entropy pool: %s\n" + "Hash for operating aux entropy pool: %s\n" + "LRNG security strength in bits: %d\n" + "per-CPU interrupt collection size: %u\n" + "number of DRNG instances: %u\n" + "Standards compliance: %s%s\n" + "High-resolution timer: %s\n" + "LRNG minimally seeded: %s\n" + "LRNG fully seeded: %s\n" + "Continuous compression: %s\n", + lrng_drng_init->crypto_cb->lrng_drng_name(), + lrng_drng_init->crypto_cb->lrng_hash_name(), + lrng_drng_init->crypto_cb->lrng_hash_name(), + lrng_security_strength(), + LRNG_DATA_NUM_VALUES, + numa_drngs, + lrng_sp80090b_compliant() ? "SP800-90B " : "", + lrng_sp80090c_compliant() ? "SP800-90C " : "", + lrng_pool_highres_timer() ? "true" : "false", + lrng_state_min_seeded() ? "true" : "false", + lrng_state_fully_seeded() ? "true" : "false", + lrng_pcpu_continuous_compression_state() ? "true" : "false"); + lrng_drng_unlock(lrng_drng_init, &flags); + + seq_write(m, buf, strlen(buf)); + + return 0; +} + +static int __init lrng_proc_type_init(void) +{ + proc_create_single("lrng_type", 0444, NULL, &lrng_proc_type_show); + return 0; +} + +module_init(lrng_proc_type_init);