Date: Sat, 23 Sep 2023 16:23:53 GMT From: Alexander Motin <mav@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: f80babf906b7 - main - kern_sysctl: Make name2oid() non-destructive to the name Message-ID: <202309231623.38NGNrmQ003926@gitrepo.freebsd.org>
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The branch main has been updated by mav: URL: https://cgit.FreeBSD.org/src/commit/?id=f80babf906b7be51b2a031ef26525893c7bf4e31 commit f80babf906b7be51b2a031ef26525893c7bf4e31 Author: Alexander Motin <mav@FreeBSD.org> AuthorDate: 2023-09-23 16:13:46 +0000 Commit: Alexander Motin <mav@FreeBSD.org> CommitDate: 2023-09-23 16:13:46 +0000 kern_sysctl: Make name2oid() non-destructive to the name It is not the first time I see it panicking while trying to modify const memory. Lets make it safer and easier to use. While there, mark few functions using it also const. MFC after: 10 days --- sys/kern/kern_sysctl.c | 34 +++++++++++++++++++++++++++------- 1 file changed, 27 insertions(+), 7 deletions(-) diff --git a/sys/kern/kern_sysctl.c b/sys/kern/kern_sysctl.c index 780eb6099b07..a4bfe8e21aed 100644 --- a/sys/kern/kern_sysctl.c +++ b/sys/kern/kern_sysctl.c @@ -127,7 +127,7 @@ static int sysctl_remove_oid_locked(struct sysctl_oid *oidp, int del, int recurse); static int sysctl_old_kernel(struct sysctl_req *, const void *, size_t); static int sysctl_new_kernel(struct sysctl_req *, void *, size_t); -static int name2oid(char *, int *, int *, struct sysctl_oid **); +static int name2oid(const char *, int *, int *, struct sysctl_oid **); static struct sysctl_oid * sysctl_find_oidname(const char *name, struct sysctl_oid_list *list) @@ -143,6 +143,21 @@ sysctl_find_oidname(const char *name, struct sysctl_oid_list *list) return (NULL); } +static struct sysctl_oid * +sysctl_find_oidnamelen(const char *name, size_t len, + struct sysctl_oid_list *list) +{ + struct sysctl_oid *oidp; + + SYSCTL_ASSERT_LOCKED(); + SYSCTL_FOREACH(oidp, list) { + if (strncmp(oidp->oid_name, name, len) == 0 && + oidp->oid_name[len] == '\0') + return (oidp); + } + return (NULL); +} + /* * Initialization of the MIB tree. * @@ -978,7 +993,7 @@ SYSINIT(sysctl, SI_SUB_KMEM, SI_ORDER_FIRST, sysctl_register_all, NULL); #ifdef VIMAGE static void -sysctl_setenv_vnet(void *arg __unused, char *name) +sysctl_setenv_vnet(void *arg __unused, const char *name) { struct sysctl_oid *oidp; int oid[CTL_MAXNAME]; @@ -1001,7 +1016,7 @@ out: } static void -sysctl_unsetenv_vnet(void *arg __unused, char *name) +sysctl_unsetenv_vnet(void *arg __unused, const char *name) { struct sysctl_oid *oidp; int oid[CTL_MAXNAME]; @@ -1419,21 +1434,26 @@ static SYSCTL_NODE(_sysctl, CTL_SYSCTL_NEXTNOSKIP, nextnoskip, CTLFLAG_RD | CTLFLAG_MPSAFE | CTLFLAG_CAPRD, sysctl_sysctl_next, ""); static int -name2oid(char *name, int *oid, int *len, struct sysctl_oid **oidpp) +name2oid(const char *name, int *oid, int *len, struct sysctl_oid **oidpp) { struct sysctl_oid *oidp; struct sysctl_oid_list *lsp = &sysctl__children; + const char *n; SYSCTL_ASSERT_LOCKED(); for (*len = 0; *len < CTL_MAXNAME;) { - oidp = sysctl_find_oidname(strsep(&name, "."), lsp); + n = strchrnul(name, '.'); + oidp = sysctl_find_oidnamelen(name, n - name, lsp); if (oidp == NULL) return (ENOENT); *oid++ = oidp->oid_number; (*len)++; - if (name == NULL || *name == '\0') { + name = n; + if (*name == '.') + name++; + if (*name == '\0') { if (oidpp) *oidpp = oidp; return (0); @@ -2999,7 +3019,7 @@ db_show_sysctl_all(int *oid, size_t len, int flags) * Show a sysctl by its user facing string */ static int -db_sysctlbyname(char *name, int flags) +db_sysctlbyname(const char *name, int flags) { struct sysctl_oid *oidp; int oid[CTL_MAXNAME];
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